The history of cryosurgery

Evaluation of a Novel Dermal Cooling System for the Treatment of Benign Pigmented Lesions in Asians

OBJECTIVE

Our study aimed to evaluate the efficacy of this novel dermal cooling system (DCS) in reducing pigmentation in benign pigmented lesions in Asian patients and its potential side effects.

METHODS

It was a prospective open-label single-center study. Asian patients, with the presence of benign pigmented lesions mainly including lentigines, melasma, nevus spilus, ephelides, café au lait, and seborrheic keratosis were recruited for a novel DCS. The DCS provided localized cooling of the epidermal layer below freezing but was less intense than cryotherapy. Each patient received DCS at Week 0 and repeated at 4-week intervals up to 10 sessions. Global aesthetic improvement scores (GAIS) by blinded physicians and subjects were recorded at 2, 6, and 12 months posttreatment follow-up.

RESULTS

Eighty-one patients were recruited with a total of 305 sessions performed and 1716 lesion sites treated. At 2-month posttreatment, 76.5% and 58.6% treatment sites showed obvious to marked improvement respectively and the improvement sustained at 6 and 12 months. Only minor adverse events were reported. Erythema and edema were the most commonly anticipated effects immediately after treatment. The pain was minimal. Postinflammatory hyperpigmentation was only reported in 2.2% (38/1716) treated sites.

CONCLUSION

To our knowledge, this study was the first study to demonstrate that this novel DCS was an effective, safe, and well-tolerated treatment for benign pigmented lesions in Asians.

Tissue Ablation: Applications and Perspectives

Tissue ablation techniques have emerged as a critical component of modern medical practice and biomedical research, offering versatile solutions for treating various diseases and disorders. Percutaneous ablation is minimally invasive and offers numerous advantages over traditional surgery, such as shorter recovery times, reduced hospital stays, and decreased healthcare costs. Intra-procedural imaging during ablation also allows precise visualization of the treated tissue while minimizing injury to the surrounding normal tissues, reducing the risk of complications. Here, the mechanisms of tissue ablation and innovative energy delivery systems are explored, highlighting recent advancements that have reshaped the landscape of clinical practice. Current clinical challenges related to tissue ablation are also discussed, underlining unmet clinical needs for more advanced material-based approaches to improve the delivery of energy and pharmacology-based therapeutics.

Applications of Cryoneurolysis in Chronic Pain Management: a Review of the Current Literature

PURPOSE OF REVIEW

The purpose of this review is to evaluate and summarize the literature investigating cryoneurolysis in the treatment of various chronic pain pathologies.

RECENT FINDINGS

There is an increasing amount of interest in the use of cryoneurolysis in chronic pain, and various studies have investigated its use in lumbar facet joint pain, SI joint pain, post-thoracotomy syndrome, temporomandibular joint pain, chronic knee pain, phantom limb pain, neuropathic pain, and abdominal pain. Numerous retrospective studies and a more limited number of prospective, sham-controlled prospective studies suggest the efficacy of cryoneurolysis in managing these chronic pain pathologies with a low complication rate. However, more blinded, controlled, prospective studies comparing cryoneurolysis to other techniques are needed to clarify its relative risks and advantages.

Cryoanalgesia: Review with Respect to Peripheral Nerve

BACKGROUND

 Cryoanalgesia is a tool being used by interventional radiology to treat chronic pain. Within a certain cold temperature range, peripheral nerve function is interrupted and recovers, without neuroma formation. Cryoanalgesia has most often been applied to the intercostal nerve. Cryoanalgesia has applications to peripheral nerve surgery, yet is poorly understood by reconstructive microsurgeons.

METHODS

 Histopathology of nerve injury was reviewed to understand cold applied to peripheral nerve. Literature review was performed utilizing the PubMed and MEDLINE databases to identify comparative studies of the efficacy of intraoperative cryoanalgesia versus thoracic epidural anesthesia following thoracotomy. Data were analyzed using Fisher's exact and analysis of variance tests. A similar approach was used for pudendal cryoanalgesia.

RESULTS

 Application of inclusion and exclusion criteria resulted in 16 comparative clinical studies of intercostal nerve for this review. For thoracotomy, nine studies compared cryoanalgesia with pharmaceutical analgesia, with seven demonstrating significant reduction in postoperative opioid use or postoperative acute pain scores. In these nine studies, there was no association between the number of nerves treated and the reduction in acute postoperative pain. One study compared cryoanalgesia with local anesthetic and demonstrated a significant reduction in acute pain with cryoanalgesia. Three studies compared cryoanalgesia with epidural analgesia and demonstrated no significant difference in postoperative pain or postoperative opioid use. Interventional radiology targets pudendal nerves using computed tomography imaging with positive outcomes for the patient with pain of pudendal nerve origin.

CONCLUSION

 Cryoanalgesia is a term used for the treatment of peripheral nerve problems that would benefit from a proverbial reset of peripheral nerve function. It does not ablate the nerve. Intraoperative cryoanalgesia to intercostal nerves is a safe and effective means of postoperative analgesia following thoracotomy. For pudendal nerve injury, where an intrapelvic surgical approach may be difficult, cryoanalgesia may provide sufficient clinical relief, thereby preserving pudendal nerve function.

Thermal Characterization and Preclinical Feasibility Verification of an Accessible, Carbon Dioxide-Based Cryotherapy System

To investigate the potential of an affordable cryotherapy device for the accessible treatment of breast cancer, the performance of a novel carbon dioxide-based device was evaluated through both benchtop testing and an in vivo canine model. This novel device was quantitatively compared to a commercial device that utilizes argon gas as the cryogen. The thermal behavior of each device was characterized through calorimetry and by measuring the temperature profiles of iceballs generated in tissue phantoms. A 45 min treatment in a tissue phantom from the carbon dioxide device produced a 1.67 ± 0.06 cm diameter lethal isotherm that was equivalent to a 7 min treatment from the commercial argon-based device, which produced a 1.53 ± 0.15 cm diameter lethal isotherm. An in vivo treatment was performed with the carbon dioxide-based device in one spontaneously occurring canine mammary mass with two standard 10 min freezes. Following cryotherapy, this mass was surgically resected and analyzed for necrosis margins via histopathology. The histopathology margin of necrosis from the in vivo treatment with the carbon dioxide device at 14 days post-cryoablation was 1.57 cm. While carbon dioxide gas has historically been considered an impractical cryogen due to its low working pressure and high boiling point, this study shows that carbon dioxide-based cryotherapy may be equivalent to conventional argon-based cryotherapy in size of the ablation zone in a standard treatment time. The feasibility of the carbon dioxide device demonstrated in this study is an important step towards bringing accessible breast cancer treatment to women in low-resource settings.

