Evaluation of cryoablation using a prototype cryoablation needle in swine liver.

BACKGROUND/AIMS: Pancreatic cancer poses significant challenges due to its tendency for late-stage diagnosis and high mortality rates. Cryoablation, a technique used to treat various types of cancer, has shown potential in enhancing the prognosis of pancreatic cancer when combined with other therapies. However, its implementation is often limited by the need for lengthy procedures and specialized equipment. This study aims to develop a cryoablation needle optimized for endoscopic ultrasonography to simplify its application in treating pancreatic cancer. METHODS: The study involved conducting cryoablation experiments on swine liver tissue. It utilized cryo-needles to evaluate the extent of cell death across various temperatures and durations of cryoablation. RESULTS: The cryoablation system, which employed liquid carbon dioxide, achieved rapid cooling, reaching temperatures below -60 °C within 30 seconds and maintained the cryoablation process for 200 seconds. These conditions resulted in necrosis of the liver tissue. Notable cellular changes were observed up to 15 mm away from the cryoablation needle. CONCLUSIONS: This experimental study successfully demonstrated the efficacy of using a cryo-needle for cryoablation in swine liver tissue. Further trials involving pancreatic tissue are expected to verify its effectiveness, underscoring the importance of continued research to establish its role as a complementary therapy in pancreatic cancer treatment.

Cryoprobe-Assisted Excision of Cavernous Hemangioma of the Orbit: A Clinical Case Report.

This case report details the management of orbital cavernous hemangioma in a middle-aged female. The treatment involved a medial orbitotomy combined with an innovative application of a cryoprobe. This approach underscores the benefits of open orbitotomy, particularly when combined with cryoextraction. This combination provides improved control over bleeding and results in a substantial reduction in surgical time, offering valuable insights in the context of the contemporary trend towards endoscopic surgeries.

Cryosurgery of eyelid actinic keratosis and the effect of adrenaline in local anesthetics - temperature mapping using IR thermography.

PURPOSE: The efficacy of cryosurgery is believed to depend on the thaw time. The presence of adrenaline in local anesthetics affects blood perfusion, and may thus also affect the thaw time. The aim of the present study was to use IR thermography to monitor the tissue temperature during cryosurgery of actinic keratosis, and to assess the effect of adrenaline in local anesthetics. METHODS: Twelve patients with actinic keratosis in the periorbital region underwent cryosurgery. The temperature was continuously mapped using a high-precision IR camera and was also visually assessed by the surgeon. The results obtained when employing local anesthetics with and without adrenaline were compared. RESULTS: The temperature change during thawing showed a triphasic pattern. The thaw time was significantly longer when using an anesthetic with adrenaline. This was observed with both IR thermography and by visual observation. CONCLUSIONS: The findings indicate that a longer freezing time may be needed when using a local anesthetic without adrenaline to achieve the same cryo-effect as when using a local anesthetic with adrenaline. A larger clinical trial is needed on the effects of using local anesthetics with and without adrenaline to treat actinic keratosis, for example, the clearance rate, before recommendations can be made concerning their use.

Ultrasound-guided cryoablation of early breast cancer: safety, technical efficacy, patients' satisfaction, and outcome prediction with MRI/CEM: a pilot case-control study.

