[Technical principles of prostatic cryosurgery (Part 1)].

OBJECTIVES

Cryosurgery is defined as in situ freezing of tissues. Criosurgery in the treatment of prostate cancer aims to: 1- Eliminate all the glandular tissues and completely destroy the adenocarcinoma, 2- With a minimum number of complications. a) Preserving neighbour structures: bladder neck, striated sphincter, and rectum. b) Preserving urethral mucosa to reduce the elimination of sloughing tissues.

METHODS

We describe the technique of prostatic cryosurgery including all innovations introduced during the last ten years. The map with the number and situation of the 6-8 crioprobes should be done in such a way that the iceball created around each of them overlaps the contiguous ones. Probe-mapping and icing strategy together get the prostate included in a unique, solid mass, in which temperature descents homogeneously and spreads out of its limits, so that intraprostatic and extraprostatic temperatures (sensors at the apex, Denonvilliers fascia and both neurovascular bundles) are below -40 degrees C.

RESULTS

The standardized technique is based on: Substitution of liquid nitrogen by argon. Use of 6 to 8 cryoprobes. The probes are properly inserted into the perineum percutaneously under transrectal ultrasound guidance. Ice ball evolution control by biplane transrectal ultrasound. Separation of the two layers of Denonvilliers' fascia by injection of saline solution. Real-time measurement of temperature descent. Minimal temperature lower than -40 degrees C Commercial ureteral heating system. Double cycle of freezing-unfreezing Administration of hormonal therapy during time enough to avoid the gland size to exceed 45-50 cc.

CONCLUSIONS

We describe the most advanced technique for prostatic freezing, highlighting the basic requirements to achieve the objectives pursued. It has improved oncologic results, in relation to PSA and percentage of negative biopsies, and has dramatically reduced complications.