Vocal Fold Healing after Laser Cordectomy with Adjuvant Cryotherapy

Cryotherapy Modifies Extracellular Matrix Expression of Vocal Fold in Rat Models

OBJECTIVES

Vocal fold (VF) scarring is the major cause of voice disorders. Cryotherapy is an effective anti-scarring therapy for skin lesions. The aim of this study was to explore the anti-scarring potential of cryotherapy in vocal folds.

METHODS

The extracellular matrix (ECM) mRNA expression of cryotherapy on normal VF tissue and the histologic results of cryotherapy on vocal fold healing were studied. Fifteen rats were introduced cryotherapy on the normal VF bilaterally and were harvested for real-time polymerase chain reaction (RT-PCR) analysis for collagen I, collagen III, TGFβ1, decorin, fibronectin and HAS1 at 1 day, 3 days and 7 days. Ten rats were unilaterally injured by stripping lamina propria and immediately treated with or without cryotherapy and were harvested at 2 months for histological and immunohistochemical analysis.

RESULTS

Regenerative effect of cryotherapy was validated of ECM gene expression. Histological and immunohistochemical analysis showed significantly increased hyaluronan, decreased collagen, and increased decorin deposition in injury-cryotherapy cohort compared with injury control cohort and normal control cohort.

CONCLUSIONS

Cryotherapy may provide an optimal environment for vocal fold tissue regeneration. The results of the present investigation suggest that cryotherapy has therapeutic potential in prevention and treatment of vocal fold scarring.

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.

High-speed videolaryngoscopy in early glottic carcinoma patients following transoral CO2 LASER cordectomy

PURPOSE

To compare high-speed videolaryngoscopy (HSV) findings, like open quotient (OQ), vocal fold vibratory onset delay (VFVOD), amplitude symmetry index (ASI) and phase symmetry index (PSI), after 6 months of cordectomy with that after 1 year, and to compare later with the control group.

METHODS

Retrospective analysis of HSV recordings of 33 patients of early glottic carcinoma after cordectomy was performed after 6 months and 1 year of cordectomy with the help of videokymogram and digital kymogram. The control group of ten individuals was selected from patients who came to hospital with complaints other than larynx. The comparison was done for different types of cordectomy separately.

RESULTS

The mean of OQ, VFVOD, ASI and PSI was found to be significantly higher after 6-month follow-up than after 1-year follow-up, the later was in turn found to be significantly higher than that of the control group, for type II and III cordectomy. The mean of OQ, VFVOD, ASI and PSI for other types of cordectomy also showed similar results, but the significance was not calculated due to less sample size.

CONCLUSION

There was significant improvement in OQ, VFVOD, PSI and ASI following CO₂ LASER cordectomy after 1 year of follow-up, making it a good management option for early glottic carcinoma. The ability of the HSV to measure variations in the vocal cord vibration, following cordectomy, was well established by this study.

Subglottic Cryotherapy: A Pilot Study in New Zealand White Rabbits

To describe proof of concept and pilot data for a cryotherapy application in the subglottis in a rabbit airway model. Four New Zealand white rabbits (3 experimental, 1 control) underwent general anesthesia and laryngoscopy and bronchoscopy. Experimental animals had cryotherapy applied with a direct contact 1.9-mm cryoprobe. Animals were euthanized at days 0, 2, and 6 posttreatment. Histologic changes were assessed in the treated subglottic tissues. This preliminary work has demonstrated that, with early cryogenic injury in the subglottis, there is mild mucosal epithelial injury associated with submucosal edema, acute inflammatory infiltrate, and degeneration of venule endothelial cells. Mucosal epithelial repair and resolution of the inflammatory response appear to be relatively rapid. We hope that this may provide a foundation to further explore cryotherapy as a primary or adjuvant treatment option for pediatric subglottis stenosis.

The effects of cryotherapy on vocal fold healing in a rabbit model

OBJECTIVES/HYPOTHESIS

Cryotherapy has been shown to be a scarless treatment modality for dermal lesions; however, there are limited data addressing the effect of cryotherapy on vocal fold tissue. The aim of this study was to clarify the effectiveness of cryotherapy for prevention of postsurgical vocal fold scarring.

STUDY DESIGN

Prospective animal study in rabbits.

