Hernias

In general surgery everyone has a hernia. Or just about everyone. General surgery clinic is full of them. Patient walks in and I can diagnose a hernia before they’ve even said hello.

I have scrubbed in and assisted with two open inguinal hernia repairs- where we opened up the inguinal canal, pushed the hernia back in through the deep inguinal ring, whilst protecting the spermatic cord and vasculature and the ilioinguinal nerve (I held someone’s spermatic cord- weird…just weird), placed a mesh over the hernia, in between the conjoint tendon and external oblique muscle layer, and then stitched the patient back up. Job done.

 

 

Image result for conjoint tendon inguinal hernia repair

Indirect inguinal hernia. Cut, push it back in, place mesh, patch it up. Easy surgery. Ready to go solo for the next one…

 

Scrubbing in, for anyone that doesn’t know, is when you become a pure sterile being, and only the scrubbed up can touch you. The scrubbed up are the only ones that can touch the site of the operation and the sterile equipment that is used.

Scrubbing in is great in that you get a really close view of what is going on and depending on the surgeon, you can get really good teaching throughout the procedure. You also help out a bit with the surgery and feel like a useful part of the team, even if it is just retracting tissue and cutting sutures. But being scrubbed up is going to take some getting used to. Firstly, the mask. I have to wear mine upside down because there is a wire bit at the top that hurts my nose and even then, I still feel like I’m suffocating. Then there is the trying to put your gloves on without actually touching the outside of them. Ummm…help? (Fortunately, a lovely nurse with the cutest personality showed me the tricks).  And the not being able to touch your face to pull down the mask that is suffocating you. And the bending over the patient for a prolonged period, very tense because you’re new at this and haven’t discovered the most relaxed positions to hold and you’re grasping onto the retractors so tightly because you don’t want to be the incompetent medical student that let go at the most crucial point and ruined the entire surgery.


Abdominal wall hernias     

Definition: a hernia is a protrusion of a viscus or part of a viscus through a defect of the walls of its containing cavity into an abnormal position.

Hernias can be:

Irreducible: cannot be pushed back into the right place

Incarcerated: contents of the hernia sac are stuck inside by adhesions

Obstructed: in GI hernias, bowel contents cannot pass through them

Strangulated: ischaemia occurs as the blood supply to the hernia contents is compromised

Aetiology/ risk factors:

Types of hernias:

Inguinal– divided into direct and indirect inguinal hernias. Both originating above the inguinal ligament. May descend into scrotum. More common on the right.

Indirect = pass through the internal/deep inguinal ring and, if large, out through the external/superficial ring. Can strangulate. (80%)

Image result for hesselbach's triangle   –Direct = push their way directly forward through the posterior wall of the inguinal canal, into a defect in the abdominal wall, medial to the inferior epigastric vessels (within Hesselbach’s triangle = inguinal ligament, rectus abdominis, epigastric vessels). Reduce easily and rarely strangulate. (20%)

To distinguish clinically, reduce the hernia so it’s popped back into place. Then place your fingers, covering the internal ring, approximately mid-way between the ASIS and the pubic tubercle. Then, ask them to cough and if it is an indirect hernia, you should feel it trying to come out as you obstruct it.

Femoral– peritoneal sac, often with abdominal contents, protrudes through the femoral canal, presenting as a mass, originating below the inguinal ligament.

Femoral hernias are more likely to be irreducible and frequently strangulate because of rigid walls of femoral canal. They are often small and have a tight neck so can go unnoticed until they become strangulated or obstructed.

Image result for inguinal and femoral hernia

Inguinal hernias appear through the external inguinal ring, above and medial to the pubic tubercle.

Femoral hernias appear through the femoral canal below and lateral to the pubic tubercle. (Also medial to the femoral vein, artery and nerve)

herniaUmbilical herniation through umbilicus. Can occur from birth due to persistent defect in the transversalis fascia- the umbilical ring, through which the umbilical vessels passed to the fetus.

Paraumbilical occurs just above or just below the umbilicus. Usually bowel or omentum.

Epigastric pass through linea alba (fibrous structure down the midline of abdomen), above the umbilicus in the epigastric region

Incisional follow breakdown of muscle closure after surgery

 

Less common:

Spigelian– through linea semilunaris at the lateral edge of the rectus sheath, below and lateral to umbilicus

Lumbar– through the inferior or superior lumbar triangles in the posterior abdominal wall

Image result for lumbar triangle

Richter’s– involve bowel wall only- not the whole lumen

Image result for richter's hernia

Maydl’s– involve a herniating double loop of bowel. Strangulated portion may reside as a single connecting loop in the abdominal cavity.

Image result for maydl's hernia

Littre’s– hernia sack’s containing strangulated Meckel’s diverticulum (congenital diverticulum in the distal ileum)

Obturator– through the obturator canal. Typically there is pain along medial side of thigh in a thin woman.