A Pilot Randomized Controlled Trial of Vaginal Cryotherapy for the Treatment of Pelvic Floor Myofascial Pain

INTRODUCTION AND HYPOTHESIS

Pelvic floor myofascial pain (PFMP) is a common but underrecognized component of chronic pelvic pain and pelvic floor disorders symptoms with limited, well-studied treatment modalities. Our objective was to determine the effect of vaginal cryotherapy on PFMP with palpation.

METHODS

Following a standardized PFMP screening examination, individuals with a pain score ≥4/10 in ≥1 of four muscle groups were invited to participate in a randomized controlled trial comparing patients undergoing vaginal cryotherapy with controls. Participants in both arms could choose to participate in a single in-office treatment; a 2-week, at-home daily treatment; or both.

RESULTS

Between March 2019 and September 2021, a total of 163 participants were enrolled and randomized: 80 to cryotherapy, and 83 to the control group. Sixty-three (28 cryotherapy; 35 controls) completed in-office treatment and 56 (32 cryotherapy; 24 controls) completed at-home therapy. In the in-office comparison, mean pain scores decreased significantly in both arms: cryotherapy (5.13 vs 4.10; p=0.02) and controls (5.60 vs 4.72; p<0.01), with a similar magnitude of reduction between arms (p=0.75). In the at-home comparison, mean pain scores decreased significantly in the cryotherapy arm (6.34 vs 4.75; p<0.01), and nonsignificantly in the control arm (5.41 vs 4.66; p=0.07), resulting in a nonsignificant difference between arms (p=0.14).

CONCLUSIONS

Pelvic floor myofascial pain with palpation improved following both a single cryotherapy session and 2 weeks of daily cryotherapy. Interestingly, pain scores also improved with room temperature therapy. Whether these findings reflect a therapeutic effect of both cold and room temperature intravaginal therapy or a placebo effect is unclear but should be explored in larger studies.

Split-face study to evaluate efficacy of global cryomodulation for reduction of pain and inflammation after nonablative fractional resurfacing

OBJECTIVES

Cryomodulation, or the delivery of controlled cooling to downregulate inflammatory processes in the skin, has been proposed to mitigate acute side effects following various dermatologic treatments. A new controlled cooling device has been developed to deliver cryomodulation for a range of different indications. In this clinical study, we evaluate the device for the reduction of pain, erythema, and edema following nonablative fractional resurfacing (NAFR).

METHODS

A single-blind, prospective, randomized, split-face study was conducted to assess the efficacy of the controlled dermal cooling device for the reduction of pain, edema, and erythema following nonablative fractional resurfacing with the dual 1550 nm erbium-doped fiber and 1927 nm thulium fiber laser. Subjects were randomized to receive a 10-min controlled cooling treatment to either the left or right side of the face immediately following full face NAFR. Pain ratings were recorded immediately postlaser treatment and immediately postcryomodulation treatment. At follow-up, subjects were surveyed for reduction of side effects and treatment satisfaction. Blinded review of photographs by two physicians was conducted to assess efficacy.

RESULTS

The average pain score for subjects immediately post-NAFR was 5.15. Following cryomodulation, the average pain score on the treatment side was reduced by 69%, to an average of 1.6. The untreated side of the face was reduced by 19%, to an average of 4.2. Overall, 90% of subjects endorsed reduced discomfort. At follow-up, 70% of subjects reported a noticeable improvement in edema and 50% reported a noticeable improvement in erythema between the treatment and control sides. The average subject satisfaction score for the cryomodulation treatment was 4.2. All subjects (100%) indicated that they would elect to undergo the cryomodulation treatment again. Both blinded physician reviewers were successful in identifying the cryomodulation-treated side of the face in 70% of subjects' posttreatment photographs.

CONCLUSIONS

The results of this split-face study support the efficacy of a global cryomodulation device for the reduction of pain, edema, and erythema following NAFR treatment. Cryomodulation was delivered in a simple 10 min procedure and yielded high patient satisfaction.

Forgotten Branch of the Intercostal Nerve: Implication for Cryoablation Nerve Block for Pectus Excavatum Repair

BACKGROUND

We first utilized and reported on the use of cryoanalgesia for postoperative pain control for Nuss procedure in 2016. We hypothesized that postoperative pain control could be optimized if the intercostal nerve anatomy is better understood. To test this hypothesis, human cadavers were dissected to elucidate the intercostal nerve anatomy. Cryoablation technique was modified.

METHODS

Cadaver Study: Adult cadavers were used to visualize the branching patterns of the intercostal nerves. Cryoablation: Posterior to the mid-axillary line for intercostal nerves 4, 5, 6 and 7, main intercostal nerve, lateral cutaneous branch and collateral branch were cryoablated under thoracoscopic view. Verbal pain scores were obtained from patients one day after the procedure.

RESULTS

The study results were obtained during the years 2021 and 2022. Eleven cadavers were dissected. The path of the main intercostal and lateral cutaneous branch lie on the inferior rib surface of the corresponding intercostal nerve. Total of 92 lateral cutaneous branches of the intercostal nerve were dissected and measured as they pierced the intercostal muscle. Most lateral cutaneous branches of the intercostal nerve pierced the intercostal muscle anterior to midaxillary line 78.3%, posterior to midaxillary line 18.5% or on the midaxillary line 3.3%. The collateral branch of the intercostal nerve separated near the spine and traveled along the superior surface of the next inferior rib. Cryoablation: 22 male patients underwent Nuss procedure with cryoanalgesia. Median age of the patients was 15 years (IQR: 2), median Haller index was 3.73 (IQR: 0.85), median pain score (0-10 maximum pain) was 1 (IQR: 1.75).

