Laryngeal transplantation: research, clinical experience, and future goals

Voice Rehabilitation After Laryngeal Transplantation: Own Experience

BACKGROUND AND PURPOSE

Laryngeal transplantation (LT) remains an infrequently performed procedure due to well-defined and limited medical indications. The challenges include a very complicated surgery, continuous immunosuppressive treatment, as well as post-transplant rehabilitation of voice, speech, and swallowing. The aim of this paper is to describe a model of voice and speech rehabilitation after LT, based on our own experience.

STUDY DESIGN

Observational study.

METHOD

Presented here are the rehabilitation processes of two patients who had previously undergone LT as well as their pre- and postrehabilitation voice outcomes. Both patients underwent voice, speech, and swallowing rehabilitation in the fifth month after LT.

RESULTS

One of the patients had a significant improvement in voice quality. While, the other did not regain his natural, sonorous voice, but he scored very high on a voice self-assessment test.

CONCLUSION

Voice rehabilitation after LT is a complex and long-term process that requires the involvement of a team of specialists. The optimal anatomical conditions restored during surgery, the patient's motivation and the support of professionals make it possible to return to normal verbal communication.

Laryngeal graft after total laryngectomy in humans: A SWiM analysis

Evaluation of the results of laryngeal transplantation (LT) in humans. Analysis of 3 bibliographic databases with the keywords "larynx, transplantation, autograft". In total, 626 abstracts were read and 25 articles selected. The main objective was to analyze the characteristics of laryngeal transplant patients. The accessory objectives comprised analysis of operative technique, immunosuppressive treatment and results. Four articles were selected for analysis. Two patients were transplanted after total laryngectomy for laryngeal carcinoma and 2 after laryngeal trauma. Three of the 4 patients had true transplantation with arterial, venous and neural microanastomosis. Two patients were decannulated and the tracheostomy tube was maintained in the other 2. Three of the 4 patients had good-quality phonation and could feed without a gastric tube. One patient died of carcinoma progression and 1 patient had to be explanted 14 years after transplantation. The number of LTs reported is too small for scientific determination of the place of this intervention in laryngology. The published results could, at first sight, suggest that the future of LT is uncertain. However, several elements, also suggest that otolaryngologists should continue to take an interest in this technique.

Laryngeal Applications of Platelet Rich Plasma and Platelet Poor Plasma: A Systematic Review

BACKGROUND

Platelet rich plasma (PRP) and platelet poor plasma (PPP) are regenerative therapies that offer the potential for improving care for disorders of the larynx. The laryngeal applications of these substances have been examined in both animals and humans. The goal of this systematic review is to examine the various applications of PRP and PPP in laryngology, assess the protocols for preparation and application of these substances and evaluate the outcomes and complications in both humans and animals.

METHODS

A search of PUBMED was conducted in April 2021 using combinations of keywords of "platelet rich plasma" and "platelet poor plasma" with keywords such as "larynx," "vocal folds," "laryngology," and others. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRIMSA) guidelines were followed. Articles were reviewed by two independent coauthors and included based on selection criteria pertinent to the goals of this study. The risk of bias in the included studies was assessed by two independent co-authors using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist for Randomized Controlled Trials and JBI Critical Appraisal Checklist for Quasi-Experimental Studies. Data regarding the pathologies treated using PRP and PPP, PRP, and PPP preparation protocols, application protocols, human voice outcomes, histopathological animal outcomes, and complications were extracted from each of the studies and presented in tables.

RESULTS

Seven studies were included based on the selection criteria. PRP or PPP were used for vocal fold scar, sulcus, atrophy and palsy; acute vocal fold injury; glottic insufficiency, and graft healing. PRP or PPP were derived from autologous blood in a one- or two-step centrifugation process and administered via injection, soaking of cartilage grafts or topical application. Mean and median voice handicap index-10 (VHI-10) and voice handicap index (VHI) scores decreased following PRP or PPP injections in two human studies and one human study showed a similar VHI-10 score before and after PRP treatment. Videostroboscopy showed the absence of injection site reactions and at least temporary improvement in glottic gap or vibratory function following treatment in some patients. Other objective measures of voice outcomes in human studies showed improved phonatory function in the one-to-four-month period following PRP or PPP injections, with some patients experiencing a subjective decrease or return to baseline in phonatory function following the initial improvement period. Animal studies found elevated levels of growth factors, organized collagen deposition, decreased granulation tissue, increased vascularization, and increased cartilage proliferation in PRP treated laryngeal tissue.

