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A Cryogenic Probe for Intravitreal Surgery*
N O T E S , CASES, INSTRUMENTS A CRYOGENIC PROBE FOR INTRAVITREAL SURGERY* A PRELIMINARY REPORT P A U L A.
OBIS,
M.D.
St. Louis, Missouri In 1962, Cooper, Grissmann, and Johnston 1 developed a complete system for cryogenic surgery, employing liquid nitrogen as a coolant and vacuum insulation for protection of all tissues except those being surgically treated. T h e system^ produced for this purpose is shown in Figure 1. In 1963, Lincoff, McLean and N a n o 2 adapted this system for episcleral and transconjunctival treatment of retinal detachment, thus reviving a technique which Bietti 3 had suggested in 1933. It is the purpose of this preliminary report to describe a cannula (fig. 2) which has been designed specifically for use in intravitreal surgery. In essence, this cannula is a modification of the smallest probe employed by Cooper and his coworkers in brain sur* From the Department of Ophthalmology and the Oscar Johnson Institute, Washington University School of Medicine. This research was supported in part by grant B-1789 from the National Institute of Neurological Diseases and Blindness of the National Institutes of Health, Public Health Service. t The Linde Corporation Laboratory, Indianapolis, Indiana.
gery. T h e dimension and properties of this modified instrument are listed in Table 1. T h e construction diagram is shown in Figu r e 3. In order to reduce the size of the cannula from 2.2-mm to 1.5-mm diameter, the warm-up system had to be omitted. T h e properties of the instrument otherwise are in principle the same as specified in the instruction sheet F-2238 issued by the Union Carbide Corporation (see legend fig. 3) for Cooper's probe. A t a temperature of — 40°C constantly maintained at the probe tip, the ice-ball formed in the vitreous of an autopsy eye hardly reaches 5 mm in diameter within 10 to 15 seconds. T h e warm-up time required for the complete thawing of this ice crust is about the same. T h e freezing effect can be limited just to the tip of the probe by intermittent cooling. According to Cooper, 4 freezing causes (1) cellular destruction by hydration and concentration of electrolytes due to removal of water from solutions, ( 2 ) crystallization with rupture of cellular membranes, ( 3 ) denaturation of liquid protein molecules within the cell membrane, ( 4 ) thermal shock and ( 5 ) vascular stasis. Hence, the cryogenic technique should not be employed in eyes with normal vitreous structure.
Fig. 1 (Cibis). Complete system for ophthalmic cryosurgery (Linde CE-3). ( A and B) Electronic control console. (C) Foot switch. ( D ) Container for vacuum-insulated ophthalmic cryosurgical probe ( a r r o w ) . ( E ) Nitrogen-oxide gas container with pressure control
916
NOTES, CASES, INSTRUMENTS
917 TABLE 1 SPECIFICATIONS
Electronic control console Width 19 inches Height 13 inches Depth 17 inches Operating pressure 15 psi Voltage 110 v Probe Length 27 mm Diameter 1.5 mm Tip diameter 1.5 mm Response rate Up-sclae 10° C/sec Down-scale 10°C/sec Temperature range +37°C to -100°C
Fig. 2 (Cibis). Vacuum-insulated cryogenic probes used in ophthalmic surgery. (A) Probe of Lincoff et al2 designed for episcleral applications of cold. (B) New probe designed for use in intravitreal surgery. Indications for the use of intravitreal cryosurgery are : ( 1 ) removal of nonmagnetic foreign bodies from the vitreous cavity, (2) separation of epiretinal fibroplastic tissue organizations from the retina, ( 3 ) transvitreal treatment of small retinal holes, neovascularizations, neoplasms and rolledover retinas, and ( 4 ) removal of selected samples of "vitreous" or of pathologic
Probe handle Length 15 cm Diameter 3.2 cm Filling time: 2-5 min tissue from the vitreous cavity for histologie examination. Details of the various procedures currently used and the results achieved with these techniques will form the basis of subsequent reports. 660 South Euclid Avenue
(63110).