CONCLUSION

Cryoablation of the intercostal nerve and its two branches improves pain control after a Nuss procedure.

LEVEL OF EVIDENCE

Level 4.

TYPE OF STUDY

Observational study.

Procedural dermatology and its unmet need

Procedural dermatology includes invasive conventional dermatologic surgeries which involve significant use of knife and suture, minimally invasive procedures and device-based procedures. Device-based procedures are the easiest to learn and are less prone to human errors due to automation but can lead to monotony, while conventional surgeries require significant skill, craftsmanship and interest. There has been a recent shift in the approach to procedural dermatology as a therapeutic option with complementary and combination models replacing the conventional hierarchical model in which procedures were last in the step-ladder approach. The demand for both conventional dermatologic surgeries and minimally invasive cosmetic procedures is increasing. Unfortunately, this demand has not been met with adequate supply. Consequently, the number of trained professionals with expertise in these procedures is very limited; they are far outnumbered by unqualified practitioners. A limited number of dermatologic surgeons practicing conventional surgeries has resulted in huge waiting lists for vitiligo surgeries, inappropriate excisions for skin cancers and poor cosmetic outcomes of excisions without proper knowledge of flaps and grafts. Increasingly procedures are being performed by inadequately trained personnel, resulting in complications. There is also an absence of good quality research on the subject of procedural dermatology, which has resulted in a lack of standardisation of various procedures and knowledge about the efficacy of various drug-procedure and procedure-procedure combinations. An increasing variety of gimmicky but costly procedures are being offered to the public without much evidence of efficacy. Individual institutional and broad policy directives are needed to address these issues. Special emphasis is required on formal hands-on procedural dermatology training during residency and beyond it.

Continuous digital hypothermia for prevention and treatment of equine acute laminitis: A practical review

Laminitis is a severely debilitating and life-threatening condition that occurs as a consequence of different primary triggering factors. Continuous digital hypothermia (CDH) is recommended in horses at risk of, or diagnosed with, acute laminitis due to its several physiological and biochemical alterations that may be positive for the prevention and early treatment of the condition, representing a low risk of adverse effects. Modulation of the inflammatory response, profound vasoconstriction, and prevention of tissue damage are the most notable protective effects of cryotherapy on the lamellae. This practical review aims to summarize the published literature evaluating CDH efficacy in the prevention and early treatment of acute laminitis in horses, highlighting the most important clinical findings and discussing the best methods to provide cryotherapy. Nineteen publications evaluated different CDH methods, including the use of commercially available ice boots or fluid bags filled with iced water or crushed ice, as well as alternatives to immersion in ice, e.g., frozen gel packs and a perfused cuff prototype. Although some techniques were effective for cooling and maintaining the hooves below the optimal temperature of 10 °C, relevant limitations such as labor intensiveness, reliance on an ice source and price make its use impractical in some clinical situations. Twelve experimental studies assessed the efficacy of CDH on the prevention or early treatment of laminitis, finding multiple positive effects in terms of clinical improvement, immunological and inflammatory modulation, and histological protection. After the analysis of the literature, the clinical importance of CDH in different stages of laminitis remains clear. However, it also highlights the need for a safer, more user-friendly, and more effective method of cryotherapy that can be used both in a hospital and an ambulatory setting.

Revisiting the Role of Local Cryotherapy for Acne Treatment: A Review and Update

Acne vulgaris is a well-recognized condition among adolescents and adults that adversely affects their quality of life. Local cryotherapy has long been reported to be effective in treating acne vulgaris, inducing a more rapid involution of acne than topical medications. However, the use of cryotherapy has been limited for acne treatment due to several drawbacks, including procedural pain and pigmentary alterations. Currently, newer cryotherapy devices are gaining attention in dermatology due to their ability to monitor and precisely control the target temperature. In this narrative review, a brief history and the latest update on acne cryotherapy will be presented. Additionally, a special emphasis is placed on the role of cryotherapy, alone or in combination with intralesional steroid injections for nodulocystic acne.

Limited cryoablation reduces hospital stay and opioid consumption compared to thoracic epidural analgesia after minimally invasive repair of pectus excavatum

pain following minimally invasive repair of pectus excavatum (MIRPE) is a critical concern that leads to a prolonged hospital stay and high doses of opiates administered to the patients. This study aimed to evaluate the efficacy of intraoperative cryoanalgesia (cryoablation of the intercostal nerves) during MIRPE. We retrospectively analyzed the data of 64 patients who underwent MIRPE and received cryoanalgesia or epidural analgesia between January 2019 and January 2021. The oral morphine milligram equivalent (MME) was used to calculate the dosage of opioid agents. The median age was 15 years (range, 4-33 years). The median postoperative hospital stay was 4 days (range, 2-6 days), with a median oral MME consumption of 45 mg (ranging from 0 to 1360 mg). Cryoanalgesia was performed in 38 patients, and epidural analgesia was administered to the remaining 26 patients. The cryoanalgesia group had a significantly lesser pain score, shorter postoperative hospital stay and lower oral MME consumption than the epidural analgesia group (5 vs 2; P < .001, 3 days vs 5 days; P < .001, 19 mg vs 634 mg; P < .001). Cryoanalgesia appears to reduce postoperative hospital stay and opioid consumption compared with epidural analgesia. The outcomes of this study indicate that cryoanalgesia might be a safe and effective method for pain control following MIRPE.

