Noticing the phenomenon that biological tissues will change its elasticity by orders of magnitude after it was frozen, we proposed in principle the strategy of using ultrasound elastography to monitor the formation and thawing of the iceball when performing a cryosurgery. Following our former theoretical evaluation, conceptual experiments were designed to apply ultrasound elastography to monitor three kinds of testing samples which includes: phantom embedded with glass block, phantom with tissues at normal temperature and phantom with frozen tissues inside. It was demonstrated for the first time that the ultrasound elastography could provide a high contrast picture on the ice ball during cryosurgery. The measurement errors involved in the application of the method was preliminarily analyzed and approaches to further improve the method were pointed out. With a much different value in elastography than that of water, monitoring the ice ball, the imaging target in clinics, is expected to be an important area for the application of ultrasound elastography.
Cryosurgery ; methods ; Elasticity Imaging Techniques ; methods ; Phantoms, Imaging ; Ultrasonics

No abstract available.
Bronchial Neoplasms/*surgery ; *Bronchoscopy ; Cryosurgery/*methods ; Humans ; Lung Neoplasms/*surgery

BACKGROUNDRenal sympathetic nerves are involved in the reflective activation of the sympathetic nervous system in circulatory control. Catheter-based renal denervation (RDN) ameliorated treatment-resistant hypertension safely, but 10%-20% of treated patients are nonresponders to radiofrequency denervation. The purpose of this study was to investigate the safety and efficiency of cryoablation for sympathetic denervation in a swine model and to explore a new way of RDN.

METHODSSeven swines randomly assigned to two groups: Renal cryoablation (CR) group and control group. The control group underwent renal angiogram only. The CR group underwent renal angiogram plus bilateral renal cryoablation. Renal angiograms via femoral were performed before denervation, after denervation and prior to the sacrifice to access the diameter of renal arterial and the pressure of aorta abdominalis. Euthanasia of the swine was performed on 28-day to access norepinephrine (NE) changes of the renal cortex and the changes of renal nerves.

RESULTSCryoablation did not induce severe complications at any time point. There was no significant change in diameter of renal artery. CR reduced systolic blood pressure (BP) from 145.50 ± 9.95 mmHg at baseline to 119.00 ± 14.09 mmHg. There was a slight but insignificant decrease in diastolic BP. The main nerve changes at 28-day consisted of necrosis with perineurial fibrosis at the site of CR exposure in conjunction with the nerve vacuolation. Compared with the control group, renal tissue NE of CR group decreased by 89.85%.

CONCLUSIONSPercutaneous catheter-based cryoablation of the renal artery is safe. CR could effectively reduce NE storing in the renal cortex, and the efficiency could be maintained 28-day at least.

Animals ; Cryosurgery ; methods ; Female ; Kidney ; innervation ; Male ; Swine ; Sympathectomy ; methods ; Treatment Outcome

The combination of the cryosurgery using LN2 and intelligent RF ablation therapeutic instrument based on the theory of local destruction is introduced in this paper, and this alternating therapy is believed to have a better controlling effect on tumor ablation. In heating period, a fuzzy algorithm is used to control the RF power to realize a more smoothly heating process to the target area.
Catheter Ablation ; instrumentation ; methods ; Cryosurgery ; instrumentation ; Equipment Design ; Humans ; Hyperthermia, Induced ; instrumentation ; methods ; Neoplasms ; surgery

Physical ablation is a new kind of tumor treatment which directly acts on local solid tumors to eradicate or destroy tumor tissues by use of various advanced physical techniques. Physical ablation can be classified by physical characteristics as thermal ablate therapy (TAT), cryoablation and electrical ablation. Recent studies and technical trend of these three physical ablation treatments are reviewed in this paper.
Animals ; Catheter Ablation ; methods ; Cryosurgery ; Humans ; Hyperthermia, Induced ; Neoplasms ; surgery ; therapy ; Salvage Therapy

The phase change process in cryosurgery is simulated here with finite element scheme. The calculated results are consistent with experimental results. The compared results confirm the feasibility of the enthalpy model and finite element simulation method. And the successive Freeze-thawing Circle and multi-probe cryosurgery process are further simulated and the characteristic of the thermal field and thermal gradient around cryoprobe are analyzed. The application of enthalpy mathematical model and finite element scheme provide useful simulating means for the cryosurgery and will be beneficial for the progressing and extending of the cryosurgery technology.
Computer Simulation ; Cryosurgery ; methods ; Finite Element Analysis ; Humans ; Models, Theoretical ; Phase Transition