DISCUSSION

PRP and PPP might have the potential to be safely used in the larynx and at least temporarily influence wound healing and vocal function. Further study using comparable outcome measurement tools is required to assess their role and efficacy in treating acute vocal fold injury, chronic vocal fold pathologies, graft healing, and other laryngeal applications.

Efficacy of platelet-rich plasma (PRP) in benign vocal fold lesions: a systematic review and meta-analysis

OBJECTIVES

To evaluate the efficacy of platelet-rich plasma (PRP) in benign vocal fold lesions.

METHODS

MEDLINE, Cochrane Central, Web of Science, and Scopus databases were searched in April 2023 for relevant clinical trials. Inclusion criteria were clinical trials evaluating the efficacy of PRP in benign vocal fold lesions. We conducted a comparative double-arm analysis using the pooled mean difference (MD) and 95% confidence interval (CI). Outcomes of interest included the vocal handicap index (VHI), the Jitter and Shimmer percentages, and the noise-to-harmonic ratio (NHR).

RESULTS

Six studies matched the inclusion criteria. The pooled analysis shows that PRP was associated with significantly lower VHI scores compared with the control (MD = - 5.06, p < 0.01). Regarding the Jitter percentage, the PRP group was not superior to the control group at 2 and 4 weeks. However, the results revealed that PRP significantly reduced the Jitter percentage at 3 months (MD = - 0.61, p = 0.0008). The overall analysis favored the PRP arm significantly (p < 0.001). As for the Shimmer percentage, the combined effect estimate favored the PRP group (MD = - 1.22, p = 0.002). Subgroup analysis according to the time did not reveal any significant differences between studies at 2 weeks, 4 weeks, and 3 months. The analysis of the NHR outcome revealed a significant difference between both groups (MD = -1.09, p = 0.01). However, at 4 weeks, the treatment group had a significantly lower NHR % compared to the control group (MD = - 0.61, p = 0.02). There was no significant difference at 3 months (MD = - 2.14, p = 0.14).

CONCLUSIONS

Platelet-rich plasma is effective in reducing VHI scores, Jitter and Shimmer percentages, and NHR values. This effect is more evident after follow-up, especially 3 months.

Safety of Platelet-Rich Plasma Subepithelial Infusion for Vocal Fold Scar, Sulcus, and Atrophy

OBJECTIVE

To demonstrate the safety profile of platelet-rich plasma (PRP) as an injectable therapeutic for the treatment of vocal fold scarring and atrophy.

METHODS

Preliminary report on a prospective clinical trial of patients with vocal fold scar or atrophy undergoing unilateral vocal fold subepithelial infusion with autologous PRP. Enrolled patients underwent four subepithelial injections spaced 1 month apart. Adverse events were assessed peri and post-injection at each session. Patient-reported outcomes were collected at every visit using the Voice Handicap Index-10 (VHI-10) and Vocal Fatigue Index (VFI) questionnaires.

RESULTS

Twelve patients underwent unilateral vocal fold injection with autologous PRP prepared according to Eclipse PRP® system protocol. Forty-three injections were performed using a peroral or percutaneous approach. An average of 1.57 ± 0.4 cc (range 0.6-2.0 cc) injectate was used. All patients tolerated the procedure without difficulty or peri-procedural complications. The average duration of follow-up was 3.6 ± 1.8 months. No significant inflammatory reactions or adverse events were seen to date. There was statistically significant improvement in patient-reported outcomes at the 3 month follow up (n = 9) follow-up (mean ΔVHI-10 = 10.8, p < 0.001, mean ΔVFI = 18.9, p = 0.01, t test, paired two sample for means, two-tail). All nine patients who completed the series of four injections subjectively (yes/no) reported they were satisfied with the results.

CONCLUSION

This prospective study cohort demonstrated a favorable safety profile, with no adverse events or peri-procedural complications. Subjective improvements in vocal quality and reduction in vocal fatigue need to be clinically correlated with further study.

LEVEL OF EVIDENCE

4 Laryngoscope, 133:647-653, 2023.

The current status of human laryngeal transplantation in 2017: A state of the field review

OBJECTIVES

Human laryngeal allotransplantation has long been contemplated as a surgical option following laryngectomy, but there is a paucity of information regarding the indications, surgical procedure, and patient outcomes. Our objectives were to identify all human laryngeal allotransplants that have been undertaken and reported in the English literature and to evaluate the success of the procedure.

DATA SOURCES

MEDLINE, Embase, Current Index to Nursing and Allied Health Literature, Web of Science and Scopus, and the Gray literature.