BACKGROUND: This pilot prospective study aimed to evaluate ultrasound-guided cryoablation of breast cancer (BC) by assessing: (i) technical efficacy as the presence of necrosis in surgical specimens and rate of complete tumor ablation; (ii) safety as incidence and severity of complications; and (iii) patients' satisfaction using a dedicated questionnaire. In addition, (iv) we tested the capability of magnetic resonance imaging (MRI) or contrast-enhanced mammography (CEM) to predict cryoablation efficacy. METHODS: From 07/2022 to 01/2023, we enrolled 20 patients with early-stage BC scheduled for breast surgery. Ten of them, with a cryo-feasible cancer location, were sent to cryoablation (cryo-group) and ten to routine surgical practice (control group). Both groups underwent surgery and were asked to answer a satisfaction questionnaire. RESULTS: Of eleven patients screened for cryoablation, only one refused to be treated at another hospital (acceptance rate 10/11, 91%). Surgery was quadrantectomy in 19 cases and mastectomy in 1. In the cryo-group, the procedure was completed and steatonecrosis was observed in 10/10 cases, with complete tumor ablation in nine of them. The post-procedural status was evaluated with MRI in five patients, with CEM in four patients, and with ultrasound in one patient who refused MRI and CEM. MRI or CEM correctly predicted complete cryoablation in eight patients and incomplete cryoablation in one patient. Patients in both groups did not have serious complications and responded positively to satisfaction questionnaires. CONCLUSION: Ultrasound-guided cryoablation of early-stage BC is well accepted by patients, effective, and safe. MRI and CEM were able to predict the procedure's technical efficacy. TRIAL REGISTRATION: https://clinicaltrials.gov/study/NCT05727813 updated February 14, 2023. RELEVANCE STATEMENT: Our pilot study showed that ultrasound-guided cryoablation is a promising nonsurgical alternative for treating early-stage BC. KEY POINTS: Ultrasound-guided cryoablation was effective and safe in early BC patients. The procedure was well-tolerated, with low morbidity and high patient satisfaction. MRI and CEM predicted cryoablation efficacy, in accordance with histopathologic findings. Cryoablation can be considered a potential alternative to surgery in selected patients.

Propensity score-matched analysis comparing robot-assisted partial nephrectomy and image-guided percutaneous cryoablation for cT1 renal cell carcinoma.

OBJECTIVES: This study aimed to compare the clinical outcomes of robot-assisted partial nephrectomy (RAPN) and image-guided percutaneous cryoablation (IG-PCA) for clinical T1 renal cell carcinoma. MATERIALS AND METHODS: We conducted a retrospective analysis of 679 patients with clinical T1 renal cell carcinoma treated with RAPN or IG-PCA between 2012 and 2021. Propensity scores were calculated via logistic analysis to adjust for imbalances in baseline characteristics. We compared oncological and functional outcomes between the 2 treatment groups. RESULTS: Following the matching process, 108 patients were included in each group. No patient in the RAPN group developed local recurrence. In the IG-PCA group, three patients experienced local tumor progression. The patients underwent salvage thermal ablations by the secondary technique; 2 underwent IG-PCA and 1 underwent microwave ablation, resulting in a local control rate of 100%. The Kaplan-Meier analysis showed no statistically significant differences between the groups in terms of 5-year recurrence-free survival, metastasis-free survival, and overall survival (log-rank test; P = 0.11, P = 0.64, and P = 0.17, respectively). No significant differences were observed in the 2 treatments in major and overall complication rates (P = 0.75 and P = 0.82, respectively). Both groups showed similar rates of less than 10% estimated glomerular filtration rate decline at 12 months post-treatment and 5-year renal function preservation rates (P = 0.88 and P = 0.38, respectively). CONCLUSIONS: IG-PCA demonstrated oncological outcomes comparable to those of RAPN. RAPN addressed the disadvantages of conventional procedures and allowed for safety outcomes comparable to IG-PCA.

Successful Treatment of Angiolymphoid Hyperplasia with Eosinophilia Associated with Scalp Demodicosis Using Cryotherapy and Topical Metronidazole.

Angiolymphoid hyperplasia with eosinophilia (ALHE) is a rare, benign, vasoproliferative tumour. We report a 25-year-old female patient who reported in 2021 to a dermatology clinic in Rustaq, Oman, with multiple, grouped, erythematous dome-shaped papules and nodules of 6 months duration on the left temporo-occipital region. Biopsy findings were consistent with a diagnosis of ALHE with evidence of Demodex mite infestation in the sebaceous ducts. The patient demonstrated significant improvement following 7 weeks of treatment with multiple cryotherapy sessions and topical application of metronidazole gel. This case suggests that scalp demodicosis may represent a novel trigger for the development of ALHE.

Targeted precision cryotherapy for acne vulgaris.

