The use of mesh in hernia repair, risk management and the advantages of day surgery - 
Part 2 - Hernia Repair under Local anaesthesia

3.                  Skin and Subcutaneous tissue infiltration

 The skin is infiltrated along the site of the proposed incision. Epidermal injection rather than into the subcutaneous fat gives a rapid onset of action. It tends to sting a little more initially. The subcutaneous fat is then infiltrated. The local anaesthetic can be infiltrated deep to the external oblique before any incision is made. Should this be done, one must aspirate first to ensure the local anaesthetic is not injected in a bolus into vein. As the needle penetrates through the external oblique a giving sensation is experienced. This layer can be anaesthetised under direct vision following division of the subcutaneous fat. The superficial vessels are then ligated to give tome for the local anaesthetic to take effect.

After the external oblique is divided, further local anaesthetic can be administered into specific sites.

In dealing with the sac, gentle technique avoids local and referred pain into the scrotum, testis or intra-abdominally. Occasionally some vaso-vagal effect is noted with the slowing of the pulse and a fall in the blood pressure if excessive traction is applied.  More local anaesthetic is used if there is pain. Atropine 1.2 mg I/V, or intravenous fluid are used to counteract the vaso-vagal effects if these are severe or prolonged.

The contents can usually be dealt with under local anaesthetic

During the procedure the patient is relaxed and there is no obvious muscular tension making surgery difficult.

The patient can cough or strain to demonstrate the protrusion of the hernia. Following removal of the sac further coughing demonstrates the efficiency of this. The tension on the sutures and adequacy of repair can be tested.

Other herniae can be repaired using local anaesthetic.

The uncomplicated femoral hernia repair (from below the inguinal ligament) is ideally suited to repair under local anesthetic. Small, epigastric para-umbilical and umbilical hernia can be repaired using the same agents and similar infiltration technique.

Conclusion

Hernia repair using local anaesthetic and sedation is a very effective method of anaesthesia for hernia repair in experienced hands. Each surgeon and anaesthetist will use different degrees of sedation. It should however be remembered that analgesia is not achieved by sedation, but by correct use of local anaesthetic and a gentle technique.