DIA6RAMATIC REPRESENTATION OF FREEZING PROBE FOR INTRAOCULAR SURGERY -LIQUID NITROGEN FILL Θ PRESSURE RELIEF PORT
N,
PRESSURE ( 30 PSI )
\
GASEOUS N? VENT _WARMIN6_CqiL_LE_A0S_ .. . . Γ THERMOCOUPLE LEADS" I l H ί' ι f VACUUMI INSULATED LIQUID NITROGEN RECORDER CONTAINER CONTROLLER
|
VENT £u I
I
\ I
^HANDLE) VACUUM"INSULATED PROBE ^FREEZING TIP
I VACUUM INSULATION 8 -THERMOCOUPLE LEADS— COLO GAS CONDUIT-—' — * A R M GAS CONDUIT ' ENLARGED VIEW
LATERAL SECTION
-EXTERNAL PRESSURE SOURCE
Fig. 3 (Cibis). Diagram of complete system used in intravitreal surgery (modification of diagram produced by Union Carbide Medical Products for Linde CE-3 apparatus).
918
NOTES, CASES, INSTRUMENTS REFERENCES
1. Cooper, I. S., Grissman, F., and Tohnston, P.: A complete system for cryogenic surgery. St. Barnabas Med. Bull., 1:11-16, 1962. 2. Lincoff, H. A., McLean, J. M., and Nano, H. : Cryosurgical treatment of retinal detachment. Tr. Am. Acad. Ophth., 68:412, 1904. 3. Bietti, G. B. : Richerche sulle variazione di temperatura di alcune zone del bulbo oculare per diatermocoagulazioni episclerali, termocauterizzazioni e criocausticazione : Contributo allo studio dell'insorgenza di una cataratta nelle operaziom contro il distacco retinico. Boll. Oculist, 12:1427-1457 (Dec.) 1933. 4. Cooper, I. S.: Cryobiology as reviewed by the surgeon. Cryobiology, 1:44-51, 1964.
FOR A
A COMBINED OPERATION CATARACT AND GLAUCOMA SIMPLE,
ADAPTABLE,
TWO-STAGE
PROCEDURE FOR ONE OPERATION F. H.
NEWTON,
M.D.
Dallas, Texas T h e growing interest in one-stage operations for multiple intraocular conditions justifies a consideration of methods. F o r combined cataract and glaucoma a simple flexible procedure is offered, which may be especially helpful for beginners in this type of surgery. Very little additional trauma is added by the glaucoma phase of the operation. TECHNIQUE
A wide flap of conjunctiva and Tenon's capsule is dissected free to the limbus, narrowing its width as the 9- and 3-o'clock positions are approached. T h e usual cataract incision is made from the 10- to 2-o'clock positions and a radial corneoscleral suture of 6-0 plain gut is inserted at the 11- and 1-o'clock positions, respectively. T h e incision is extended to the 9- and 3-o'clock positions and an additional suture is placed at the 9:30- and 2:30-o'clock positions. A 7-0 silk suture is passed tangentially through the iris near the sphincter at the 12-o'clock position and the loose ends are laid aside on moist gauze with no forceps attached. T h e kind of closing suture material used is, of course, optional. W i t h the iris undisturbed and the pupil dilated, the lens is removed, preferably in the capsule, and the four sutures are tied,
leaving open the 11- to 1-o'clock space. If a tighter wound closure is desired, a third suture may be added on each side. Removal of the lens before the iris is disturbed minimizes trauma to iris tissue. No preformed iris pillar or pillars are in the way and the iris diaphram helps hold back the vitreous. Preformed iris pillars are those made prior to delivery of the lens. W i t h iris intact, lens removed, the wound closed except from the 11- to 1-o'clock positions, the operator has the situation under control and can decide with a feeling of security whether or not to proceed with the operation for glaucoma. If surgery for the glaucoma is advisable, a variety of procedures are available (one peripheral iridectomy with sclerectomy, [Scheie] ; sector iridectomy without iris inclusion, sector iridectomy with sclerectocleisis [Hughes, Birge] ; iridencleisis with two pillars with or without sclerectomy; inclusion of a rectangular section of iris [Wenaas and Stertzbach], etc). No one method fits all cases. The surgeon may choose one of several methods of doing the sclerectomy but some form of sclerectomy must be done. Since the lens is removed before the iris is disturbed, the handling of the iris is made much easier, safer and less traumatic by using the single silk suture, previously described, to draw the iris through the wound in any kind of iris inclusion operation or sector iridectomy. At this stage, the wound is closed except from the 11- to 1-o'clock positions. The iris suture eliminates the necessity of reaching in with forceps to grasp the iris unsupported by the lens. T h i s re-
OBIS,
M.D.