BACKGROUND: Acne vulgaris poses a significant dermatological challenge, necessitating alternative treatments due to limitations and side effects associated with current therapies. This pilot clinical trial investigated the feasibility and efficacy of precision cryotherapy for acne vulgaris. METHODS: A total of 20 volunteers underwent targeted precision cryotherapy using a carbon dioxide-based device. Treatment outcomes were assessed using various parameters, including Investigator Global Assessment (IGA) score, acne lesion count, erythema index (EI), global evaluation score, and participant satisfaction. Safety monitoring included adverse event reporting and physical examination. RESULTS: Precision cryotherapy demonstrated a significant reduction (90.25%) in the acne lesion count by week 4, with clinical improvement indicated by IGA score reduction (p < 0.001). The EI showed notable improvements at weeks 1, 2, and 4. The global evaluation score demonstrated a 75%-100% clinical improvement at Visit 4. Participants reported high satisfaction (6.75 ± 0.79) with the procedure. No adverse event or discomfort was reported. CONCLUSION: Precision cryotherapy effectively improved acne lesions, which was safe and satisfactory for participants. These findings suggest its potential as an alternative therapeutic modality, especially for populations with limited treatment options. Further research is needed to validate the results and explore underlying mechanisms.

Invasive strategies for rhythm control of atrial fibrillation: a narrative review.

Atrial fibrillation (AF) is the most common sustained tachyarrhythmia and its increasing prevalence has resulted in a growing healthcare burden. A recent landmark randomized trial, the EAST-AFNET 4 (Early Treatment of Atrial Fibrillation for Stroke Prevention Trial), highlighted the importance of early rhythm control in AF, which was previously underemphasized. Rhythm control therapy includes antiarrhythmic drugs, direct-current cardioversion, and catheter ablation. Currently, catheter ablation is indicated for patients with AF who are either refractory or intolerant to antiarrhythmic drugs or who exhibit decreased left ventricular systolic function. Catheter ablation can be categorized according to the energy source used, including radiofrequency ablation (RFA), cryoablation, laser ablation, and the recently emerging pulsed field ablation (PFA). Catheter ablation techniques can also be divided into the point-by-point ablation method, which ablates the pulmonary vein (PV) antrum one point at a time, and the single-shot technique, which uses a spherical catheter to ablate the PV antrum in a single application. PFA is known to be applicable to both point-by-point and single-shot techniques and is expected to be promising owing to its tissue specificity, resulting in less collateral damage than catheter ablation involving thermal energy, such as RFA and cryoablation. In this review, we aimed to outline catheter ablation for rhythm control in AF by reviewing previous studies.

Guideline No. 453: Endometrial Ablation in the Management of Abnormal Uterine Bleeding.

OBJECTIVE: To provide an update of the current evidence-based guideline on the techniques and technologies used in endometrial ablation, a minimally invasive technique for the management of abnormal uterine bleeding of benign origin. TARGET POPULATION: Women of reproductive age with abnormal uterine bleeding and benign pathology with or without structural abnormalities. BENEFITS, HARMS, AND COSTS: Implementation of the guideline recommendations will improve the provision of endometrial ablation as an effective treatment for abnormal uterine bleeding. Following these recommendations would allow the surgical procedure to be performed safely and maximize success for patients. EVIDENCE: The guideline was updated with published literature retrieved through searches of Medline and the Cochrane Library from January 2014 to April 2023, using appropriate controlled vocabulary and keywords (endometrial ablation, hysteroscopy, menorrhagia, heavy menstrual bleeding, abnormal uterine bleeding, hysterectomy). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies written in English. Grey (unpublished) literature was retrieved from the Association of Obstetricians and Gynecologists of Quebec (AOGQ) in 2023. VALIDATION METHODS: The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See Appendix A (Tables A1 for definitions and A2 for interpretations of strong and conditional [weak] recommendations). INTENDED AUDIENCE: Obstetricians, gynaecologists, and primary care providers. SOCIAL MEDIA ABSTRACT: This is an updated version of the 2015 SOGC Endometrial Ablation guideline. The authors discuss special considerations, update evidence, and make new fluid deficit recommendations. SUMMARY STATEMENTS: RECOMMENDATIONS.