METHODS

The lamina propria of 20 rabbit vocal folds was bilaterally stripped, followed by randomized unilateral cryotherapy. Five larynges were harvested for real-time polymerase chain reaction (RT-PCR) analysis at 1 day, 3 days, and 7 days postinjury. The remaining five were harvested for histologic analysis at 3 months. Images of the healing phase were recorded by laryngoscopy. Analyses of RT-PCR for cyclooxygenase (COX)-2, interleukin (IL)-6, collagen I, collagen III, matrix metallopeptidase 1 (MMP1), transforming growth factor β (TGFβ1), α smooth muscle actin (α-SMA), and hyaluronan synthase 1 (HAS1) were completed. Histological samples were completed for collagen and hyaluronic acid analysis.

RESULTS

RT-PCR results revealed that higher expressions of HAS1 and MMP1 and lower expressions of COX-2, IL-6, collagen I, collagen III, TGFβ1, and α-SMA were observed, and histological examination showed significantly increased hyaluronic acid, decreased deposition, and more organized configuration of collagen in injury with the cryotherapy cohort compared with the injury cohort.

CONCLUSIONS

Cryotherapy can inhibit the inflammatory reaction and simulate a fetal healing environment in extracellular matrix synthesis to regenerate vocal fold tissue with less fibrosis. Histological results showed that cryotherapy achieves a mature healing result with less scar, which tends to return to normal. In summary, the findings of this study suggest that administration of cryotherapy at the time of injury has the potential to minimize vocal fold scarring.

LEVEL OF EVIDENCE

NA Laryngoscope, 129:E151-E157, 2019.

Cryotherapy has antifibrotic and regenerative effects on human vocal fold fibroblasts

OBJECTIVES/HYPOTHESIS

Vocal fold scarring remains a major treatment challenge, and scar prevention without residual lesions remains a dilemma. Cryotherapy has shown cosmetic outcomes on skin lesions with minimal scarring. The aim of this study was to clarify the beneficial effects of cryotherapy for the prevention and the treatment of vocal fold scarring.

STUDY DESIGN

In vitro.

METHODS

Primary cultures of human vocal fold fibroblasts (VFFs) were used in this study. Myofibroblast differentiation was stimulated by transforming growth factor β1 (TGF-β1). We mimicked the cryotherapy effect on vocal fold healing in vivo by freezing VFFs ± TGF-β1 in vitro. The influence of freezing on cell viability, proliferation, migration, and contractile properties were analyzed. The expression of collagen I, collagen III, fibronectin, TGF-β1, matrix metallopeptidase 1 (MMP1), hyaluronan synthase 1 (HAS1) were investigated by real-time polymerase chain reaction (RT-PCR), and the expression of alpha smooth muscle actin (α-SMA) and decorin were investigated by RT-PCR and Western blot.

RESULTS

Freezing was found to modify extracellular matrix (ECM) synthesis and differentiation of VFFs. Expression of collagen I, collagen III, fibronectin, α-SMA, and TGF-β1 was downregulated, and MMP1 was upregulated in VFFs + TGF-β1 (myofibroblast) by freezing. HAS1 and decorin were upregulated in both VFFs ± TGF-β1 by freezing. Freezing VFFs + TGF-β1 (myofibroblast) with fast thawing had a lower expression of α-SMA when compared with slow thawing. Freezing reduced the migration and collagen contraction of VFFs + TGF-β1 (myofibroblast).

CONCLUSION

Cryotherapy induces antifibrotic and regenerative ECM alterations in VFFs. These data provide insight into the prevention and the treatment of vocal fold scarring with cryotherapy in phonomicrosurgery.

LEVEL OF EVIDENCE

NA Laryngoscope, 129:E143-E150, 2019.

Healing process following laser cordectomy of early glottis carcinoma from endoscopic view

BACKGROUND AND OBJECTIVE

Transoral laser surgery is useful for treating early glottic carcinoma. Wound areas after carbon dioxide (CO2 ) laser surgery are not covered by flaps, delaying healing. The healing process following laser cordectomy is not well understood. In this study, laryngoscopes were used to monitor the normal healing process after laser cordectomy and to determine if there was residual or recurrent disease.

MATERIALS AND METHODS

This prospective case study included 36 patients who underwent CO2 laser surgery for early glottis carcinoma between January 2011 and June 2014 at a university tertiary referral center. Postoperative complications, oncologic results, and mucosal stabilization time were analyzed. Vocal fold stabilization was defined as an absence of gross changes during two consecutive follow-up examinations.

RESULTS

The 3-year overall survival rate was 100% and the 3-year local control rate was 94%. Vocal cord stabilization was observed in 29 patients at a mean 88.1 days, with stabilization associated with the type of cordectomy (P < 0.05). During the wound-healing process, two patients experienced local recurrences. One had a persistent white patch for over 4 months and the other presented with a new mass in a non-operated area. Biopsies of both lesions showed recurrent disease. Postoperative complications included granulation in two patients and anterior commissure adhesion in one.