REVIEW METHODS

A comprehensive search strategy was undertaken across multiple databases. Inclusion criteria were case reports of patients who had undergone human laryngeal allotransplantation. Information regarding indications, operative techniques, complications, graft viability, and functional outcomes were extracted.

RESULTS

A total of 5,961 articles, following removal of duplicates, matched the search criteria and were screened, with five case reports relating to two patients, ultimately fulfilling the entry criteria.

CONCLUSIONS

Two laryngeal transplants have been reported in the medical literature. Although both patients report improved quality of life relating to their ability to communicate with voice, further research is necessary to shape our understanding of this complicated operation, its indications, and its functional outcomes. Laryngoscope, 127:1861-1868, 2017.

Laryngeal Transplantation

Patients who require laryngectomy usually do not want to completely or partially lose their larynx. Laryngeal transplantation (LT) is a composite tissue transplantation from a cadaver to an alive recipient and requires lifelong immunosuppression in postoperative term. The aims of LT are breathing without tracheostoma, normal swallowing, and voice production. To date, only two successful complete LT have been performed in human despite many researches. The requirement of post-transplant immunosuppressive treatment has ethical concern for the larynx, which is a non-vital organ. However, LT may be an option for improving the quality of life of patients undergoing laryngectomy. In this study, we discussed the LT procedure and researches with the literature.

Risk acceptance and expectations of laryngeal allotransplantation

BACKGROUND

Laryngeal allotransplantation (LA) is a technique involving transplantation of a deceased donor's larynx into a recipient, and it may be substituted for conventional laryngeal reconstruction. There are widely different views on LA, as the recipient is administered continuous, potentially life-threatening, immunosuppressive therapy for a functional or aesthetic result, which is not directly related to life extension. The purpose of this study was to analyze the difference in risk acceptance and expectations of LA between four population groups.

METHODS

A survey was performed to examine patients' risk acceptance and expectations of LA. The survey included 287 subjects in total (general public, n=100; kidney transplant recipients, n=53; post-laryngectomy patients, n=34; doctors, n=100), using a Korean translated version of the louisville instrument for transplantation (LIFT) questionnaire.

RESULTS

All four groups responded differently at various levels of their perception in risk acceptance and expectations. The kidney transplant recipients reported the highest risk acceptance and expectations, and the doctor group the lowest.

CONCLUSIONS

This study examined the disparate perception between specific population groups of the risks and benefits of using LA for the promotion of the quality of life. By addressing the information gaps about LA in the different populations that have been highlighted from this survey, we suggest that LA can become a more viable alternative to classical surgery with resultant improved quality of life for patients.

Impact of donor-specific antibodies in reconstructive transplantation

For many devastating injuries and tissue defects where conventional reconstruction is not possible, reconstructive transplantation such as hand and face transplantation has become a viable alternative. This novel approach allows for improved restoration of appearance, anatomy and function not feasible by other available treatment options. However, clinical management of these injuries prior to transplantation frequently requires multiple blood transfusion or skin grafts resulting in the formation of alloantibodies (anti-HLA IgG Abs) and a high degree of sensitization. The role of donor-specific antibodies (DSA) and mechanisms of antibody-mediated rejection (AMR) in reconstructive transplantation are still largely unknown. Thus there is an imminent need to develop a better understanding of the mechanisms related to DSA and AMR after reconstructive transplantation. In this review, we will define the role of DSA and mechanisms of AMR in reconstructive transplantation and compare them to established measures and treatment concepts in solid organ transplantation.

Laryngeal allotransplantation by stages in beagles: an initial study

OBJECTIVE

To establish a model of cynolaryngeal transplantation.

METHODS

Ten beagles, matched for weight (8-10 kg) were divided into five groups for allotransplantation. The vascular circulation was managed with an end-to-end or end-to-lateral anastomosis of allograft bilateral common carotid arteries to recipient bilateral common carotid arteries, and bilateral external jugular veins. The recurrent laryngeal nerve was anastomosed end-to-end. Then, a vascularized allograft was embeded in the cervical subcutaneous tissue of the recipient, and cyclosporine administered every day.

RESULTS

The allografts in groups 3, 4, and 5 survived up to 1 month. Groups 1 and 2 showed necrosis and cervical infection.

CONCLUSIONS

Beagles accepted laryngeal allotransplantation by stages (laryngeal allograft fore-embed model). Allograft survival was secluded by glandular organ secretion. Immunosuppression must be continuously administered.