Systematic Review of Focal and Salvage Cryotherapy for Prostate Cancer

Cryotherapy is one of the recognised ablative modalities for both primary and salvage therapy for prostate cancer. It presents an alternative, less invasive treatment for an organ-confined disease, improved preservation of surrounding tissue and a more suitable option for patients who are unfit for radical prostatectomy. Nevertheless, the currently available literature is relatively too scarce to provide definite conclusions regarding the treatment outcomes in cryotherapy. The present study aimed to review current oncological and survival outcomes in cryotherapy for primary and recurrent prostate cancer. Furthermore, this study aimed to establish the complications and functional outcomes of cryotherapy for prostate cancer. A literature search was performed on the PubMed, Cochrane and Google Scholar databases. Current guidelines and recommendations from the European Association of Urology were also reviewed. The search keywords used included ‘Cryotherapy, Prostate Cancer’, ‘Cryoablation, Prostate Cancer’ and ’Cryosurgery, Focal Prostate Cancer’. Truncations and Boolean operators were used with the keywords. All relevant studies from after 2015, including abstracts and non-English research assessing oncological and functional outcomes and complications, were included. Twenty-six studies consisting of 11,228 patients were reviewed. Fifteen studies assessed the outcomes of primary cryotherapy, whereas 11 studies reported the outcomes in salvage therapy. The patient's age ranged 55-85 years, and the pre-procedural prostate-specific antigen (PSA) ranged 0.01-49.33 ng/mL. A total of 2031 patients were classified to be at low risk, 2,995 were at moderate risk and 253 were at high risk on the D’Amico prostate cancer risk classification system. Follow-ups ranged from 9.0 to 297.6 months. The disease-specific survival rate was 65.5%-100.0%, overall survival was 61.3%-99.1%, the PSA nadir was 0.01-2.63 ng/mL and the overall biochemical recurrence rate was 15.4%-62.0%. The complications included erectile dysfunction (3.7%-88.0%), urinary retention (2.13%-25.30%) and bladder neck stricture/stenosis (3.0%-16.7%). The functional assessment showed a mixture of improved, unchanged or worsened post-procedural outcomes in primary therapy. This systematic review did not find significant differences in the cancer-specific, overall and biochemical-free survival rate between the primary and salvage cryotherapy cohorts. The most common complications encountered in both cohorts were erectile dysfunction, urinary incontinence, lower urinary tract/bladder neck stricture and infection. More prospective and double-arm studies are critically needed to provide guidance on the careful selection of patient cohorts for cryotherapy, whether for curative or salvage intent.

Cryoneurolysis for Digital Neuralgia in Professional Baseball Players: A Case Series

Background

Thumb injuries are common in baseball players and can sometimes be challenging to effectively manage. A subset of patients experience failed nonoperative management yet do not have a clear indication for surgery. Cryoneurolysis or cryoanalgesia is a form of neuromodulation for pain that has been approved by the US Food and Drug Administration; it has been used safely and effectively on a variety of peripheral nerves. The mechanism of action involves percutaneous introduction of a small probe under local anesthetic to nerve tissue using ultrasound guidance. The probe is then cooled to -88°C using nitrous oxide, which results in secondary Wallerian degeneration. Axonal and myelin regeneration occurs completely in 3 to 6 months.

Purpose

To describe a nonsurgical approach to refractory digital neuralgia using cryoneurolysis in a series of professional baseball players.

Study Design

Case series; Level of evidence, 4.

Methods

Included were 3 professional baseball players, each presenting with thumb pain in his top batting hand refractory to nonoperative modalities. Visualization of the superficial radial sensory and ulnar digital nerves was obtained using ultrasound. The skin was prepared in sterile fashion. A 22-gauge, 1.5-inch (3.8-cm) needle was then advanced using ultrasound guidance, and local anesthetic was applied. Both treatment sites were marked using a skin marker. Cryoneurolysis was performed using a 5-mm tip, and 60-second treatment cycles were performed at each site. Each of the cycles resulted in a roughly 5 × 7-mm lesion visible as hypoechoic signal.

Results

All 3 players endorsed significant and prolonged relief and were able to return to an elite level of play.

Conclusion

Study findings indicated marked efficacy and safety of using cryoneurolysis of the ulnar digital nerve and the superficial radial sensory nerve in a small group of elite baseball players with refractory digital neuralgia.

Split-face comparative trial of 785-nm picosecond neodymium:yttrium-aluminum-garnet laser and precision cryotherapy combination treatment for facial benign pigmented lesions

Cryotherapy (or cryosurgery) has been performed to treat various skin lesions in the field of dermatology; however, to the best of our knowledge, no study has investigated its efficacy and safety for benign pigmented lesions. Therefore, we conducted a split-face study to evaluate the efficacy and safety of cryotherapy in the treatment of benign pigmented lesions. A total of five subjects were included. Picosecond laser therapy was performed to treat the whole face and cryotherapy for half the face. Four weeks after completing the treatment sessions, patients showed more clinical improvement on the laser and cryotherapy combination treatment side than on the laser-only side, with no adverse events. Our study demonstrated that cryotherapy is a potential adjuvant therapeutic modality for benign pigmented lesions.

Cryotherapy Techniques: Best Protocols to Support the Foot in Health and Disease

Treatment of equine laminitis continues to be a challenge despite recent advancements in knowledge of the pathophysiology of laminitis. With more evidence supporting its use, distal limb hypothermia or cryotherapy has become a standard of care for both prevention of laminitis and treatment of the early stages of acute laminitis. Recent studies have demonstrated that cryotherapy reduces the severity of sepsis-related laminitis and hyperinsulinemic laminitis in experimental models and reduces the incidence of laminitis in clinical colitis cases. This article reviews the recent literature supporting the use of distal limb cryotherapy in horses.

Phonosurgery: A review of current methodologies

Cold-steel has served as the gold standard modality of phonosurgery for most of its history. Surgical laser technology has revolutionized this field with its wide use of applications. Additional modalities have also been introduced such as coagulative lasers, photodynamic therapy, and cryotherapy. This review will compare the surgical modalities of cold steel, surgical lasers, phototherapy and cryotherapy. The mechanism of action, tissue effects and typical uses will be addressed for each modality.

