Abdominal Wall Hernias Types, Causes and Treatment

Describe general principles of management of abdominal wall hernias and the basic operative approach.

1. Herniotomy: Excision of hernial saNo repair is required and is done only in children.
2. Hernioplasty: Strengthening of the posterior wall— mostly by prolene mesh is the most popular surgery called Lichtenstein repair. Details of hernioplasty are given below. It can be done by open or laparoscopic methoDetails are also available in the operative surgery.
3. Herniorrhaphy: The approximation of conjoined tendon to inguinal ligament by using nonabsorbable sutures is called Bassini’s herniorrhaphy. It is not done nowadays because of the high chances of recurrence. Hence it is not discussed here.

Hernioplasty

There are two types of hernioplasties.

1. Lichtenstein repair:

• The posterior wall (Lichtenstein repair) of the inguinal canal is strengthened by a prolene mesh or Marlex mesh.
• The fibroblasts and capillaries grow over the mesh, converting it into a thick fibrous sheath and strengthening the posterior wall.
• The mesh is fixed inferiorly to the lacunar and inguinal ligaments, medially to overlap the rectus sheath, and fixed to the fascia over the pubic bone. A few interrupted sutures are put in to fix it to the transversalis fascia
• Laterally, an artificial deep ring is created by the crossing of both the upper and lower leaves of the mesh.
• To attain this, a slit is given on one side of the mesh. (Lacunar ligament is that portion of the inguinal ligament that extends backward and upwards to the pectineal line and forms the medial margin of the femoral ring).

Lichtenstein Repair

• Polypropylene mesh is used.
• 8 × 16 cm mesh is tailored to the patient’s requirement.
• Preparation of mesh: Corners can be cut so as to give a round shape. A slit is given on the lateral border of the mesh at the junction of the lower one-third and upper two-thirds, to allow a spermatic cord to pass through. The two tails (slit-ends) are overlapped.
• Suturing: Medially, the mesh overlaps the pubic tubercle and is sutured over the tissue of symphysis (avoid pubic bone to prevent osteitis pubis). Laterally, the two tails are placed beyond the deep ring and sutureInferiorly, it is sutured to inguinal and lacunar ligaments and superiorly to the conjoined tendon

Advantages of Polypropylene Mesh

• High tensile strength
• Biocompatible, nonabsorbable
• Monofilament strong, elastic, and transparent mesh
• Ideal porosity for high visibility and colonisation
• Strong mechanical reinforcement
• Encourages rapid ingrowth of connective tissue
• Cheaper
• Flexible for any anatomic placement

Advantages of Light Weight and Large Pores Mesh

• Less shrinkage of mesh, more flexibility, better tissue integration, and better comfort.

Characteristics of the ideal mesh

• Biocompatibility means it should not do any harm, and should be chemically and physically inert.
• The risk of infection should not be there.
• Handling should be good.
• Economical
• Longevity

2. Prolene (polypropylene) nylon darning:

• Suturing the conjoined tendon to the inguinal ligament without tension in a criss-cross manner by using prolene suture material (handmade mesh).
• This is preferred in direct and indirect hernias described by Maloney.

Biological Mesh

These are sterilized sheets of connective tissue derived from human or animal dermis or porcine intestinal submucosa:

• They are decellularised
• Like the mesh, they provide a scaffold for connective tissue to grow and collagen deposition.
• Enzymatic reaction takes place in the host followed by fibrous tissue formation.
• Advantages: Chronic inflammation and foreign body reaction, stiffness and fibrosis, and mesh infection are uncommon—usually do not occur.
• They can be used in presence of infection.
• They are very expensive.

Other Surgeries for Inguinal Hernia

1. Shouldice repair
   • It is the most popular tensionless method wherein only local tissues are used.
   • After opening the inguinal canal, a herniotomy is done.
   • Transversalis fascia, which forms the posterior wall, is incised from the internal ring to the pubic tubercles.
   • Then, upper and lower flaps of transversalis fascia are sutured in a double-breasting manner by using nonabsorbable sutures such as 34 gauge stainless steel wire, polyamide or polypropylene. This is the first layer of Shouldice repair.
   • The second layer is like Bassini’s, wherein conjoined tendon is sutured to the inguinal ligament by using nonabsorbable sutures.
   • The third layer is completed by suturing the upper flap of external oblique aponeurosis to the inguinal ligament.
   • The results have been good in Shouldice’s hands. The operation needs expertise.
2. Nyhus repair:
   • Ideally indicated in bilateral direct hernia or recurrent hernia, wherein a broad mesh is kept in the preperitoneal space.
   • It requires a single large incision covering both groins. However, the same surgery now can be done laparoscopically by keeping a mesh in the extraperitoneal space.
3. Dasarda technique: In this operation, a strip of external oblique aponeurosis is prepared isolated but still connected medially and laterally to the external oblique muscle, and sutured to conjoined tendon and inguinal ligament below.
4. What is a hernia system? A two-layered mesh is used—one to place deep to transversalis fascia (with a finger in the deep ring, blind and blunt dissection is done to develop a deep plane) and the other in front of the transversalis fascia.
5. What are mesh plug repairs? These are simple plugs of mesh inserted into the deep ring. It is a simple procedure but mesh migration and seroma within the mesh called Meshoma are common.