A practical device to produce consistent, controlled cryoinjury on the skin.

It has long been known that sensitivity to cold-induced damage can vary greatly between different cell types, with lethal temperatures reportedly ranging from -2 °C for canine osteocytes, to -70 °C for mammary adenocarcinomas. This suggests that, for certain applications, "therapeutic windows" may exist wherein the cryosurgery temperature could be controlled to specifically target more cold-sensitive cell types, while sparing less sensitive cells. However, this potential selectivity has not been developed into practical clinical treatments, in part because of a lack of available investigative tools that can provide consistent, reproducible cooling within the desired temperature range. Here we describe an experimental cryosurgery tool that allows user control over the three key cryosurgery parameters - temperature, pressure, and duration. The tool is composed of inexpensive components that are generally accessible in most laboratory settings, and could be a practical investigative tool for developing and optimizing novel topical cryosurgery approaches.

Acceptance and results of cryoablation for the treatment of early breast cancer in non-surgical patients.

OBJECTIVES: Evaluate acceptance of percutaneous cryoablation (PCA) treatment by patients with early breast cancer (BC) who choose not to have surgery and present our experience in the use of PCA for the local control of BC in this group of patients. METHODS: All biopsy-proven early BC diagnosed in our institution as non-surgical patients between January 2020 and December 2023 were retrospectively reviewed. We recorded if PCA was offered and if it was accepted by the patient. PCA was performed under ultrasound (US) guidance, using a liquid nitrogen-based system. Mammography and US or contrast-enhanced mammography follow-up was scheduled every 6 months for 5 years. Patient's tolerance to the procedure, adverse effects, and results regarding local control of the disease were assessed. RESULTS: A total of 66 early BC were diagnosed in 63 patients who decided not to have surgery. Median age was 88 years (range 60-99 years). Forty-three (95.6%) of the 45 patients offered PCA accepted. Thirty-nine malignant tumours (median size 24 mm) underwent PCA. All cases were previously reviewed in a multidisciplinary tumour board. Complete tumour necrosis was achieved in 81.3% of the cases followed for ≥ 6 months. After a median follow-up of 16 months, the complete ablation rate in Luminal BC ≤ 25 mm was 100%. No major complications were seen. CONCLUSIONS: Non-surgical patients with early BC accepted PCA when the treatment was offered. PCA is safe, effective, and well-tolerated outpatient procedure. The study outcomes suggest that PCA could be an alternative to surgery for the management of BC in this group of patients. ADVANCES IN KNOWLEDGE: Patients with early BC who choose not to have surgery accept PCA. This percutaneous approach probably allows local control of early BC, mainly in ≤25 mm Luminal tumours.

Optical Sensing of Tissue Freezing Depth by Sapphire Cryo-Applicator and Steady-State Diffuse Reflectance Analysis.

This work describes a sapphire cryo-applicator with the ability to sense tissue freezing depth during cryosurgery by illumination of tissue and analyzing diffuse optical signals in a steady-state regime. The applicator was manufactured by the crystal growth technique and has several spatially resolved internal channels for accommodating optical fibers. The method of reconstructing freezing depth proposed in this work requires one illumination and two detection channels. The analysis of the detected intensities yields the estimation of the time evolution of the effective attenuation coefficient, which is compared with the theoretically calculated values obtained for a number of combinations of tissue parameters. The experimental test of the proposed applicator and approach for freezing depth reconstruction was performed using gelatin-based tissue phantom and rat liver tissue in vivo. It revealed the ability to estimate depth up to 8 mm. The in vivo study confirmed the feasibility of the applicator to sense the freezing depth of living tissues despite the possible diversity of their optical parameters. The results justify the potential of the described design of a sapphire instrument for cryosurgery.

Feasibility and safety of percutaneous intramyocardial septal cryoablation: A canine model with 6-month follow-up.

