1. Tatsutani, K; Rubinsky, B; Onik, G; Dahiya, R.
Effect of thermal variables on frozen human primary prostatic
adenocarcinoma cells.
Urology, v.48, n.3, (1996): 441-447.
Abstract:
Objectives. Recent advances in imaging technology and cryotechnology have
rekindled interest in prostate cryosurgery. Cryosurgery, however, cannot
be applied precisely without knowing how the thermal variables used during
the procedure affect tissue destruction. The goal of this article is to
provide quantitative values for the relationship between thermal variables
during freezing and the destruction of human primary prostatic
adenocarcinoma cells. Methods. Human primary prostatic adenocarcinoma
cells were frozen with controlled thermal parameters, using a directional
solidification apparatus. Cell viability was determined after thawing,
using trypan blue and a two-dye fluorescent test and correlated to the
thermal variables used during freezing. Results. Human primary prostatic
adenocarcinoma cells are damaged by intracellular chemical damage when
frozen with cooling rates lower than 5 degree C/min and by intracellular
ice formation when frozen with cooling rates higher than 25 degree C/min.
A double freeze/thaw cycle is required to ensure complete cell destruction
at high subzero temperatures, which must be lower than -40 degree C for
the low cooling rates and lower than -19 degree C for the higher cooling
rate. Conclusions. Haphazard freezing does not necessarily destroy tissue
during cryosurgery; however, quantitative data on the relation between
thermal variables and frozen cell destruction can provide the means for
performing cryosurgery more precisely and with greater control over the
outcome of the procedure.
2. Simo, R; Sharma, V L.
Treatment of rhinophyma with carbon dioxide laser.
Journal of Laryngology and Otology, v.110, n.9, (1996): 841-846.
Abstract:
Rhinophyma is a slowly progressive, disfiguring disorder of the nose which
represents the end stage of acne rosacea. The cosmetic deformity is often
the reason for patients to seek medical attention. Over the years many
treatment modalities, including dermabrasion, electrocautery, excision and
grafting, decortication and cryosurgery amongst others, have been
described to treat this condition, but none of them are very satisfactory.
Special concern about the droplet dispersion of blood in dermabrasion have
made this method less acceptable as it poses a potential risk to health
workers. We describe a technique in which this proliferative disorder can
be treated, using carbon dioxide laser excision and vaporization. This
method provides a very dry surgical field which allows the sculpting of
the hypertrophic areas to be very effective, giving a very satisfactory
cosmetic result.
1. Rabin Y; Coleman R; Mordohovich D; Ber R; Shitzer A.
A new cryosurgical device for controlled freezing.
Cryobiology, 1996 Feb, 33(1):93-105.
(UI: 96410868)
Abstract: A new cryosurgical device was developed in this study to facilitate
examination of factors affecting the outcome of cryotreatment. Special
emphasis was placed on the control of the cooling rate at the freezing
front. In the new computer-controlled cryosurgical device, the controlling
variable is the cryoprobe temperature, which is calculated to ensure
prespecified cooling rates at the freezing front. Details of the new
cryodevice, results of a validation test, and the system characteristics
are presented in Part I of this study. In this part of the study initial
results of 13 in vivo experimental cryotreatments, including histological
observations, are presented. The in vivo pilot investigations include the
normal, healthy skin and the underlying skeletal muscle of the thighs in
rabbits. Using low cooling rate-controlled freezing, the new cryosurgical
device is demonstrated here as an effective surgical tool. An in vivo
temperature measurement technique is employed based on miniature
thermocouples and X-ray images. Thermal analysis of the heat transfer in
the cryotreated tissue is presented, based on the temperature measurements
and on numerical heat transfer simulations. Cryotreated tissue was
extracted either immediately or 4 or 7 days following the procedure. The
histological observations on the skeletal muscle of the 4- and 7-day
postcryoinjury were not substantially different. The effective penetration
depth of the cryolesion was in the range of 5-15 mm, possibly extending up
to 25 mm, depending on the specific area treated and operating parameters.
The cryotreatment resulted in complete destruction of cells in the skin
followed by rapid replacement by epithelial cells. Histological responses
to cryotreatment of skeletal muscle were similar to those resulting from a
range of traumatic episodes, e.g., crush damage. It was also found that
most of the blood vessels in the cryotreated region remained intact without
histological evidence of extravasation of erythrocytes.
2. Rabin Y; Shitzer A.
A new cryosurgical device for controlled freezing.
Cryobiology, 1996 Feb, 33(1):82-92.