St. Louis, Missouri In 1962, Cooper, Grissmann, and Johnston 1 developed a complete system for cryogenic surgery, employing liquid nitrogen as a coolant and vacuum insulation for protection of all tissues except those being surgically treated. T h e system^ produced for this purpose is shown in Figure 1. In 1963, Lincoff, McLean and N a n o 2 adapted this system for episcleral and transconjunctival treatment of retinal detachment, thus reviving a technique which Bietti 3 had suggested in 1933. It is the purpose of this preliminary report to describe a cannula (fig. 2) which has been designed specifically for use in intravitreal surgery. In essence, this cannula is a modification of the smallest probe employed by Cooper and his coworkers in brain sur* From the Department of Ophthalmology and the Oscar Johnson Institute, Washington University School of Medicine. This research was supported in part by grant B-1789 from the National Institute of Neurological Diseases and Blindness of the National Institutes of Health, Public Health Service. t The Linde Corporation Laboratory, Indianapolis, Indiana.
gery. T h e dimension and properties of this modified instrument are listed in Table 1. T h e construction diagram is shown in Figu r e 3. In order to reduce the size of the cannula from 2.2-mm to 1.5-mm diameter, the warm-up system had to be omitted. T h e properties of the instrument otherwise are in principle the same as specified in the instruction sheet F-2238 issued by the Union Carbide Corporation (see legend fig. 3) for Cooper's probe. A t a temperature of — 40°C constantly maintained at the probe tip, the ice-ball formed in the vitreous of an autopsy eye hardly reaches 5 mm in diameter within 10 to 15 seconds. T h e warm-up time required for the complete thawing of this ice crust is about the same. T h e freezing effect can be limited just to the tip of the probe by intermittent cooling. According to Cooper, 4 freezing causes (1) cellular destruction by hydration and concentration of electrolytes due to removal of water from solutions, ( 2 ) crystallization with rupture of cellular membranes, ( 3 ) denaturation of liquid protein molecules within the cell membrane, ( 4 ) thermal shock and ( 5 ) vascular stasis. Hence, the cryogenic technique should not be employed in eyes with normal vitreous structure.
Fig. 1 (Cibis). Complete system for ophthalmic cryosurgery (Linde CE-3). ( A and B) Electronic control console. (C) Foot switch. ( D ) Container for vacuum-insulated ophthalmic cryosurgical probe ( a r r o w ) . ( E ) Nitrogen-oxide gas container with pressure control
916
NOTES, CASES, INSTRUMENTS
917 TABLE 1 SPECIFICATIONS
Electronic control console Width 19 inches Height 13 inches Depth 17 inches Operating pressure 15 psi Voltage 110 v Probe Length 27 mm Diameter 1.5 mm Tip diameter 1.5 mm Response rate Up-sclae 10° C/sec Down-scale 10°C/sec Temperature range +37°C to -100°C
Fig. 2 (Cibis). Vacuum-insulated cryogenic probes used in ophthalmic surgery. (A) Probe of Lincoff et al2 designed for episcleral applications of cold. (B) New probe designed for use in intravitreal surgery. Indications for the use of intravitreal cryosurgery are : ( 1 ) removal of nonmagnetic foreign bodies from the vitreous cavity, (2) separation of epiretinal fibroplastic tissue organizations from the retina, ( 3 ) transvitreal treatment of small retinal holes, neovascularizations, neoplasms and rolledover retinas, and ( 4 ) removal of selected samples of "vitreous" or of pathologic
Probe handle Length 15 cm Diameter 3.2 cm Filling time: 2-5 min tissue from the vitreous cavity for histologie examination. Details of the various procedures currently used and the results achieved with these techniques will form the basis of subsequent reports. 660 South Euclid Avenue
(63110).