Percutaneous cryoneurolysis for acute pain management: current status and future prospects

Introduction: Conventional nerve blocks utilize local anesthetic drugs to provide pain relief for hours or days following surgery or trauma. However, postoperative and trauma pain can last weeks or months. Ultrasound-guided percutaneous cryoneurolysis is an anesthetic modality that offers substantially longer pain relief compared to local anesthetic-based nerve blocks.Areas covered: In this review, we discuss the history, mechanism of action, and use of ultrasound-guided percutaneous cryoneurolysis by anesthesiologists in the setting of acute pain management.Expert opinion: Ultrasound-guided percutaneous cryoneurolysis offers the potential to provide weeks or months of pain relief following surgery or trauma. Compared to continuous local anesthetic-based peripheral nerve blocks, currently the gold standard for providing long duration postoperative analgesia, cryoneurolysis has benefits that include: 1) longer duration measured in weeks or months rather than days; 2) no external reservoir of local anesthetic to be carried by the patient; 3) no risk of infection; and 4) no risk of catheter dislodgement. However, cryoneurolysis can induce a prolonged motor block in addition to the sensory block, decreasing the appropriate indications to those in which potential sensory and motor deficits are acceptable. Additionally, cryoneurolysis of multiple nerves can have a substantial time requirement relative to conventional nerve blocks.

History of dermatology: the study of skin diseases over the centuries

The study of skin, the science of dermatology, has undergone significant transformations throughout the centuries. From the first descriptions of skin diseases in Egyptian papyri and in Hippocratic writings to the first treatises on dermatology, important individuals and discoveries have marked the specialty. In the 18th and 19th centuries, the specialty consolidated itself as a field of medical study based on the first classifications of dermatoses, diagnostic methods, and drug treatments. In the 20th century, the scientific and technological revolution transformed dermatological practice, incorporating new therapeutic resources, as well as surgical and aesthetic procedures. In the face of such a vigorous process, it is important to provide a historical synthesis for the medical community to recognize and understand the origins that supported one of the most relevant specialties in the current medical scenario.

Image-guided Cryotherapy for Musculoskeletal Tumors

BACKGROUND

This article represents a review of the use of image-guided cryotherapy in the treatment of musculoskeletal tumor lesions. Cryotherapy is able to induce a lethal effect on cancer cells through direct and indirect mechanisms. In this manuscript, we combined our experience with that of other authors who have published on this topic in order to provide indications on when to use cryotherapy in musculoskeletal oncology.

DISCUSSION

Image-Guided percutaneous cryotherapy is a therapeutic method now widely accepted in the treatment of patients with musculoskeletal tumors. It can be used both for palliative treatments of metastatic bone lesions and for the curative treatment of benign bone tumors, such as osteoid osteoma or osteoblastoma. In the treatment of bone metastases, cryotherapy plays a major role in alleviating or resolving disease-related pain, but it has also been demonstrated that it can have a role in local disease control. In recent years, the use of cryotherapy has also expanded for the treatment of both benign and malignant soft tissue tumors.

CONCLUSION

Percutaneous cryotherapy can be considered a safe and effective technique in the treatment of benign and malignant musculoskeletal tumors. Cryotherapy can be considered the first option in benign tumor lesions, such as osteoid osteoma, and a valid alternative to radiofrequency ablation. In the treatment of painful bone metastases, it must be considered secondarily to other standard treatments (radiotherapy, bisphosphonate therapy, and chemotherapy) when they are no longer effective in controlling the disease or when they cannot be repeated (for example, radiotherapy).

Updates in Cryotherapy for Barrett's Esophagus

Cryotherapy is an ablation modality relying on freeze-thaw cycles to promote cell death through intracellular ice crystal formation, ischemia, and apoptosis. Currently, 2 different cryotherapy systems are available for esophageal use. The first is cryospray ablation, which involves repetitive applications of liquid nitrogen. The second system, cryoballoon ablation, freezes the esophageal mucosa with liquid nitrous oxide using a compliant balloon. To date, studies have shown that cryotherapy is an effective and safe method for eradicating Barrett's esophagus; however, larger prospective series with longer follow-up are warranted to determine the clinical utility of cryotherapy in the treatment of Barrett's esophagus.

Cryoneurolysis and Percutaneous Peripheral Nerve Stimulation to Treat Acute Pain

Two regional analgesic modalities currently cleared by the U.S. Food and Drug Administration hold promise to provide postoperative analgesia free of many of the limitations of both opioids and local anesthetic-based techniques. Cryoneurolysis uses exceptionally low temperature to reversibly ablate a peripheral nerve, resulting in temporary analgesia. Where applicable, it offers a unique option given its extended duration of action measured in weeks to months after a single application. Percutaneous peripheral nerve stimulation involves inserting an insulated lead through a needle to lie adjacent to a peripheral nerve. Analgesia is produced by introducing electrical current with an external pulse generator. It is a unique regional analgesic in that it does not induce sensory, motor, or proprioception deficits and is cleared for up to 60 days of use. However, both modalities have limited validation when applied to acute pain, and randomized, controlled trials are required to define both benefits and risks.

Exploring the Proteomic Alterations from Untreated and Cryoablation and Irradiation Treated Giant Cell Tumors of Bone Using Liquid-Chromatography Tandem Mass Spectrometry

Giant cell tumors of bone (GCT) are benign tumors that show a locally aggressive nature and affect bones' architecture. Recently, cryoablation and irradiation treatments have shown promising results in GCT patients with faster recovery and less recurrence and metastasis. Therefore, it became a gold standard surgical treatment for patients. Hence, we have compared GCT-untreated, cryoablation, and irradiation-treated samples to identify protein alterations using high-frequency liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). Our label-free quantification analysis revealed a total of 107 proteins (p < 0.01) with 26 up-regulated (< 2-folds to 5-fold), and 81 down-regulated (> 0.1 to 0.5 folds) proteins were identified from GCT-untreated and treated groups. Based on pathway analysis, most of the identified up-regulated proteins involved in critical metabolic functions associated with tumor proliferation, angiogenesis, and metastasis. On the other hand, the down-regulated proteins involved in glycolysis, tumor microenvironment, and apoptosis. The observed higher expressions of matrix metalloproteinase 9 (MMP9) and TGF-beta in the GCT-untreated group associated with bones' osteolytic process. Interestingly, both the proteins showed reduced expressions after cryoablation treatment, and contrast expressions identified in the irradiation treated group. Therefore, these expressions were confirmed by immunoblot analysis. In addition to these, several glycolytic enzymes, immune markers, extracellular matrix (ECM), and heat shock proteins showed adverse expressions in the GCT-untreated group were identified with favorable regulations after treatment. Therefore, the identified expression profiles will provide a better picture of treatment efficacy and effect on the molecular environment of GCT.