(UI: 96410867)
Abstract: A new cryosurgical device utilizing liquid nitrogen, which is a
modification of an existing commercial system, was developed. In the new
computer-controlled cryodevice the temperature of the cryoprobe is
controlled by means of an electrical heating element. The desired
temperature-forcing function is calculated to ensure a specified constant
cooling rate at the freezing front. The new device facilitates real-time
data processing, and, in particular, simulation of the heat transfer
processes. A series of tests was performed to study the characteristics of
the cryodevice and to validate the underlying assumptions. These tests were
performed using organic tissue, i.e., potatoes, as an in vivo simulating
medium of biological tissue. The differences between experimental data and
computed results were found to be within +/-0.5 degrees C, which falls
within the uncertainty range of the experimental temperature measurements.
A typical control error of the new device is within +/-0.3 degrees C, prior
to the formation of the freezing front, and +/-0.6 degrees C thereafter,
which is of the same order of magnitude as the uncertainty range of the
temperature measurements. The new device is capable of producing maximal
cooling rates of 50 degrees C/min down to temperatures of -165 degrees C
and a maximal heating rate of 300 degrees C/min. The maximal cooling power
of the cryoprobe, due to LN2 boiling, is 80 W; the maximal electrical
heating power of the cryoprobe is 160 W. Precooling of the device requires
about 30 min, and it can be operated continuously for about 3 h. Initial
results of experimental in vivo cryosurgery performed on rabbit hindlimbs,
including histological observations and thermal analysis, are presented in
the second part of this study.
3. Otani Y; Morishita Y; Ishikawa S; Hamada Y; Otaki A; Yoshida I; Misaki T.
Successful treatment of Wolff-Parkinson-White syndrome with concomitant
mitral stenosis by simultaneous surgery.
Surgery Today, 1996, 26(3):196-8.
(UI: 96244247)
Abstract: We report the case of a 61-year-old man with type B
Wolff-Parkinson-White (WPW) syndrome associated with a right
atrioventricular (AV) accessory pathway and concomitant mitral stenosis,
who underwent successful operative treatment by simultaneous surgery. His
preoperative course had been characterized by cardiac failure and repeated
episodes of atrial tachyarrhythmia, in the form of fibrillation and
flutter, which were difficult to control by conventional medication.
Preoperative electrocardiograms (ECGs) had suggested that the accessory
pathway was located in the right posterior to posteroseptal wall; however,
at the time of surgery, epicardial electrophysiological mapping with sock
electrodes revealed a preexcitation area in the AV groove at the lateral
right margin of the heart. This discrepancy was thought to have been due to
the presence of mitral stenosis or multiple accessory pathways. Thus,
division and cryoablation of the accessory pathway by an endocardial
approach, in addition to mitral valve replacement, were performed under
cardiopulmonary bypass. His postoperative course was uneventful, and
subsequent ECGs revealed that the delta waves had disappeared. The
successful outcome of this patient demonstrates the effectiveness of
simultaneous surgery for WPW syndrome associated with valvular disease.
4. Khwarg SI; Yu HG; Yu YS.
Change of refraction in premature infants after cryotherapy for
retinopathy of prematurity between the age of six months and three years.
Korean Journal of Ophthalmology, 1995 Dec, 9(2):111-6.
(UI: 96415402)
Abstract: To investigate the chronological change of refraction in premature
infants after cryotherapy for retinopathy of prematurity (ROP), cycloplegic
refractions had been performed at 6 months and 3 years after term in
premature infants who underwent cryotherapy for ROP. The changes of
refractions between the two study ages were evaluated not only in the total
cryo-treated eyes, but also in the subdivided groups according to the
posterior pole appearances. In the total 61 eyes of 32 premature infants,
mean spherical equivalents were -4.05D vs. -5.94D (6 months vs. 3 years) (p
= 0.0001). In the normal posterior pole group (48 eyes), mean spherical
equivalents were -3.45D vs. -5.68D (6 months vs. 3 years) (p = 0.0000), and
in the abnormal posterior pole group (13 eyes), -6.28D vs. -6.86D (6 months
vs. 3 years) (p = 0.6496). These results mean that there is a myopic
progressive change between 6 months and 3 years after term in the
cryo-treated eyes for acute ROP and it is more evident in the eyes with
normal posterior pole.
5. Sklar GN; Koschorke GM; Filderman PS; Naslund MJ; Jacobs SC.
Laparoscopic monitoring of cryosurgical ablation of the prostate.
Surgical Laparoscopy and Endoscopy, 1995 Oct, 5(5):376-81.
