PROSTATE CRYOSURGERY TECHNIQUESeptember 1996
The access to the prostate is percutaneous, transperineal, transrectally US.-guided. The probes (from 5 to 7 probes must be used) are inserted in the gland and, if necessary, also near it so as to allow the modelling of an ice-ball covering the whole gland, the surrounding area of the seminal vesicles, the apex and any suspect area (which will be singled-out in the afore-mentioned pre-surgical study) with an isotherm-curve of at least -20°C. It is of absolute importance not to damage the trigonus, the rectum, the pubic symphisis, the perineal plane: it may cost serious complications.
The thermocouples are inserted in the selected points (at least 5), so as to be able to reach or avoid reaching certain temperatures.
Now the urethral warmer is applied; it will convey a heated solution to try to avoid damages to the urethra.
The cryoprobes are switched on for two freezing-cycles alternated by a complete thaw. (cell-death is subject to statistics, therefore a second freeze will increase the possibilities of a sufficient damage being caused to all tumorous cells. Moreover, the functional and metabolic damage caused by the first freeze-cycle sharpens the tissue-freezing power of the second one which can therefore be considered as more cyto-destructive). If necessary , should the apical freezing not have been completed over the 1st phase, the probes may, in the 2nd phase, be withdrawn by 1 cm.
Now, probes and thermocouples may be removed and the small perforations stitched.
The urethral warmer is the last part to be removed. In this way the urethra will be protected from damage for a greater period.
A cystostomy or a catheter, or both, will be applied for a period varying from 6 days to 6 weeks. The duration of the cystostomy does not only depend on the return to spontaneous micturition but also on the period of time you wish to give to the urethra to heal (catheterization prevents the urethra from undergoing the stress derived from the mechanical flow of micturition, thus avoiding damages when the walls are most fragile).