DIA6RAMATIC REPRESENTATION OF FREEZING PROBE FOR INTRAOCULAR SURGERY -LIQUID NITROGEN FILL Θ PRESSURE RELIEF PORT
N,
PRESSURE ( 30 PSI )
\
GASEOUS N? VENT _WARMIN6_CqiL_LE_A0S_ .. . . Γ THERMOCOUPLE LEADS" I l H ί' ι f VACUUMI INSULATED LIQUID NITROGEN RECORDER CONTAINER CONTROLLER
|
VENT £u I
I
\ I
^HANDLE) VACUUM"INSULATED PROBE ^FREEZING TIP
I VACUUM INSULATION 8 -THERMOCOUPLE LEADS— COLO GAS CONDUIT-—' — * A R M GAS CONDUIT ' ENLARGED VIEW
LATERAL SECTION
-EXTERNAL PRESSURE SOURCE
Fig. 3 (Cibis). Diagram of complete system used in intravitreal surgery (modification of diagram produced by Union Carbide Medical Products for Linde CE-3 apparatus).
918
NOTES, CASES, INSTRUMENTS REFERENCES
1. Cooper, I. S., Grissman, F., and Tohnston, P.: A complete system for cryogenic surgery. St. Barnabas Med. Bull., 1:11-16, 1962. 2. Lincoff, H. A., McLean, J. M., and Nano, H. : Cryosurgical treatment of retinal detachment. Tr. Am. Acad. Ophth., 68:412, 1904. 3. Bietti, G. B. : Richerche sulle variazione di temperatura di alcune zone del bulbo oculare per diatermocoagulazioni episclerali, termocauterizzazioni e criocausticazione : Contributo allo studio dell'insorgenza di una cataratta nelle operaziom contro il distacco retinico. Boll. Oculist, 12:1427-1457 (Dec.) 1933. 4. Cooper, I. S.: Cryobiology as reviewed by the surgeon. Cryobiology, 1:44-51, 1964.
FOR A
A COMBINED OPERATION CATARACT AND GLAUCOMA SIMPLE,
ADAPTABLE,
TWO-STAGE
PROCEDURE FOR ONE OPERATION F. H.
NEWTON,
M.D.
Dallas, Texas T h e growing interest in one-stage operations for multiple intraocular conditions justifies a consideration of methods. F o r combined cataract and glaucoma a simple flexible procedure is offered, which may be especially helpful for beginners in this type of surgery. Very little additional trauma is added by the glaucoma phase of the operation. TECHNIQUE
A wide flap of conjunctiva and Tenon's capsule is dissected free to the limbus, narrowing its width as the 9- and 3-o'clock positions are approached. T h e usual cataract incision is made from the 10- to 2-o'clock positions and a radial corneoscleral suture of 6-0 plain gut is inserted at the 11- and 1-o'clock positions, respectively. T h e incision is extended to the 9- and 3-o'clock positions and an additional suture is placed at the 9:30- and 2:30-o'clock positions. A 7-0 silk suture is passed tangentially through the iris near the sphincter at the 12-o'clock position and the loose ends are laid aside on moist gauze with no forceps attached. T h e kind of closing suture material used is, of course, optional. W i t h the iris undisturbed and the pupil dilated, the lens is removed, preferably in the capsule, and the four sutures are tied,
leaving open the 11- to 1-o'clock space. If a tighter wound closure is desired, a third suture may be added on each side. Removal of the lens before the iris is disturbed minimizes trauma to iris tissue. No preformed iris pillar or pillars are in the way and the iris diaphram helps hold back the vitreous. Preformed iris pillars are those made prior to delivery of the lens. W i t h iris intact, lens removed, the wound closed except from the 11- to 1-o'clock positions, the operator has the situation under control and can decide with a feeling of security whether or not to proceed with the operation for glaucoma. If surgery for the glaucoma is advisable, a variety of procedures are available (one peripheral iridectomy with sclerectomy, [Scheie] ; sector iridectomy without iris inclusion, sector iridectomy with sclerectocleisis [Hughes, Birge] ; iridencleisis with two pillars with or without sclerectomy; inclusion of a rectangular section of iris [Wenaas and Stertzbach], etc). No one method fits all cases. The surgeon may choose one of several methods of doing the sclerectomy but some form of sclerectomy must be done. Since the lens is removed before the iris is disturbed, the handling of the iris is made much easier, safer and less traumatic by using the single silk suture, previously described, to draw the iris through the wound in any kind of iris inclusion operation or sector iridectomy. At this stage, the wound is closed except from the 11- to 1-o'clock positions. The iris suture eliminates the necessity of reaching in with forceps to grasp the iris unsupported by the lens. T h i s re-