Clinical classification of inguinal hernias
Clinically inguinal hernias can be further sub-classified into the following groups relating to whether the inguinal hernia can be reduced or whether their are complications:
Reducible:
The contents of the hernia can be reduced by applying pressure |
Irreducible or incarcerated:
The contents of the hernia sac cannot be reduced and its contents have become adhered but its blood supply has not been compromised |
An incarcerated hernia can develop into a strangulated hernia, which frequently involves strangulation of the small intestine and often the omentum but rarely the large instestine or other viscera. Subsequently the blood supply of the contents of the hernia is compromised causing ischaemia.
Other classifications include the contents themselves and are grouped into Maydl’s, Richter’s and Littre’s hernias:
Maydl’s:
The hernial sac contains two loops of the small intestine where by the loop in the abdominal cavity may become strangulated or obstructed. |
Richter’s:
Part of the circumference of the intestine’s antimesenteric border protrudes through and/or is strangulated through a defect in the abdominal wall. |
Littre’s:
The protrusion of a Meckel diverticulum (a congenital diverticulum of small intestine) through an abdominal opening. |
However, these many factors are variable and inadequate for managing and understaning the complex pathophysiology of inguinal hernias. Subsequently a standardization of these factors is being used for classification, which is important for the surgeon in deciding which type of hernia repair may be best for each individual patient. However these classifications are continually being modified to reflect the developments in hernia surgery.
Numerous classifications for inguinal hernias have been described and proposed to allow surgeons to define the anatomical type of hernia and to match the repair to the defect found. Some of these classifications include Casten (1967), Halverson and McVay (1970), Gilbert (1989), Nyhus (1991), Bendavid (1993), Aachen, also known as the Schumpelick-Arit (1995), Rutkow and Robbins (1998), Zollinger (2003). These systems are based on the size of the hernia and the status of the posterior floor and/or the deep inguinal ring to describe the hernia, with the most popular of these classifications including:
Halverson and McVay (1970)
Nyhus (1991)
Gilbert (1989)
Aachen, also known as the Schumpelick-Arit (1995)
Nyhus (1991)
Gilbert (1989)
Aachen, also known as the Schumpelick-Arit (1995)
However the most widely accepted by surgeons is the Nyhus (1991) classification, which is used to determine which type of repair is most suitable.
Although these scheme for classifying hernias is underway, there is no one uniform classification method which is currently being used (2008) but in a recent survey the most common of these classifications used by the American and European hernia society are those of Nyhus (1991), Gilbert (1989) and Aachen, also known as the Schumpelick-Arit (1995).