Echocardiography-guided percutaneous intramyocardial septal radiofrequency ablation (PIMSRA, Liwen procedure) is a novel treatment option for hypertrophic obstructive cardiomyopathy (HOCM). The safety and feasibility of using this procedure for cryoablation are unknown. We aimed to investigate the feasibility and safety of echocardiography-guided percutaneous intramyocardial septal cryoablation (PIMSCA) for septal thickness reduction in a canine model. Eight canines underwent PIMSCA, and had electrocardiography, echocardiography(ECG), myocardial contrast echocardiography (MCE), serological and pathological examinations during the preoperative, immediate postoperative, and 6-month follow-up. All eight canines underwent successful cryoablation and continued to be in sinus rhythm during ablation and without malignant arrhythmias. MCE showed that the ablation area had decreased myocardial perfusion after the procedure. Troponin I levels were significantly elevated [0.010 (0.005, 0.297) ng/mL vs. 3.122 (1.152, 7.990) ng/mL, p < 0.05)]. At 6-month follow-up after the procedure, all animals were alive, with thinning of the interventricular septum (7.26 ± 0.52 mm vs. 3.86 ± 0.29 mm, p < 0.05). Echocardiography showed no significant decrease in the left ventricular ejection fractions (LVEF) (54.32 ± 2.93 % vs. 54.70 ± 2.47 %, p > 0.05) or changes by pulse-wave Doppler E/A (1.17 ± 0.43 vs. 1.07 ± 0.43, p > 0.05), E/e' (8.09 ± 1.49 vs. 10.05 ± 2.68, p > 0.05). Pathological findings proved the effectiveness of cryoablation in myocardial tissues. We observed pericardial effusions and premature ventricular complexes (PVCs) associated with the procedure. Our findings provided preliminary evidence of the safety and feasibility of PIMSCA in reducing interventricular septum, which provides a potentially new treatment option for HOCM.

AGA Clinical Practice Guideline on Endoscopic Eradication Therapy of Barrett's Esophagus and Related Neoplasia.

BACKGROUND & AIMS: Barrett's esophagus (BE) is the precursor to esophageal adenocarcinoma (EAC). Endoscopic eradication therapy (EET) can be effective in eradicating BE and related neoplasia and has greater risk of harms and resource use than surveillance endoscopy. This clinical practice guideline aims to inform clinicians and patients by providing evidence-based practice recommendations for the use of EET in BE and related neoplasia. METHODS: The Grading of Recommendations Assessment, Development and Evaluation framework was used to assess evidence and make recommendations. The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients, conducted an evidence review, and used the Evidence-to-Decision Framework to develop recommendations regarding the use of EET in patients with BE under the following scenarios: presence of (1) high-grade dysplasia, (2) low-grade dysplasia, (3) no dysplasia, and (4) choice of stepwise endoscopic mucosal resection (EMR) or focal EMR plus ablation, and (5) endoscopic submucosal dissection vs EMR. Clinical recommendations were based on the balance between desirable and undesirable effects, patient values, costs, and health equity considerations. RESULTS: The panel agreed on 5 recommendations for the use of EET in BE and related neoplasia. Based on the available evidence, the panel made a strong recommendation in favor of EET in patients with BE high-grade dysplasia and conditional recommendation against EET in BE without dysplasia. The panel made a conditional recommendation in favor of EET in BE low-grade dysplasia; patients with BE low-grade dysplasia who place a higher value on the potential harms and lower value on the benefits (which are uncertain) regarding reduction of esophageal cancer mortality could reasonably select surveillance endoscopy. In patients with visible lesions, a conditional recommendation was made in favor of focal EMR plus ablation over stepwise EMR. In patients with visible neoplastic lesions undergoing resection, the use of either endoscopic mucosal resection or endoscopic submucosal dissection was suggested based on lesion characteristics. CONCLUSIONS: This document provides a comprehensive outline of the indications for EET in the management of BE and related neoplasia. Guidance is also provided regarding the considerations surrounding implementation of EET. Providers should engage in shared decision making based on patient preferences. Limitations and gaps in the evidence are highlighted to guide future research opportunities.