(UI: 96108338)
Abstract: Cryosurgical ablation of the prostate has resurfaced as a potential
treatment option for organ-confined adenocarcinoma of the prostate. This
study examines the temperatures achieved at the anterior prostatic capsule
during the freeze-thaw cycle of transperineal cryosurgical ablation of the
prostate. Additionally, as there was direct laparoscopic visualization of
the prostate, frost forming outside the prostate would have been detected.
Two patients underwent endoscopic extraperitoneal pelvic lymphadenectomy
followed, with patients under the same anesthetic, by transperineal
cryosurgical ablation of the prostate. Nadir prostatic capsular
temperatures reached - 28 and - 36 degrees C, respectively, occurring
approximately 13 min into the freezing phase. At these temperatures, no
frost was observed endoscopically at the ventral surface of the prostate.
Ice was palpated with endoscopic probes several millimeters below the
ventral capsular surface. These nadir temperatures are lower than those of
previous studies on cryosurgical ablation of the human prostate. Further
studies need to examine the temperatures required to produce cell death and
to determine whether periprostatic tissues can be treated safely and
effectively for locally advanced disease.
6. Sullivan TJ; Clarke MP; Tuli R; Devenyi R; Harvey P.
General anesthesia with endotracheal intubation for cryotherapy for
retinopathy of prematurity.
European Journal of Ophthalmology, 1995 Jul-Sep, 5(3):187-91.
(UI: 96115433)
Abstract: We present a technique for treating retinopathy of prematurity (ROP)
with cryotherapy under general anesthesia, administered and monitored by a
neonatologist, with endotracheal intubation in the neonatal intensive care
unit that avoids the serious systemic complications associated with the
administration of local anesthetics. Although no significant complications
arose in this series, having the intubated infant monitored by trained
neonatology staff allows appropriate management should complications arise.
We have used this technique to treat 20 eyes with threshold ROP. The mean
time to extubation was 40.2 hours. The systemic status and discharge from
the neonatal intensive care unit were not influenced by the general
anesthesia. This technique allows quick and accurate application of the
cryotherapy in a stable and controlled setting. We recommend that
physicians consider cryotherapy under general anesthesia with endotracheal
intubation for infants with ROP. This technique allows ROP to be treated
adequately with minimal risk to the infant.
7. Gopal L; Sharma T; Ramachandran S; Shanmugasundaram R; Asha V.
Retinopathy of prematurity: a study.
Indian Journal of Ophthalmology, 1995 Jun, 43(2):59-61.
(UI: 96415386)
Abstract: A total of 50 infants of less than 2000 gm birth weight were screened
for retinopathy of prematurity (ROP) by binocular indirect ophthalmoscopy.
The incidence of ROP was found in 19 patients (38%). Of these, 8 patients
(16 eyes) had threshold disease. Significantly, occurrence of threshold ROP
was seen in both 1600 gm birth weight in one infant and in the absence of
oxygen administration in 2 infants. Ten of the 16 eyes underwent
therapeutic intervention while 6 eyes did not receive treatment for lack of
consent from the parents. The treatment consisted of indirect laser
photocoagulation (8 eyes) and transconjunctival cryopexy (2 eyes). Good
regression of the disease (favourable outcome) was noted in all the treated
eyes.
8. Benson WE.
Familial exudative vitreoretinopathy.
Transactions of the American Ophthalmological Society, 1995, 93:473-521.
(UI: 96358722)
Abstract: PURPOSE: To evaluate the natural history of Familial Exudative
Vitreoretinopathy (FEVR) with emphasis on the effect of the age of onset on
its severity and on the development of late complications such as cataract
and retinal detachment. Also, to evaluate affected patients for DNA
abnormalities. METHODS: The records of thirty-nine patients with FEVR were
studied. All were asked to come in for a final follow-up examination. The
referring physician was asked to provide the latest findings for those who
could not. On 10 patients, karyotypes were prepared. RESULTS: Only 2 of 28
patients whose onset of symptoms was prior to their third birthday had a
final visual acuity of 20/200 or better. Older patients had a better
prognosis, because they were more likely to have asymmetrical retinal
deterioration with only one eye deteriorating. Preservation of good visual
acuity into the teens and later was no guarantee that deterioration would
not occur. In 3 eyes of 4 patients who were asymptomatic until 15 years of
age, the final visual acuity was counting fingers or worse. In 5 patients,
retinal detachment developed 6 to 17 years after apparent stabilization.
The karyotype of 10 patients showed no evidence for rearrangement, altered
size, translocations or deletions of chromosome 11 or any other chromosome.