Rare/uncommon surgeries

1. Kuntz operation: In this operation, the spermatic cord is divided at the deep ring and it is removed along with the testis, so that the deep ring can be permanently closed, and hernia never recurs.
   • It is indicated in elderly patients with recurrent hernia and poor abdominal muscle tone. Hamilton Bailey’s operation—cord is divided but testis is retained.
2. Stoppa repair:¹ The Stoppa repair is a tension-free type of hernia repair. It is performed by wrapping the lower part of the parietal peritoneum with prosthetic mesh and placing it at a preperitoneal level over Fruchaud’s myopectineal orifice. This operation is also known as giant prosthetic reinforcement of the visceral sac (GPRVS).

Complications Of Hernia Surgery

These are common complications after surgery. Often they are mild and not so worrisome. However, some of the complications can be serious and require immediate attention and treatment.

1. Complications during surgery

• Injury to the iliac vessels: The most serious but rare complication is an injury to the iliac vessels. It can happen in thin patients when suturing of the inguinal ligament is done from the lateral to the medial side.
  • The sudden jet of fresh red blood indicates that the bite has been taken through the artery.
  • It is better to call the vascular surgeon, extend the incision, have a proximal control, suture directly, or do a resection and end-to-end anastomosis. They have to be anticoagulated with low molecular weight heparin followed by oral anticoagulants.
• Injury to the urinary bladder: This can happen when anatomy is not clear as in a few giant or scrotal hernias, perineal hernias, or distortion due to previous surgery.
  • The sudden finding of clear fluid with a urinary smell means bladder injury. Immediate repair with 2–0 vicryl followed by urinary catheter placement for 3 weeks is the treatment.

2. Early postoperative period

• Pain: Pain is common due to the incision in the skin and some degrees of retraction of structures such as the inguinal ligament downwards and the conjoint tendon upwards. The pain can be decreased by local anesthetic infiltration, e.g. bupivacaine 0.25%—20 ml.
• Bleeding: Perfect hemostasis is the aim of all surgeries. In spite of this, a few bleeders may open up, mostly venous blood—may be pampiniform plexus veins or arterial blood from the inferior epigastric artery.
• The bleeding may stop with a compression bandage. Otherwise, exploration and ligation of bleeders need to be done in the operation theatre.
• Urinary retention is common, more so in males: Pain, spinal or epidural anesthesia, sedatives, and lack of privacy are contributing factors. Provide analgesia, privacy, and hot fomentation to the suprapubic region. If all of these fail, catheterize the bladder as a last step.

Abdominal distension:

• This is not common. It can happen when large intestinal contents of the hernia sac are reduced or handled as in scrotal hernias or sliding hernias.
• It is also important to realize that the omentum is attached to the stomach and colon above. One should see that bleeders from injured arteries of the omentum are ligated properly.
• Some intraperitoneal blood may add to paralytic ileus.

3. Intermediate—between 3 and 7 days

• Seroma is due to an inflammatory response to mesh or suture materials. It causes swelling and anxiety that it may be a recurrence. When in doubt, get an ultrasound examination first. Seroma needs to be aspirateSeroma is more common after laparoscopic hernia repairs.

Surgical site infection:

• Hernia is a clean surgery. Infection should not occur. However, poor handling of the tissues, hematoma, seroma, and diabetes may precipitate wound infection.
• Patients with skin disease or co-morbid factors are given an injection of cefazolin 1–2 g intravenously 30 minutes before the incision or clindamycin if the patient is allergic to cefazolin.
• If infection is suspected, open the sutures, drain the pus, and use appropriate antibiotics. Persistent wound infection may prompt the removal of the mesh. A few cases of tuberculosis have been reported this is due to improper sterilization of the mesh used.

Late: Late complications are not all that common. One complication that bothers a few patients is chronic pain called inguinodyni is seen in about 10% of post-hernioplasty pain. It is defined as persisting pain more than 3 months after surgery.

Inguinodynia:

• The chief factor is an injury to the following nerves: Iliohypogastric, ilioinguinal, and genital branch of the genitofemoral nerve.
• Injury can be in the form of entrapment of the nerves, traction injury, cauterization, or transaction, These are more common after mesh repair because of entrapment of the nerves or perineural fibrosis and adhesions between the mesh and the nerves.
• Clinical features include dull aching or dragging pain in the groin, genitalia, and suprapubic region.
• Some may complain of diminished sensation or even hyperaesthesia Treatment usually includes reassurance, simple analgesics, nerve blocks with anesthetic agents, and injection of steroids.
• Neurolysis by inguinal exploration or neurectomy may be required in appropriate cases.

Ischaemic orchitis and testicular atrophy

• It occurs due to thrombosis of veins of the pampiniform plexus within the spermatic cord and is more common in direct hernias where handling of the spermatic cord while separating it from the long-standing sac may result in thrombosis.
• It can also be due to injury to the testicular artery.
• Venous congestion results in ischaemic orchitis causing pain in the testis.
• It is treated with anti-inflammatory drugs.
• Ischaemic orchitis is more common after recurrent hernia surgeries.