Interventional Cryoneurolysis: What Is the Same, What Is Different, What Is New?

Cryoneurolysis is the deliberate application of cold temperatures to nerves for therapeutic purposes. The idea of treating pain with this technique is thousands of years old and has evolved over time through the application of surgical techniques, nerve stimulation and/or landmark guidance, and through device development. Recent integration of the interventional radiology skill set to this space has unlocked a myriad of opportunities-primarily through a unique ability to percutaneously access deep structures in the body with accuracy and precision, and the capacity to monitor ablation zones. Understanding of the specific neurohistological process that follows targeted cryoneurolysis leads to new options for treating patients in pain without drugs and opens doors for the potential modification of a wide array of disease states.

Cryoablation and Immunotherapy: An Enthralling Synergy to Confront the Tumors

Treatment of solid tumors by ablation techniques has gained momentum in the recent years due to their technical simplicity and reduced morbidity as juxtaposed to surgery. Cryoablation is one of such techniques, known for its uniqueness to destroy the tumors by freezing to lethal temperatures. Freezing the tumor locally and allowing it to remain in situ unleashes an array of tumor antigens to be exposed to the immune system, paving the way for the generation of anti-tumor immune responses. However, the immune responses triggered in most cases are insufficient to eradicate the tumors with systemic spread. Therefore, combination of cryoablation and immunotherapy is a new treatment strategy currently being evaluated for its efficacy, notably in patients with metastatic disease. This article examines the mechanistic fabric of cryoablation for the generation of an effective immune response against the tumors, and various possibilities of its combination with different immunotherapies that are capable of inducing exceptional therapeutic responses. The combinatorial treatment avenues discussed in this article if explored in sufficient profundity, could reach the pinnacle of future cancer medicine.

Cryotherapy in the management of premalignant and malignant conditions of the esophagus

Endoscopic cryotherapy is a relatively new thermal ablative modality used for the treatment of neoplastic lesions of the esophagus. It relies on cycles of rapid cooling and thawing to induce tissue destruction with a cryogen (liquid nitrogen or carbon dioxide) leading to intra and extra-cellular damage. Surgical treatment was once considered the standard therapeutic intervention for neoplastic diseases of the esophagus and is associated with considerable rates of morbidity and mortality. Several trials that evaluated cryotherapy in Barrett’s esophagus (BE) associated neoplasia showed reasonable efficacy rates and safety profile. Cryotherapy has also found applications in the treatment of esophageal cancer, both for curative and palliative intent. Cryotherapy has also shown promising results as salvage therapy in cases refractory to radiofrequency ablation treatment. Cryoballoon focal ablation using liquid nitrogen is a novel mode of cryogen delivery which has been used for the treatment of BE with dysplasia and squamous cell carcinoma. Most common side effects of cryotherapy reported in the literature include mild chest discomfort, esophageal strictures and bleeding. In conclusion, cryotherapy is an effective and safe method for the treatment of esophageal neoplastic processes, ranging from early stages of low grade dysplasia to esophageal cancer.

Primary cryotherapy for localised or locally advanced prostate cancer

BACKGROUND

Traditionally, radical prostatectomy and radiotherapy with or without androgen deprivation therapy have been the main treatment options to attempt to cure men with localised or locally advanced prostate cancer. Cryotherapy is an alternative option for treatment of prostate cancer that involves freezing of the whole prostate (whole gland therapy) or only the cancer (focal therapy), but it is unclear how effective this is in comparison to other treatments.

OBJECTIVES

To assess the effects of cryotherapy (whole gland or focal) compared with other interventions for primary treatment of clinically localised (cT1-T2) or locally-advanced (cT3) non-metastatic prostate cancer.

SEARCH METHODS

We updated a previously published Cochrane Review by performing a comprehensive search of multiple databases (CENTRAL, MEDLINE, EMBASE), clinical trial registries (ClinicalTrials.gov, World Health Organization International Clinical Trials Registry Platform) and a grey literature repository (Grey Literature Report) up to 6 March 2018. We also searched the reference lists of other relevant publications and conference proceedings. We applied no language restrictions.

SELECTION CRITERIA

We included randomised or quasi-randomised trials comparing cryotherapy to other interventions for the primary treatment of prostate cancer.

DATA COLLECTION AND ANALYSIS

Two independent reviewers screened the literature, extracted data, and assessed risk of bias. We performed statistical analyses using a random-effects model and interpreted them according to the Cochrane Handbook for Systematic Reviews of Interventions. We rated the quality of evidence (QoE) according to the GRADE approach.

MAIN RESULTS

We included only one comparison of whole gland cryotherapy versus external beam radiotherapy, which was informed by two trials with a total of 307 randomised participants. The median age of the included studies was around 70 years. The median follow-up of included studies ranged from 100 to 105 months.Primary outcomes: we are uncertain about the effect of whole gland cryotherapy compared to radiation therapy on time to death from prostate cancer; hazard ratio (HR) of 1.00 (95% confidence interval (CI) 0.11 to 9.45; 2 trials, 293 participants; very low QoE); this would correspond to zero fewer death from prostate cancer per 1000 men (95% CI 85 fewer to 520 more). We are equally uncertain about the effect of quality of life-related urinary function and bowel function (QoL) at 36 months using the UCLA-Prostate Cancer Index score for which higher values (range: 0 to 100) reflect better quality of life using minimal clinically important differences (MCID) of 8 and 7 points, respectively; mean difference (MD) of 4.4 (95% CI -6.5 to 15.3) and 4.0 (95% CI -73.96 to 81.96), respectively (1 trial, 195 participants; very low QoE). We are also uncertain about sexual function-related QoL using a MCID of 8 points; MD of -20.7 (95% CI -36.29 to -5.11; 1 trial, 195 participants; very low QoE). Lastly, we are uncertain of the risk for major adverse events; risk ratio (RR): 0.91 (95% CI 0.47 to 1.78; 2 trials, 293 participants; very low QoE); this corresponds to 10 fewer major adverse events per 1000 men (95% CI 58 fewer to 86 more).