Related image

Sciatic– through the lesser sciatic foramen

Sliding– contain a partially extraperitoneal structure e.g. caecum/ sigmoid colon. The sac does not completely surround the contents.

Image result for sliding hernia

R/Fs:

Raised intra-abdominal pressure: chronic cough, constipation, urinary obstruction (prostatism), heavy lifting, ascites    -past abdominal surgery, obesity, age

-Transversalis fascia and abdominal muscle weakness, diastasis recti (recti muscle separation)

-Inguinal: male

-Prematurity is a risk factor for congenital indirect inguinal hernias in males due to patent procesus vaginalis.

-Femoral: female due to wider femoral canal

-Incisional hernias = surgical scar

Epidemiology:

-Inguinal hernias are the commonest type of hernia (25x more than femoral) and are far more common in men (8x).

-Indirect inguinal hernias occur in 4% of all male infants.

-Peak age for inguinal hernias in adults = 55-85 yrs.

-Femoral hernias are found more often in women (4x), especially in middle aged and elderly.

-True umbilical hernias occur in 4% of live births. More common in Afro-Caribbeans, Down-Syndrome, and congenital hypothyroidism.

Symptoms:

-Lump/bulge that may be uncomfortable, though often not

-Obstructed GI hernias: vomiting, nausea, anorexia, constipation, colicky abdominal pain

Painful if strangulated

Signs:

-Palpable or visible lump/ bulge at characteristic site, often non-tender and soft

-Hernia may be reducible- able to be pushed back into place-or irreducible e.g. if incarcerated.

-May have a cough impulse- swelling expands upon coughing

-Auscultation may reveal bowels sounds within hernia

-Obstructed GI hernias: distended abdomen, ‘tinkling’ bowel sounds

-Tender, red, swollen hernia if strangulated

Investigations:

If acute with painful irreducible hernia: FBC, U&Es, clotting, Group and Save (if operation likely), ABG (metabolic acidosis in bowel ischaemia due to increased lactate)

Abdominal X-ray: may show bowel obstruction, in emergency cases

Hernias can be diagnosed on clinical examination but may do imaging if doubt about nature of swelling.

Ultrasound (may do CT): visualise hernia if a differential diagnosis is suspected.

Herniogram: X-ray with contrast injected into peritoneal cavity, can be performed in elective cases where suspected

Management:

Conservative: Asymptomatic hernias with a large neck may require no treatment.

Inguinal truss- belt that keeps reduced inguinal hernia from protruding (if unfit or unwilling for surgery).

-if a long-standing hernia becomes painful and irreducible, try to reduce it to prevent strangulation and necrosis

Emergency: resuscitation with rehydration and correction of electrolyte imbalances, placement of NG tube if vomiting, antibiotics if signs of sepsis and surgical repair as definitive treatment.

Surgical repair:

-elective correction indicated for symptomatic, narrow-necked or irreducible hernias

-diet (if overweight) and stop smoking pre-op

-principles involve dissection of the sac, observing and reducing the contents, excising the sac and repairing the defect e.g. with non-absorbable sutures or by using a mesh

-in mesh repairs, a polypropylene mesh reinforces the posterior wall

-surgery is fairly simple and can be performed as a day case

-can be performed open or laparoscopic ally

-emergency surgery needed for obstructed or strangulated hernias. Laparotomy with bowel resection may be indicated if gangrenous bowel is present within the hernia.

Herniotomy- ligation and excision of sac

Herniorrhaphy- repair of the hernia defect

-with congenital indirect inguinal hernias, surgical repair is required, but reinforcement of the posterior wall e.g. with a mesh, is not needed as the internal ring has not been chronically dilated.

-surgical repair of congenital umbilical hernia is rarely needed in children as most resolve by age 3

Complications:

-strangulation (common in femoral hernias → bowel obstruction → bowel ischaemia  → bowel gangrene- may necessitate surgical resection

-Amyand’s hernia = acute appendicitis is a right inguinal hernia

complications of surgery:

-bleeding, wound/ mesh infection, seroma (pocket of clear serous fluid that sometimes develops after surgery), pain, haematoma

-damage to surrounding structures during repair-e.g. spermatic cord or ilioinguinal nerve in inguinal hernia repair, loss of sensation/ numbness over groin area on that side.

-scrotal or penile oedema, testicular ischaemia, osteitis pubis- in inguinal repair

-narrowing femoral vein during femoral hernia repair → venous thrombosis

Prognosis:

Untreated, most hernias usually do not regress and may progressively enlarge. Umbilical hernias tend to regress by 2/3 years of age.

Patient can return to work after ≤ 2 weeks post-op if all well.

Hernias may recur after surgery.  < 2% using mesh techniques.

References: Cheese & Onion, Rapid Surgery
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