Keloids are abnormally healed skin wounds that develop in the subpapillary layer of the dermis. They are a lesion with wide, raised and deep scars. They exceed the original dimensions of the wound and grow mounds upon mounds of collagen in a pseudotumor fashion. Their treatment may take several forms such as surgery, intralesional injection of steroid, compression, superficial irradiation, and combination therapy. However, absolute method is nothing until now. Recently, the cryosurgery shows relatively good effect in treatment, so we tried the clinical experience with cryosurgery in the treatment of keloids. Material and methods: During the past 2 years, we treated 20 individuals of the keloids with severe itching and pain. The age ranged from 5 to 45 years old. Only 6 cases were biopsied before and after cryotherapy. The cryosurgery set we used was Toitu model CR 201 N₂O gas (tip temperature in ­80℃) and was applied directly on the lesion about 4 to 5 minutes with slight compression. After cryosurgery in keloids, the following results were obtained: 1. It is both quick and easy method. 2. It is causes little or no pain and no loss of blood. 3. Integumentary normalization is rapid. The new scar tissue is smaller, and more elastic and soft. 4. The pain, itching and paresthesia commonly associated with keloid is usually disappeared. 5. Other treatment can be used after cryosurgery. 6. Histologic picture after cryosurgery is similar with the result of steroid injection. 7. The mechanism of the cryosurgery in keloids is the result of the direct tissue destroying action and cryoimmunologic reaction.
Cicatrix ; Collagen ; Cryosurgery* ; Cryotherapy ; Dermis ; Injections, Intralesional ; Keloid* ; Methods ; Paresthesia ; Pruritus ; Skin ; Wounds and Injuries

In recent years, the incidence of renal cancer has been increasing continuously. Surgical resection is the "gold standard" for the treatment of small renal cancer. However, local ablation therapy of renal cancer is undoubtedly the best choice for patients with short life expectancy, other complications, and impaired renal function who are not suitable for surgery. In recent years, with the development of ablation techniques and long-term follow-up, local ablation has shown good therapeutic effects. As many domestic hospitals are performing or planning to perform renal tumor cryoablation to improve the clinical cure rate and surgical safety of renal tumor cryoablation, it is necessary to standardize the surgical indications, contraindications, perioperative management, efficacy evaluation, and other common problems. Currently, there is no expert consensus regarding perioperative renal tumor cryoablation in China. To standardize the perioperative management of renal tumor cryoablation and related technical operations in clinical practice, and improve the effectiveness and safety of cryoablation, the expert committee of Tumor Interventional and Minimally Invasive Diagnosis and Treatment Continuing Education Base of the Chinese Anti-Cancer Association convened experts in related fields to discuss and formulate this consensus, which is hereby published, for clinical reference and application.
Humans ; Carcinoma, Renal Cell/surgery* ; Consensus ; Cryosurgery/methods* ; Kidney Neoplasms/pathology* ; Treatment Outcome ; China

OBJECTIVE: To compare low temperature coblation assisted tonsillectomy with conventional dissection tonsillectomy intra-operation and after-operation. METHOD: Ninety-two pedia-patients were randomly divided into coblation-assisted tonsillectomy group and the control group. Arthrocine EVac 70 T&A Wand was used for coblation-assisted tonsillectomy, and the energy set was 7. Conventional dissection tonsillectomy was operated in control group. The operating time,bleeding,tonsillar fossae healing and return to normal diet and activities, intraoperative complications were recorded separately. Postoperative pain of the pedia-patients was recorded daily using Wong Baker FACES pain scale for 10 days of after-operation. RESULT: Coblation assisted group had a shorter operative time than the control group (10.2 min vs. 36.5 min, P<0.001). The average amount of intraoperative bleeding of Coblation assisted group was (6.83+/-3.36) ml, while the control group was (30.07+/-7.04) ml. Pedia-patients of Coblation group had a better pain score on 1, 2, 3 days after operation than in control group, and there was no statistically significant difference on 4 to 10 days between the two groups. Coblation group ones returned to normal diet earlier than the control group, but both group required similar time returned to normal activities. There was one patient in control group,who required suturing to stop bleeding for active oropharyngeal bleeding on the 6th day after operation. CONCLUSION Comparing with traditional dissection, Coblation assisted tonsillectomy is easy to perform with less intraoperative bleeding, shorter operation time, earlier return to normal diet, less pain on 1st to 3rd day postoperatively.
Adolescent ; Child ; Child, Preschool ; Cold Temperature ; Cryosurgery ; methods ; Dissection ; methods ; Female ; Humans ; Male ; Tonsillectomy ; methods ; Tonsillitis ; surgery ; Treatment Outcome

Aged ; Atrial Flutter ; surgery ; Catheter Ablation ; adverse effects ; methods ; Cryosurgery ; adverse effects ; methods ; Female ; Humans ; Male ; Middle Aged