Of the 31 eyes in patients older than 15 years, 10 (32%) had a significant
cataract. Three eyes underwent cataract surgery. CONCLUSIONS: The prognosis
for infants with FEVR is extremely poor and the long-term prognosis for
patients with a later onset of the condition is guarded. Retinal
detachment, macular dragging, and cataract are common late complications
which can develop even in patients whose eye findings appear to be stable.
Karyotype studies ruled out involvement of chromosome 11 or others at a
gross level, but did not exclude them at the location for some genetic
defect related to FEVR because single base changes and small deletions or
insertions may be undetectable by the methods utilized.
1. Cozzi, P J; Lynch, W J; Robson, N; Vonthethoff, L; Lumley, T; Morris, D L.
In vitro and in vivo assessment of urethral warming catheters for the
transperineal cryoablation of prostatic carcinoma.
British Journal of Urology, v.78, n.4, (1996): 589-595.
Abstract:
Objective: To evaluate the two most common urethral warming catheters
currently available for their effectiveness in preventing urethral injury
in an animal model and thus during transperineal cryosurgery for the
treatment of prostate cancer. Patients, materials and methods: The warming
efficiency of the variable-diameter thin latex-balloon catheter (Cook,
Australia) and the fixed-diameter PVC catheter (Candela, USA) were
evaluated in a water-bath. A sheep model was then used for subsequent
experiments to further evaluate the better catheter. The technique used
for the insertion of the Cook catheter in a series of 33 patients treated
with prostate cryosurgery is also described. Results: In vitro, the Cook
catheter was more effective (P lt 0.01) than the Candela catheter in
preventing localized cooling. In vivo, results in five animals showed that
the urethral epithelium was viable in all sections that had been protected
by the catheter and focally denuded or necrotic in those sections not
protected, with each animal used as its own control (P lt 0.01 Fisher's
exact test). The 33 patients treated while using the Cook catheter had no
subsequent complications. Conclusion: The urethral warming catheter
currently in use for prostatic cryosurgery in Australia is more effective
in vitro than its competitor and is effective in preventing urethral
injury in vivo.
2. Rivoire, M L; Kaemmerlen, P; Molina, G.
Safe placement of large cryoprobes during cryosurgery of deep liver
metastases.
Journal of Surgical Oncology, v.63, n.1, (1996): 61-62.
3. Berger, W K; Uhrik, B.
Freeze-induced shrinkage of individual cells and cell-to-cell propagation
of intracellular ice in cell chains from salivary glands.
Experientia (Basel), v.52, n.9, (1996): 843-850.
Abstract:
The formation of intracellular ice (IIF), usually a lethal event to be
avoided when cryopreserving cells, should, however, be enforced during the
cryosurgical destruction of tumour cells. IIF has been investigated so far
only in single cells in suspension. Because cells in tissues cannot be
successfully cryopreserved, in contrast to single cells in suspension, the
mechanism of IIF in tissues may depend on factors that facilitate IIF. We
studied IIF in cell strands from salivary glands, which represent a simple
form of a tissue. Their cells are connected by channels responsible for
intercellular communication. A substantial fraction of cell dehydration
during freezing occurs before cells are encapsulated by ice, and the
degree of this pre-ice-front shrinkage appears to influence IIF. In
strands with coupled cells IIF spread from one cell to adjacent cells in a
sequential manner with short delays (200-300 ms), suggesting cell-to-cell
propagation via intercellular channels. In strands pretreated with
decoupling agents (dinitrophenol, heptanol), sequential IIF was absent.
Instead, formation of ice was random, with longer and variable delays
between consecutive darkenings indicating IIF. Results suggest that the
mechanism of IIF spread, and consequently the degree of cryodamage in
tissue, can be influenced by the presence of intercellular channels (gap
junctions).
1. Tatsutani K; Rubinsky B; Onik G; Dahiya R.
Effect of thermal variables on frozen human primary prostatic
adenocarcinoma cells.
Urology, 1996 Sep, 48(3):441-7.
(UI: 96397605)
Abstract: OBJECTIVES: Recent advances in imaging technology and cryotechnology
have rekindled interest in prostate cryosurgery. Cryosurgery, however,
cannot be applied precisely without knowing how the thermal variables used
during the procedure affect tissue destruction. The goal of this article is
to provide quantitative values for the relationship between thermal
variables during freezing and the destruction of human primary prostatic
adenocarcinoma cells. METHODS: Human primary prostatic adenocarcinoma cells
were frozen with controlled thermal parameters, using a directional
solidification apparatus. Cell viability was determined after thawing,
using trypan blue and a two-dye fluorescent test and correlated to the
thermal variables used during freezing. RESULTS: Human primary prostatic
adenocarcinoma cells are damaged by intracellular chemical damage when
frozen with cooling rates lower than 5 degrees C/min and by intracellular
ice formation when frozen with cooling rates higher than 25 degrees C/min.
