Complex incisional abdominal hernias including those arising as a result of failed, or infected abdominal operations. How these hernias are treated by the multidisciplinary abdominal team.
- What is an incisional hernia?
- What is the treatment for abdominal incisional hernias?
- What happens following surgery?
After an abdominal operation, the tissues that comprise the abdominal wall may not heal correctly and this can result in an ‘incisional hernia’. All such hernias are complex given that patients will have had previous surgery and many may be elderly, obese or have significant co-mordities e.g. heart or lung disease.
As an ageing, often obese, population undergoes increasingly complicated operations, complex hernia units are being faced with increasingly challenging incisional hernias. A large number of such cases will have developed wound infections post-operatively, some sadly with MRSA, and this may have contributed to the hernia formation. Unfortunately this infection history places the patient at higher than usual risk of further infections.
Unfortunately the reported outcome for the repair of incisional hernias is extremely variable and this has led to the evolution of complex hernia units. Such units usually consist of both general (bowel and abdominal) and plastic/reconstructive surgeons working together. These operations are then performed in institutions with access to ‘state of the art’ facilities which are required for the more complex cases. This team concept is important given that the challenges of repairing complex incisional hernias involves reconstructing the intra-abdominal and extra-abdominal compartments.
Previously failed repairs?
Many patients will have had previous repairs which have failed, often with plastic mesh in situ. The combination of an increasingly scarred intra-abdominal space, often with plastic mesh stuck to the intestines, and unhealthy soft tissue outside the intra-abdominal space means such patients need expert care.
Often these patients are significantly overweight and this adds an additional level of risk given that the tissue in the abdominal wall is both large and heals poorly.
As surgeons have become aware of the nuances of managing such complicated cases, the techniques employed have evolved in parallel with the ‘team’ approach.
The planning starts in the outpatient setting with a careful evaluation of the patient and the hernia. It is important to understand the chronology of the events that have led to the current hernia so the team can decide the best operative approach.
Determining the extent of the defect
Only in the most unfit patients will a non-operative option be considered which is usually a custom-made corset to provide support.
The patient’s hernia is usually photographed to provide an objective documentation of the challenge and this is then combined with cross sectional imaging of the abdomen with either MRI or CT. Imaging allows the extent of the defect to be determined and the involvement of the underlying bowel to be appraised.
All incisional hernias are repaired using mesh and in the most complex cases this is usually of the ‘biological’ variety. Biological mesh is derived from animal tissue and is far more resistant to infection and ultimately becomes incorporated into the patient’s own tissues. Unfortunately these meshes are very expensive and need to be justified on a case by case basis.
Once the patient has been reviewed by the ‘hernia team’ the operation is planned and the patient assessed for fitness by the anaesthetists and intensive care unit.
Ensuring medical care is optimised in advance of surgery is as important as the operative technique in ensuring excellent outcomes.
The operation commences with the removal of all unhealthy tissue in the abdominal wall. This may then require formal reconstruction by a plastic/reconstructive surgeon once the mesh has been inserted and the muscle layers repaired.
This soft tissue reconstruction is akin to a ‘tummy tuck’ operation but is not performed for cosmetic reasons but rather to ensure healthy wound healing of the soft tissues.
By only using healthy tissue in the repair this reduces post-operative wound complications.
The intestines are then returned to the abdominal cavity which is often a lengthy procedure as many patients will have undergone previous complex bowel operations. The ‘complex hernia unit’ always includes a senior bowel surgeon, who often leads the team.
The mesh is then usually placed behind the muscles of the abdominal wall secured in place with sutures and the muscles closed over the top.
In some circumstances the muscles will have split so far apart that advanced techniques will need to be applied to allow them to be re-approximated (so-called component separation).
In the most severe cases even component separation is not sufficient to permit the muscles to return to the midline with the repair based wholly on the mesh which is used to ‘bridge‘ the defect.
At the end of the procedure drains are left to try to prevent the accumulation of fluid in the wound in the post-operative period and may stay in situ for some days.
The patients require the care of a number of different health care professionals in the post-operative phase including intensive care doctors, the surgical hernia team and specialist wound care nurses.
The published outcomes from specialist units who routinely treat complex incisional hernias demonstrate that the ‘team’ approach combined with modern techniques and state of the art technology translates into improved outcomes.
Sadly the recurrence rates for incisional hernia repair are still significant but the best chance of success is to provide the best repair from the first presentation of the hernia.