Surgery – Instruments – Cyrogenic application
Patent
1994-09-22
1997-09-16
Sykes, Angela D.
Surgery
Instruments
Cyrogenic application
606 20, 606 22, 606 25, A61B 1736
Patent
active
056675054
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The invention concerns the method of carrying out cryosurgical interventions based on the destruction of the pathological tissue consisting of freezing the biological tissue below -25.degree. C. with its subsequent rewarming up to the body temperature and the device for carrying out this method consisting of operating apparatus with a built in container of cooling medium and operating instrument and control unit.
BACKGROUND OF THE INVENTION
In the destruction of the pathological tissue by the local deep undercooling for the therapeutic treatment of benign as well as malignant tumors in the proctology, gynecology, oncological surgery, etc., the biological tissue has been yet exposed to the action of low temperature below -25.degree. C. After that, the biological tissue is rewarmed up to the initial body temperature. In the still known methods rapid freezing with subsequent rewarming up at a comparable speed is performed.
The disadvantage of this known procedure is particularly a too high speed when rewarming the tissue up to the initial temperature. For achieving a reliable cryodestruction, in the literature, as well as in accordance with experience in practice rapid cooling is recommended down to temperatures below -25.degree. C. at a rate of about 200 K/min or above with a subsequent moderate rewarming up to the body temperature at a rate of 10 to 20 K/min. With respect to the necessary rewarming rate, the whole operation would be very time consuming and this approach is not feasible with respect to the fact that the intervention calls for a high degree of the concentration.
For the methods mentioned, devices have been yet known consisting of an operation apparatus with a built in container of the cooling medium, most typically liquid nitrogen. To the operation apparatus, an operation instrument is attached having at its end a heat exchanger or applicator arranged for fitting operating tips.
This device makes possible only rapid cooling and comparably rapid rewarming of the tissue. Thus, the drawback is in the impossibility of a suitable continuous control of the cooling and particularly rewarming rates. The temperature control is implemented by the maximum rate given by the heating power of relevant heat exchangers of the operating apparatus and by their instantaneous thermal load. A further disadvantage is in the impossibility of checking proper fitting of tips to the operation instrument and thus also the impossibility of checking the necessary contact between the operation tip and tissue. The impossibility is also disadvantageous of the preliminary determination of the cooling power in the still existing devices.
SUMMARY OF THE INVENTION
The above mentioned disadvantages are to a considerable extent avoided by a method of performing the cryosurgical intervention consisting of cooling the biological tissue below -25.degree. C. with its subsequent rewarming to the body temperature in accordance with the invention. Its principle is in that the contact area of the biological tissue is cooled down at a rate of at least 180 K/min to -190.degree. to -160.degree. C., after that it is rewarmed at a rate of 100 to 240 K/min to -70.degree. to -20.degree. C. Then the contact area of the biological tissue is rewarmed at a rate of 10 to 25 K/min to -5.degree. to +5.degree. C. with a subsequent continuation of the rewarming procedure up to the body temperature. A considerable advantage of this method is that the total time of the controlled rewarming procedure is shorter than 5 min, which can be provided.
For perfoming the described method it is suitable to use the device consisting of an operation apparatus with a built in container of the cooling medium and operation instrument, and of the controlling unit in accordance with the invention. Its principle is that the control unit is formed by a controlling microprocessor coupled to electronic switches of an electromagnetic valve of heat exchanger, a heater of the heat exchanger, an additional heater of outlet gases and an additional heater of
REFERENCES:
patent: 3439680 (1969-04-01), Thomas, Jr.
patent: 4345598 (1982-08-01), Zobac et al.
patent: 4860744 (1989-08-01), Johnson et al.
patent: 5139496 (1992-08-01), Hed
patent: 5207674 (1993-05-01), Hamilton
patent: 5334181 (1994-08-01), Rubinsky et al.
Peffley Michael
SMT spol. s.r.o.
Sykes Angela D.
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