Peri- and postoperative pain valutation in carpal tunnel release of median nerve compression.

We analysed 108 patients, operated on day surgery, for carpal tunnel release of median nerve compression, to evaluate peri- and postoperative pain. We made in all cases a short intertenarian incision (25 mm) with microsurgical technique and local anaesthesia using mepivacaine 2% without vasoconstrictor. We evaluated pain for local anaesthetic infiltration as VRS (Verbal Rating Scale) 6,3 median-time to the first possible analgesic assumption (in all cases paracetamol 500 mg), total analgesic assumption, pressure algometry (to evaluate "allodiny") after the first 48 hours and subjective pain intensity by a numerical pain scale. Pain intensity on first drug assumption (after a mean time of 7 hours from the end of surgery) had a mean VAS value of 2,15; while after a second assumption of analgesic (after a mean time of 15 hours from surgery) had a mean VAS value of 2. Mean total analgesic assumption was 1,64 tablets of paracetamol 500 mg. From these data we may deduce that peri- and postoperative pain following median nerve decompression with this technique and anaesthesia, has a moderate intense peak of brief duration, for local anaesthetic infiltration (that seems to be the most painful event) and modest and not constant pain in the postoperative time (more evident 7 and 15 hours from the end of surgery). It may be useful association with mepivacaine bicarbonate solutions or injecting less painful local anaesthetic.

Ultrasonic aspiration in the surgical treatment of intracranial tumors.

The CUSATM (Cavitron Corporation - Stamford, Conn., USA) has been used for aspiration and ultrasonic fragmentation in 52 cases of intracranial tumors: 24 meningiomas, 20 gliomas, 5 acoustic neurinomas, 1 cerebral metastasis, 1 pinealoma, 1 pituitary adenoma in our Clinic, since January 1979. Several advantages of the CUSA were found as compared to conventional techniques: it provides good visibility of the operating field: pathologic tissue can be removed from the surface to the deep structures and only one instrument is present in the surgical cavity; its use reduces manipulation, traction and thermic effects on nearby tissue; it selectively spares major vessels and has a hemostatic effect on those less than 1 mm in diameter. The rapidity of the action of the CUSA is relative to the consistency of the tissue. Tumors of high consistency are very slowly removed by the CUSA, and its use is not worthwhile. In our cases no damage to the surrounding structures was evident. Preliminary experimental data suggest that the use of the CUSA be avoided near the brain stem or within the spinal cord. However, in a cervical ependymoma of our series, the CUSA provided complete removal of the mass without complications. This result was achieved by using lower vibratory power: we were thus able to remove pathologic soft tissue without clinically evident damage to the surrounding structures. In some particular situations the volume and the shape of the instrument can be a hindrance, and some modifications are suggested: a bayonet shape and longer tip would facilitate the reaching of deep structures and permit its use in transphenoidal surgery; incorporation of a cautery in the tip, so that contemporary hemostasis can be accomplished. Our experience indicates that the use in transphenoidal surgery; incorporation of a cautery in the tip, so that contemporary hemostasis can be accomplished. Our experience indicates that the use of the CUSA is better indicated in deep tumors: meningiomas of the base of the skull, acoustic neurinomas, pinealomas, pituitary adenomas. In gliomas it is very useful in the selective removal of the neoplastic tissue in functionally important areas.