SECONDARY OUTCOMES

we are very uncertain about the effects of cryotherapy on time to death from any cause (HR 0.99, 95% CI 0.05 to 18.79; 2 trials, 293 participants; very low QoE), and time to biochemical failure (HR 2.15, 95% CI 0.07 to 62.12; 2 trials, 293 participants; very low QoE). Rates of secondary interventions for treatment failure and minor adverse events were either not reported in the trials, or the data could not be used for analyses.We found no trials that compared whole gland cryotherapy or focal cryotherapy to other treatment forms such as radical surgery, active surveillance, watchful waiting or other forms of radiotherapy.

AUTHORS' CONCLUSIONS

Based on very low quality evidence, primary whole gland cryotherapy has uncertain effects on oncologic outcomes, QoL, and major adverse events compared to external beam radiotherapy. Reasons for downgrading the QoE included serious study limitations, indirectness due to the use of lower doses of radiation in the comparison group than currently recommended, and serious or very serious imprecision.

The renaissance of anti-neoplastic immunity from tumor cell demise

Cancer therapies can temporarily reduce tumor burdens by inducing malignant cell death. However, cancer cure is still far from realization because tumors often gain resistance to current treatment and eventually relapse. Accumulating evidence suggests that successful cancer interventions require anti-tumor immunity. Therapy-induced cell stress responses ultimately result in one or more cell death modalities, including apoptosis, autophagy, necroptosis, and pyroptosis. These irreversible dying processes are accompanied by active or passive release of cell death-associated molecular patterns (CDAMPs), which can be sensed by corresponding pattern recognition receptors (PRR) on tumor-infiltrating immune cells. This crosstalk with the immune system can reawaken immune surveillance in the tumor microenvironment (TME). This review focuses on immune-modulatory properties of anti-cancer regimens and CDAMP-mediated communications between cell stress responses and the immune contexture of TME. In addition, we describe how immunogenic cell death can elicit strong and durable anti-tumor immune responses.

Immunotherapy Plus Cryotherapy: Potential Augmented Abscopal Effect for Advanced Cancers

Since the 1920s the gold standard for treating cancer has been surgery, which is typically preceded or followed with chemotherapy and/or radiation, a process that perhaps contributes to the destruction of a patient’s immune defense system. Cryosurgery ablation of a solid tumor is mechanistically similar to a vaccination where hundreds of unique antigens from a heterogeneous population of tumor cells derived from the invading cancer are released. However, releasing tumor-derived self-antigens into circulation may not be sufficient enough to overcome the checkpoint escape mechanisms some cancers have evolved to avoid immune responses. The potentiated immune response caused by blocking tumor checkpoints designed to prevent programmed cell death may be the optimal treatment method for the immune system to recognize these new circulating cryoablated self-antigens. Preclinical and clinical evidence exists for the complementary roles for Cytotoxic T-lymphocyte-associated protein (CTLA-4) and PD-1 antagonists in regulating adaptive immunity, demonstrating that combination immunotherapy followed by cryosurgery provides a more targeted immune response to distant lesions, a phenomenon known as the abscopal effect. We propose that when the host’s immune system has been “primed” with combined anti-CTLA-4 and anti-PD-1 adjuvants prior to cryosurgery, the preserved cryoablated tumor antigens will be presented and processed by the host’s immune system resulting in a robust cytotoxic CD8⁺ T-cell response. Based on recent investigations and well-described biochemical mechanisms presented herein, a polyvalent autoinoculation of many tumor-specific antigens, derived from a heterogeneous population of tumor cancer cells, would present to an unhindered yet pre-sensitized immune system yielding a superior advantage in locating, recognizing, and destroying tumor cells throughout the body.

Cryotherapy for Intra- and Perianal High-Grade Squamous Intraepithelial Lesions in HIV-Positive Men who have Sex with Men

BACKGROUND

Available treatment options for anal high-grade squamous intraepithelial lesions (HSIL) in HIV-positive men who have sex with men (MSM) are limited by low response rates and frequent recurrences. Cryotherapy is an established therapeutic option for several pre-malignant skin disorders.

METHODS

This retrospective, non-randomized study included HIV-positive MSM who received intra- and/or perianal HSIL cryotherapy treatment between 30 December 2008 and 23 April 2015. Cryotherapy was applied in sessions 4-6 weeks apart for a maximum of five sessions. Patients received a follow-up high-resolution anoscopy (HRA) to assess treatment response. Complete and partial treatment responders were followed-up after 6 months and then every 6-12 months to investigate recurrent HSILs.

RESULTS

Of 64 patients [median age 48 years; interquartile range (IQR) 42-56] included in the study, six were lost to follow-up. In total, 35 (60%) of 58 patients responded to treatment. Of 64 patients, 31 (48%) reported one or more side effects, of which anal pain or tenderness and mild blood loss were reported most frequently. A total of 19 patients who responded to cryotherapy were adequately followed-up for over 18 months, of whom 13 (68%) had recurrent HSILs.

CONCLUSION

Cryotherapy is capable of clearing HSIL in HIV-positive MSM, and treatment success rates are comparable with those reported for current treatment modalities. The treatment is well tolerated, and side effects are relatively mild. Future studies should therefore compare the efficacy and tolerability of cryotherapy with those of current treatment modalities in randomized controlled trials.

Targeted Ablative Therapies for Prostate Cancer

Men diagnosed with low- to intermediate-risk, clinically localized prostate cancer (PCa) often face a daunting and difficult decision with respect to treatment: active surveillance (AS) or radical therapy. This decision is further confounded by the fact that many of these men diagnosed, by an elevated PSA, will have indolent disease and never require intervention. Radical treatments, including radical prostatectomy and whole-gland radiation, offer greater certainty for cancer control, but at the risk of significant urinary and/or sexual morbidity. Conversely, AS preserves genitourinary function and quality of life in exchange for burdensome surveillance and the psychological impact of living with cancer.