CONCLUSION

CO2 laser microsurgery is an effective treatment for early glottis carcinoma. Close attention should be paid to delays in healing process after laser surgery. Interventions should be considered for patients with abnormal laryngoscopic appearance or overly prolonged healing. Lasers Surg. Med. 48:483-489, 2016. © 2016 Wiley Periodicals, Inc.

Subfreezing versus room-temperature balloon dilation of benign tracheal stenosis: a pilot study in rabbits

We conducted an experiment to compare collagen deposition in tracheal stenoses dilated with room-temperature balloons and stenoses dilated with balloons at a subfreezing temperature (-10°C). Six New Zealand white rabbits underwent endoscopic tracheal injury. Tracheal dilation was performed at 3 weeks postinjury with either a room-temperature balloon or a vascular cryoplasty balloon. Five surviving rabbits were sacrificed at either 2 weeks (n = 3) or 4 weeks (n = 2) postdilation (1 rabbit that was not able to tolerate dilation was euthanized during the procedure). A blinded pathologist graded histologic sections of the injured tracheas for collagen content. The tracheal collagen deposits in the 3 animals sacrificed at 2 weeks postdilation were all graded as moderate. However, at the 4-week postdilation examination, there was a marked difference in collagen deposition between the rabbit that underwent room-temperature dilation and the rabbit that underwent subfreezing dilation; while the former showed moderate collagen deposition, the deposition in the latter was only mild. In conclusion, this pilot study showed that tracheal dilation with balloon cryotherapy decreased collagen deposition in the injured airway of 1 animal. Larger studies are required to determine whether balloon cryotherapy improves the long-term patency of immature tracheal stenosis.

Effects of cryotherapy on the maxillary antrostomy patency in a rabbit model of chronic rhinosinusitis

It is acknowledged that many causes of failures in endoscopic sinus surgery are related to scarring and narrowing of the maxillary antrostomy. We assessed the effect of low-pressure spray cryotherapy in preventing the maxillary antrostomy stenosis in a chronic rhinosinusitis (CRS) rabbit model. A controlled, randomized, double-blind study was conducted on 22 New Zealand rabbits. After inducing unilateral rhinogenic CRS, a maxillary antrostomy was performed and spray cryotherapy was employed on randomly selected 12 rabbits, while saline solution was applied to the control group (n = 10). The antrostomy dimensions and the histological scores were assessed 4 weeks postoperatively. The diameter of cryotreated antrostomy was significantly larger at 4 weeks than that in the control group. At 4 weeks, the maxillary antrostomy area in the study group was significantly larger than the mean area in the control group (103.92 ± 30.39 mm² versus 61.62 ± 28.35 mm², P = 0.002). Submucosal fibrous tissues and leukocytic infiltration in saline-treated ostia were more prominent than those in cryotreated ostia with no significant differences between the two groups regarding the histological scores. Intraoperative low-pressure spray cryotherapy increases the patency of the maxillary antrostomy at 4 weeks postoperatively with no important local side effects.

Subfreezing versus Room-Temperature Balloon Dilation of Benign Tracheal Stenosis: A Pilot Study in Rabbits

We conducted an experiment to compare collagen deposition in tracheal stenoses dilated with room-temperature balloons and stenoses dilated with balloons at a subfreezing temperature (-10°C). Six New Zealand white rabbits underwent endoscopic tracheal injury. Tracheal dilation was performed at 3 weeks postinjury with either a room-temperature balloon or a vascular cryoplasty balloon. Five surviving rabbits were sacrificed at either 2 weeks (n = 3) or 4 weeks (n = 2) postdilation (1 rabbit that was not able to tolerate dilation was euthanized during the procedure). A blinded pathologist graded histologic sections of the injured tracheas for collagen content. The tracheal collagen deposits in the 3 animals sacrificed at 2 weeks postdilation were all graded as moderate. However, at the 4-week postdilation examination, there was a marked difference in collagen deposition between the rabbit that underwent room-temperature dilation and the rabbit that underwent subfreezing dilation; while the former showed moderate collagen deposition, the deposition in the latter was only mild. In conclusion, this pilot study showed that tracheal dilation with balloon cryotherapy decreased collagen deposition in the injured airway of 1 animal. Larger studies are required to determine whether balloon cryotherapy improves the long-term patency of immature tracheal stenosis.