Cryoablation Catheter Used in the Surgical Treatment of Atrial Fibrillation May Treat Chest Tube Pain: Engin Technique.

Postoperative pain after cardiac surgery plays an important role in the patient's recovery process. In particular, pain at the chest tube site can negatively affect the comfort and recovery of these patients. Effective pain control minimizes the risk of many complications. Oral and intravenous analgesics, epidural anesthesia, paravertebral block, and intercostal nerve blockade are used in chest tube pain control. We routinely use the surgical cryoablation method in the presence of atrial fibrillation in the preoperative period of cardiac surgery in our clinic. Here we aimed to describe our method of using the cryoablation catheter for intercostal nerve blockade.

Comparative Effectiveness of Partial Gland Cryoablation Versus Robotic Radical Prostatectomy for Cancer Control.

BACKGROUND AND OBJECTIVE: There is an absence of high-level evidence comparing oncologic endpoints for partial gland ablation, and most series use prostate-specific antigen (PSA) rather than biopsy endpoints. Our aim was to compare oncologic outcomes between partial gland cryoablation (PGC) and radical prostatectomy (RP) for prostate cancer. METHODS: This was a retrospective, single-center analysis of subjects treated with PGC (n = 98) or RP (n = 536) between January 2017 and December 2022 as primary treatment for intermediate-risk (Gleason grade group [GG] 2-3) prostate cancer. Oncologic endpoints included surveillance biopsies per protocol after PGC in comparison to serial PSA testing after RP. The primary outcome was treatment failure, defined as a need for any salvage treatment or development of metastatic disease. Treatment failure and survival analyses were conducted using Cox proportional-hazard regression and Kaplan Meier survival curves. KEY FINDINGS AND LIMITATIONS: After applying the inclusion/exclusion criteria, the PGC (n = 75) and RP (n = 298) groups were compared. PGC patients were significantly older (71 vs 64 yr; p < 0.001), but there were no differences in PSA, biopsy GG, or treatment year between the groups. The PGC group had higher rates of treatment failures at 24 mo (33% vs 11%; p < 0.001) and 48 mo (43% vs 14%; p < 0.001). One PGC patient (2.1%) and one RP patient (0.7%) developed metastases by 48-mo follow-up (p = 0.4). On adjusted analysis, PGC was associated with a higher risk of treatment failure (hazard ratio 4.6, 95% confidence interval 2.7-7.9; p < 0.001). Limitations include observational biases associated with the retrospective study design. CONCLUSIONS: This is the first comparative effectiveness study of cancer control outcomes for PGC versus RP. The results demonstrate an almost fivefold higher risk of treatment failure with PGC during short-term follow-up. PATIENT SUMMARY: We compared cancer control outcomes for patients with intermediate-risk prostate cancer treated with partial gland cryoablation versus radical prostatectomy. We found that partial gland cryoablation had an almost fivefold higher risk of treatment failure. Men with prostate cancer should be counseled regarding this difference in treatment failure.

Percutaneous cryoablation of abdominal wall endometriosis: An analysis of 38 patients.

PURPOSE: The purpose of this study was to evaluate the efficacy of percutaneous cryoablation in the treatment of abdominal wall endometriosis (AWE) nodules. MATERIALS AND METHODS: Thirty-eight women treated for symptomatic AWE nodules with percutaneous cryoablation under ultrasound and computed tomography (CT) guidance between May 2020 and July 2023 were retrospectively included. Pain was estimated using visual analog scale (VAS) and assessed at baseline, three months, six months, and 12 months after percutaneous cryoablation. Baseline VAS score, volume of AWE nodule and magnetic resonance imaging (MRI) features of AWE nodules were compared to those obtained after percutaneous cryoablation. Major complications, if any, were noted. RESULTS: Thirty-eight women with a median age of 35.5 years (interquartile range [IQR]: 32, 39; range: 24-48 years) and a total of 60 AWE nodules were treated. Percutaneous cryoablation was performed under local or regional anesthesia in 30 women (30/38; 79%). Significant decreases between initial median VAS score (7; IQR: 6, 8; range: 3-10) and median VAS score after treatment at three months (0; IQR: 0, 5; range; 0-8) (P < 0.001), six months (0; IQR: 0, 1; range; 0-10) (P < 0.001) and 12 months (0; IQR: 0, 2; range: 0-7) (P < 0.001) were observed. Percutaneous cryoablation resulted in effective pain relief in 31 out of 38 women (82%) at six months and 15 out of 18 women (83%) at 12 months. Contrast-enhanced MRI at six-month follow-up showed a significant decrease in the volume of AWE nodules and the absence of AWE nodule enhancement after treatment by comparison with baseline MRI (P < 0.001). No major complications were reported. CONCLUSION: Percutaneous cryoablation is an effective, minimally invasive intervention for the treatment of AWE nodules that conveys minimal or no morbidity.