Efficacy and Safety of Three Cryotherapy Devices for Wart Treatment: A Randomized, Controlled, Investigator-Blinded, Comparative Study

INTRODUCTION

Cutaneous warts are common skin lesions, caused by human papillomavirus. For years, liquid nitrogen is the cryogen of choice for wart treatment. Alternatively, several cryogenic devices for home treatment are commercially available. The present trial assessed efficacy and safety of a novel nitrous oxide-based cryogenic device for home use (EndWarts Freeze^® in Europe, Compound W^® Nitro-Freeze in the USA).

METHODS

This investigator-blinded, controlled, randomized study compared the nitrous oxide device (test product) with a dimethylether propane-based product (Wartner^®; comparator 1). Subjects with common or plantar warts (50/50 ratio) were randomized into two groups (n = 58, test product; n = 40, comparator 1). Sequentially, an extra treatment arm (n = 40) was added to compare with a dimethylether-based product with metal nib (Wortie^®; comparator 2). Main objective implied comparison of the percentage cured subjects after one to maximum three treatments. Efficacy and safety was evaluated by a blinded investigator.

RESULTS

After a maximum of three applications, a significantly (p = 0.001) higher cure rate of 70.7% (Intention-to-Treat analysis) was observed with test product versus 46.2% (comparator 1) and 47.5% (comparator 2). Almost three times more subjects were cured after 1 test product application (29.3%), versus comparator 1 (10.4%) and comparator 2 (12.5%). Reported side effects were transient and typical of cryotherapy. All treatments were well-tolerated.

CONCLUSION

The superior cure rates for the test product versus two comparators can be explained by its design. Combination of nitrous oxide (cooling agent), the specific activation method (holding the liquid coolant in the cap), and skin-conforming polyurethane foam, results in higher cooling efficiency (- 80 °C) and more effective wart freezing. This trial demonstrated that the nitrous oxide device is a safe, user-friendly and effective wart treatment for home use, comparing favourably to dimethylether (propane) devices with higher freezing temperature, regardless of the applicator type.

FUNDING

Oystershell Laboratories.

TRIAL REGISTRATION

Clinicaltrials.gov identifier, NCT03129373.

Cervical Precancer Treatment in Low- and Middle-Income Countries: A Technology Overview

Cervical cancer is the fourth leading cause of cancer-related death in women worldwide, with 90% of cases occurring in low- and middle-income countries (LMICs). There has been a global effort to increase access to affordable screening in these settings; however, a corresponding increase in availability of effective and inexpensive treatment modalities for ablating or excising precancerous lesions is also needed to decrease mortality. This article reviews the current landscape of available and developing technologies for treatment of cervical precancer in LMICs. At present, the standard treatment of most precancerous lesions in LMICs is gas-based cryotherapy. This low-cost, effective technology is an expedient treatment in many areas; however, obtaining and transporting gas is often difficult, and unwieldy gas tanks are not conducive to mobile health campaigns. There are several promising ablative technologies in development that are gasless or require less gas than conventional cryotherapy. Although further evaluation of the efficacy and cost-effectiveness is needed, several of these technologies are safe and can now be implemented in LMICs. Nonsurgical therapies, such as therapeutic vaccines, antivirals, and topical applications, are also promising, but most remain in early-stage trials. The establishment of evidence-based standardized protocols for available treatments and the development and introduction of novel technologies are necessary steps in overcoming barriers to treatment in LMICs and decreasing the global burden of cervical cancer. Guidance from WHO on emerging treatment technologies is also needed.

Image-guided focal therapy for prostate cancer

The adoption of routine prostate specific antigen screening has led to the discovery of many small and low-grade prostate cancers which have a low probability of causing mortality. These cancers, however, are often treated with radical therapies resulting in long-term side effects. There has been increasing interest in minimally invasive focal therapies to treat these tumors. While imaging modalities have improved rapidly over the past decade, similar advances in image-guided therapy are now starting to emerge--potentially achieving equivalent oncologic efficacy while avoiding the side effects of conventional radical surgery. The purpose of this article is to review the existing literature regarding the basis of various focal therapy techniques such as cryotherapy, microwave, laser, and high intensity focused ultrasound, and to discuss the results of recent clinical trials that demonstrate early outcomes in patients with prostate cancer.

Wallerian degeneration and recovery of motor nerves after multiple focused cold therapies

Introduction: A device has been developed to apply freezing temperatures to temporarily impede nerve conduction, resulting in inhibition of voluntary skeletal muscle contraction. This device was designed as an alternative to the neurotoxins usually used to treat movement disorders. Methods: We evaluated the effects of single and 3 repeat treatments with a cryoprobe device (−55°C) on a sciatic nerve rat model. Long-term effects of repeated treatment were evaluated through assessments of physiological function and histological analysis. Results: There was consistent weakening of physiological function after each treatment, with recovery of normal function by 8 weeks posttreatment. Histological findings showed axonal degeneration with no disruption to the epineurial or perineurial structures. Progressive axonal regeneration was followed by normal recovery by 24 weeks post-treatment. Conclusions: Low-temperature treatment of motor nerves did not result in permanent or long-term changes to nerve function or structure. Muscle Nerve 51: 268–275, 2015

Reduction in muscular motility by selective focused cold therapy: a preclinical study

Application of freezing temperatures to the temporal branch of the facial nerve can temporarily inhibit motor nerve conduction, resulting in inhibition of voluntary contraction of the frontalis and glabella muscle groups. This feasibility study demonstrates the reduction in motility of muscle groups through application of low temperatures to nerves in a rat model. Twenty-seven adult female Sprague–Dawley rats received cryotreatment to the tibial nerve of the hind limb, and the contralateral limb was left untreated as a negative control. The use of a cold temperature application (−59 ± 8 °C for 60 s) onto the rat tibial nerve resulted in temporary reduction of physiological function of the hind limb. Histological observations of the nerve revealed demyelination and axonal degeneration by 2 weeks post-treatment followed by complete axonal regeneration and remyelination at 16 weeks. Application of low temperatures to peripheral motor nerves resulted in temporary denervation and loss of function of the treated hind limb. Low temperature treatment on motor nerves did not result in any permanent or long-term changes to function and structure of the nerves.