Cryoablation of persistent Barrett's epithelium after definitive chemoradiation therapy for esophageal adenocarcinoma

BACKGROUND

Dysplastic Barrett's epithelium (BE) persists after chemoradiation therapy for esophageal adenocarcinoma (EAC) arising in Barrett's esophagus. This phenomenon may present a significant risk for development of metachronous adenocarcinoma.

OBJECTIVE

To analyze the safety and efficacy of endoscopic cryoablation therapy for persistent dysplastic BE in patients with complete clinical response after definitive chemoradiation therapy for EAC.

DESIGN

Retrospective cohort study.

SETTING

Single National Cancer Institute Comprehensive Cancer Center experience.

PATIENTS

Radiation and endoscopic oncology treatment records were reviewed between January 2004 and September 2009. Fourteen patients with EAC who had been treated with definitive chemoradiation therapy followed by cryoablation were identified.

INTERVENTION

Cryoablation therapy.

MAIN OUTCOME MEASUREMENTS

Reduction in Prague Classification and dysplasia status following cryoablation therapy. Complications reported at 24 hour after the procedure telephone survey and at subsequent endoscopy.

RESULTS

After complete clinical response of EAC to chemoradiation therapy, the median length of persistent BE was Prague classification C1M4 (C = circumferential extent, M = maximal extent). Cryoablation reduced the median length of persistent BE to Prague classification C0M1 (P = .009 with respect to circumferential extent and P = .004 with respect to maximal extent of BE). All 14 patients had dysplastic BE. Cryoablation resulted in histological downgrading in all 14 patients. Among patients with high-grade dysplasia, 20% (2/10) were reduced to low-grade dysplasia, 60% (6/10) to BE with no dysplasia, and 20% (2/10) to no BE. Among patients with low-grade dysplasia, 75% (3/4) were reduced to BE with no dysplasia, and 25% (1/4) to no BE. The median number of cryoablation treatments administered to the 14 patients evaluated was 1 (mean 1.5, range 1-5). Eighty-six percent (12/14) of patients reported no complaints during the 24 hours after cryoablation. No occurrences of perforation and no esophageal strictures were reported at surveillance endoscopy.

LIMITATIONS

Single-center, retrospective design involving a small number of patients.

CONCLUSION

Our observations suggest that cryoablation therapy is safe and effective for the treatment of persistent BE after definitive chemoradiation.

Establishing a new animal model for the study of laryngeal biology and disease: an anatomic study of the mouse larynx

PURPOSE

Animal models have contributed greatly to the study of voice, permitting the examination of laryngeal biology and the testing of surgical, medical, and behavioral interventions. Various models have been used. However, until recently, the mouse (Mus musculus) has not been used in laryngeal research, and features of the mouse larynx have not been defined. Therefore, the purpose of this study was to qualitatively describe mouse laryngeal anatomy in relation to known human anatomy.

METHODS

Larynges of 7 C57BL mice were examined and photographed under stereotactic and light microscopy.

RESULTS

The authors found that mouse laryngeal organization was similar to that of humans. The hyoid bone and epiglottal, thyroid, cricoid, and arytenoid cartilages were identified. An additional cartilage was present ventrally. Thyroarytenoid, posterior cricoarytenoid, lateral cricoarytenoid, and cricothyroid muscles were grossly positioned as in humans. Interarytenoid muscles were not present; however, a functional counterpart was identified.

CONCLUSIONS

The authors provide an initial description of mouse laryngeal anatomy. Because of its amenability to genetic engineering, the mouse is the premiere model for the study of disease and the testing of interventions. Introduction of the mouse model for laryngeal study offers a tool for the study of normal laryngeal cell biology and tissue response to disease processes.

Intralesional cryosurgery for the treatment of hypertrophic scars and keloids following aesthetic surgery: the results of a prospective observational study

Hypertrophic scars and keloids following aesthetic surgery, which ignite patient dissatisfaction, are difficult to handle. Intralesional cryosurgery for the treatment of such scars has been introduced. This study was designed to evaluate the efficacy of this technology in the treatment of such scars and to assess the reduction of dissatisfaction. Eleven scars (on 11 patients) were treated by intralesional cryosurgery, following breast surgery, otoplasty, face-lifting, and brachioplasty. Each patient scored the concern from the scar and the scar deformity (scale from 1 to 5) prior and following treatment (higher score represents least satisfaction and a severe deformity). The follow-up period was between 3 months and 8 years. The results demonstrated a significant reduction in concern and deformity scores compared with before the cryotreatment (P = .001). The intralesional cryosurgery technique provides the plastic surgeon with an effective instrument to treat hypertrophic scars and keloids following aesthetic surgery, thus reducing the dissatisfaction of patients.