Incisional Hernia
Incisional hernia results from a failure of fascial tissues to heal and close.
Risk factors:
Sutures-
Methods of closure-
Suture to wound length ratio-
Acute wound failure (dehiscence)-
Techniques of repair:
The Onlay Technique-
The following technique of onlay implantation is followed. The skin scar is excised. The hernia sac is then dissected to expose the fascial edges.
The sac is then opened, gut adhesions identified and detached. The abdomen is inspected to look for additional fascial gaps.
The fascial edges are then apposed and closed using non-absorbable suture.
The prosthetic material is then sutured to the fascia with a distance of at least 5cm from the suture line.
A non-absorbable circular suture should be used.
One or two suction drains are used to drain the collection. It is advisable to put subcutaneous sutures to burry the prosthesis before closing the skin.
The main disadvantage of the onlay technique is the direct contact of the prosthesis with the environment if the wound becomes infected and needs wound revision.
The Sublay Technique-
An alternative to the onlay technique is the subfascial or preperitoneal implantation of prosthetic material (Sublay Technique).
The steps include the excision of the skin scar followed by the dissection of the hernial sac. Sufficient abdominal wall is then mobilized. The sac is opened and adhesions removed.
The prosthetic material can be implanted preperitoneally or after closing the peritoneum, prefascially, using non absorbable sutures.
The mesh should cover the gap and extend at least 5cm beyond the gap.
The anterior rectus sheath is then incised 4cm from the medial edge and is then reflected inwards and the frontal fascia is then closed.
One or two suction drains are then inserted. The subcutaneous layer is closed before applying skin sutures.
Components' Separation Technique-
This operation devised by Ramirez & colleagues allows a flap of the rectus muscle, anterior rectus sheath & internal oblique & transversus to be advanced in the midline.
The external oblique is released from its attachment to the rectus muscle and a plane dissected between the external & internal oblique aponeurosis.
An additional step is the complete release of the rectus abdominis muscle from its anterior and posterior sheaths by incising the posterior rectus sheath at its medial border- the so called sliding door technique.
This technique allows the tensionless approximation of the rectus muscles.
Many surgeons recommend the additional application of synthetic mesh in an onlay position to supplement the attenuated layers of the anterior abdominal wall.