The value of cryoablation in orbital surgery.

Aim of this article is to give an overview of the technical background and the advantages of modern devices for different applications of cryoablation in cranio-orbital neurosurgery.The treatment of orbital lesions is complicated by the complex and potentially inapparent anatomy due to retro-orbital fat. With the help of cryoprobes different well-defined lesions such as cavernous venous malformations can be safely and effectively removed thanks to the cryoadhesive effect. Their use has been described in several different approaches including traditional lateral or transcranial orbitotomy but also anterior transconjunctival as well as transnasal endoscopic approaches. Recently, single-use devices were introduced that allow the use of cryosurgery also without the need for large investment or service costs.

Severe epistaxis after posterior nasal nerve ablation requiring surgical intervention: A multi-center case series.

KEY POINTS: Severe epistaxis occurs in 2% of PNN ablation cases, independent of method or device type. Major epistaxis requiring intervention after PNN ablation can occur on average 20 days post-procedure.

Histological evaluation of tissue destruction in mouse tongues caused by cryosurgery.

Introduction: Cryosurgery is recognized as a treatment option for various types of oral lesions. Although cryosurgery is less invasive and easier to perform than surgical treatments, adverse events, such as stomatitis and scarring can occur if the freezing is excessive. There are few studies regarding the effects of cryosurgery on the surrounding soft tissues. Thus, this study investigated the extent of tissue destruction and healing progress in tongues of mice who underwent cryosurgery. Methods: Eight-week-old male BALB/c mice were used. An instrument cooled with liquid nitrogen was lightly touched on the right side of the tongue for 5 s, and a second test was performed 10 s later. Histological evaluation was performed 3, 7, and 14 days after cryosurgery. Blood vessels were evaluated with India ink at 1, 3, 7, 14, and 21 days after cryosurgery. Results: Destruction of the soft tissue spread to the left side of the tongue after 3 days. At 7 days, it was confirmed that the muscle tissue was in the process of repair and was completely repaired at 14 days. Although blood vessels were not confirmed at 3 days, they were visible after seven days and were confirmed at 21 days all over the tongue. Discussion and Conclusion: These results indicated that the tissue destruction caused by cryosurgery was extensive and suggest that the duration and frequency of freezing should be minimized for clinical use. Lay Summary: Cryosurgery is a treatment method for various types of oral lesions. Freezing the lesion causes the tissue to collapse, resulting in its disappearance. Although cryosurgery is less invasive and easier to perform than surgical treatments, adverse events, such as stomatitis and scarring can occur if the freezing is excessive. This study investigated the extent of tissue destruction and healing progress in tongues of mice who underwent cryosurgery.The right side of mice tongues were frozen by an instrument cooled with liquid nitrogen for 5 s, and a second test was performed 10 s later. The tissue destruction was evaluated at 3, 7, and 14 days after freezing. Blood vessels were evaluated with India ink at 1, 3, 7, 14, and 21 days after freezing. Tissue destruction spread to the left side of the tongue after 3 days. At 7 days, it was confirmed that the muscle tissue was in the process of repair and was completely repaired at 14 days. Blood vessel repair was confirmed at 21 days in the throughout tongue. These results indicated that the tissue destruction caused by cryosurgery was large and suggest that the duration and frequency of freezing should be minimized for clinical use.