A double freeze/thaw cycle is required to ensure complete cell destruction
at high subzero temperatures, which must be lower than -40 degrees C for
the low cooling rates and lower than -19 degrees C for the higher cooling
rate. CONCLUSIONS: Haphazard freezing does not necessarily destroy tissue
during cryosurgery; however, quantitative data on the relation between
thermal variables and frozen cell destruction can provide the means for
performing cryosurgery more precisely and with greater control over the
outcome of the procedure.
2. Rosenberg LF; Karalekas DP; Krupin T; Hyderi A.
Cyclocryotherpay and noncontact Nd:YAG laser cyclophotocoagulation in
cats.
Investigative Ophthalmology and Visual Science, 1996 Sep, 37(10):2029-36.
(UI: 96409160)
Abstract: PURPOSE: To investigate physiological and histologic alterations of
the cat eye in response to cyclocryotherapy (CCT) and noncontact
transscleral Nd:YAG laser cyclophotocoagulation (TSNYC). METHODS: One eye
of 29 cats was treated with 12 applications (1 minute, -80 degrees C) of
CCT or 80 applications of noncontact TSNYC (7 to 9 J, retrofocus 3.6 mm).
Blood-aqueous barrier function was studied measuring aqueous protein and
fluorescein concentration after intravenous dye injection. Ocular blood
flow was determined using 85Sr microspheres. RESULTS: Intraocular pressure
after CCT was 29% lower in the treated than in the control eye after 3 and
12 weeks. After TSNYC, pressure was reduced by 34% at 3 weeks and by 27%
after 12 weeks. Aqueous protein concentration was elevated in all treated
eyes. Neither technique altered tonographic outflow facility or episcleral
venous pressure. Calculated aqueous flow was lower in the treated eye than
in the control eye 3 and 12 weeks after each cyclodestructive procedure.
After CCT, anterior chamber fluorescein concentration was 2.5 times greater
in 3-week and 3 times greater in 12-week eyes. After TSNYC, fluorescein
concentration was 3 and 3.5 times greater at 3 and 12 weeks, respectively.
Ciliary body blood flow in control eyes was similar to CCT and TSNYC eyes.
Histopathology 12 weeks after CCT and TSNYC showed pigment dispersion,
disorganized architecture, and cystic elevation of the nonpigmented ciliary
epithelium. Areas of absent pigmented and nonpigmented epithelium at the
ciliary process base were more discrete in TSNYC eyes. Electron microscopy
demonstrated normal junctional complexes. CONCLUSIONS: CCT and TSNYC lower
pressure by reducing aqueous formation. Ciliary body blood flow is not
altered after either technique. Both techniques result in similar
histologic disruption of the ciliary epithelium, resulting in breakdown of
the blood-aqueous barrier.
3. Rabin Y; Steif PS; Taylor MJ; Julian TB; Wolmark N.
An experimental study of the mechanical response of frozen biological
tissues at cryogenic temperatures.
Cryobiology, 1996 Aug, 33(4):472-82.
(UI: 96358208)
Abstract: An experimental study of the mechanical response of frozen soft
biological tissues to applied compressive stresses is presented. This study
is related to the mechanical stresses that develop due to the contraction
of frozen tissues in cryopreservation as well as in cryosurgical
procedures. The main concept in this study is that the stresses associated
with the constrained contraction of the frozen tissue, i.e., due to
temperature variations within the frozen tissue, can be simulated by an
external mechanical load which is applied to the frozen tissue while the
tissue is maintained at a uniform temperature. A new apparatus for
measuring compressive stresses and strains of frozen biological tissues in
cryogenic temperature range is presented. A new technique for processing
the fresh biological tissue into a cylindrical frozen sample for mechanical
testing is introduced. Results of compression tests on rabbit liver,
kidney, and brain are presented and are compared with available data from
the literature on sea ice and single ice crystals. An unusual response of
frozen biological tissues to compressive stress was observed: after the
initial, roughly linear elastic portion there was a series of sudden stress
drops at constant strain, each followed by a linear increase of stress with
strain to the next drop. This phenomenon, which is attributed to the
accumulation of microcracks, broadly resembles plastic deformation, and
thus provides some support for simple mechanical models invoked in
theoretical studies.