The use of mesh in hernia repair, risk management and the advantages of day surgery

Chronic Irreducibility

These are not usually as painful or tender. Abdominal pain is not a feature. Emergency surgery is not necessary, although a chronically irreducible hernia may still become strangulated. Herniae are a very common problem and while they can cause abdominal pain, the possibility of a co-existent lesion in the bowel, such as a carcinoma of a colon, particularly in the elderly, must always be borne in mind.  

PRACTICAL MANAGEMENT – OF A POTENTIALLY STRANGULATED HERNIA

In early cases, gentle manipulation or “taxes,” to reduce the hernia may be attempted – whilst the patient is recumbent with the foot of the bed elevated.

When analgesics are given the hernia sometimes reduces spontaneously because the ring and surrounding muscles are relaxed. Similarly in the theatre the hernia reduces on induction of the anaesthetic. This suggests that the process is not so advanced and at operation the contents will be found to be viable.

At operation the contents should be controlled so that they do not slip back and can be inspected to determine whether resection is necessary. Should the contents slip back before inspection, a laparotomy may be necessary. In addition the infected or gangrenous contents can contaminate the abdominal cavity.

With strangulated hernias it is sometimes difficult to be sure which layer is the sac during dissection. The bloodstained fluid within the sac can look like bowel. The fluid layer reduces the risk of damage to the bowel as the sac is opened. Once the sac is opened the contents can be inspected and grasped gently while the ring is divided. With a tight ring there is a danger of damage to the bowel whilst dissecting. This must be avoided by careful and gentle dissection.  Then the contents are delivered further into the wound, and in the case of bowel, both the proximal and the distal limb as well as the site of constriction must be inspected to ensure they are viable.

In Summary

The terms obstructed or incarcerated are used to describe an acutely irreducible hernia at an early stage. It implies that the process may proceed to strangulation, but these changes have not yet occurred. Rapid progress to overt strangulation with necrosis followed by perforation and peritonitis may occur.

Should an acutely irreducible hernia reduce spontaneously and immediate surgery not be arranged, a close clinical watch must be instituted for irreversible damage may nevertheless occurred.

The symptoms and signs of the development of strangulation can be masked particularly in :

A.  Infants
B.  The elderly or frail
C.  Those who have been given a narcotic agent for the relief of pain and D.  The obese.

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A close clinical watch is instituted if uncertain. Surgical action is preferred rather than excessive delay.

TERMINOLOGY

Obstructed, Incarcerated and Strangulated
These clinical terms are used to describe events associated with an acutely tender irreducible hernia. These terms suggest the blood supply is occluded and the delay will result in ischaemia, necrosis and gangrene.

While obstruction and incarceration suggest the sequence is less advanced than strangulation, clinical differentiation is difficult and demands surgical exploration.

Any acutely painful irreducible hernia should be considered strangulated and treated by surgery.

The sequence of events are best related to the findings at operation.

Pathology
Initially the omentum or loop or bowel with its mesentery are trapped at the tight ring (imprisoned or incarcerated). Lymphatic obstruction results in an oedematous appearance and serous fluid is found in the sac.

With venous obstruction, bruising and ecchymoses develop and extend. The fluid in the sac becomes increasingly blood-stained.

With persistent complete arterial blockage, the omentum or the loop of bowel, superimposed on previous widespread ecchymoses,  becomes plum-coloured and then black because of anoxia. The fluid becomes heavily blood-stained and foul smelling, with bacterial invasion.

The site at which the contents are constricted is often more severely affected – “constriction rings: are formed. When the obstruction is released at a later stage no blood oozes from the surface of the bowel or at the site of the constriction rings and the normal colour does not return. Arterial pulsation and peristalsis in the bowel do not reappear.

OVERVIEW

Hernia surgery is changing rapidly since the introduction of the routine use of mesh and laparoscopic surgery.

About 10 years ago laparoscopic surgery was introduced and proved an immediate boom for gallstone sufferers. Some of the early patients developed major complications but this has now settled with experience at acceptable levels.

Following these developments laparoscopic hernia repair developed an impetus and went through a very expansive period, which has now settled back in many countries. In some 15% of cases were carried out laparoscopically by what has been termed key hole surgery, but this has now been reduced to about 7% of cases. This will be discussed in future articles where various methods are compared and as these evolve.