End-to-end anastomosis in the management of laryngotracheal defects

Sleeve resection with end-to-end anastomosis in the reconstruction of tracheal defects exceeding six rings: a clinical feasibility study and safety assessment

Objectives

Reconstruction is always required for tracheal defects and sleeve resection with end-to-end anastomosis is the most common used. The aim of the study was to present surgical techniques and evaluate the outcomes of sleeve resection with end-to-end anastomosis in the reconstruction of tracheal defects exceeding six rings.

Methods

The study included patients with primary or secondary malignancies and tracheal stenosis from 2014 to 2019, who were treated with sleeve resection exceeding six tracheal rings, and reconstructed with end-to-end anastomosis. Airway status and patient outcomes were the principal follow-up measures.

Results

A total of 16 patients were enrolled in the study including three primary tracheal malignancies, 12 invasive thyroid carcinomas and one with tracheal stenosis. The extent of tracheal resection ranged from seven to nine rings, and the primary end-to-end anastomosis was performed in all 16 patients. Performance of tracheostomy or cricothyroidotomy was done in 6 patients with decannulation at a median of 42 days (range, 28-56). No anastomotic dehiscence, infection or bleeding occurred postoperatively, and all 16 patients maintained an unobstructed airway through the end of follow-up.

Conclusions

Sleeve resection reconstructed with end-to-end anastomosis can serve as an appropriate therapeutic strategy for the tracheal defects even exceeding six rings. Adequate laryngeal release is the key to surgical success.

A Neglected Open Laryngeal Wound: A Rare Presentation of Neck Trauma

Laryngotracheal trauma can be potentially lethal. Improper healing can have long term sequelae such as permanent voice change, laryngotracheal stenosis and impaired swallowing severely affecting an individual's quality of life. Thus early identification and prompt treatment is paramount to achieve good outcomes in laryngotracheal trauma. A 45 year old male presented with an open laryngeal wound 12 days after sustaining the injury. Surgical closure of the wound was done. A suprahyoid drop was done to achieve tension free repair of the laryngeal rent. Chin to chest sutures were used to maintain neck flexion in the post-operative period. We were able to achieve a good surgical outcome with regards to the patients voice, airway and swallowing in spite of the delayed presentation.

A novel classification of tracheal defects and the reconstruction strategies: A retrospective study based on 106 cases

Objective

The study aims to present a novel classification of tracheal defects and the corresponding reconstruction strategies.

Methods

The retrospective study was designed to analyze patients with diagnosed primary or secondary tracheal tumors from 1991 to 2020. Surgical techniques, complications and prognosis were reviewed. Airway status and patient outcomes were the principal follow-up measures. Tracheal defects were classified into two plane sizes (vertical (V) and horizontal (H) planes). Vertical defects were further categorized into three groups based on their tracheal ring numbers (V1, ≤ 5 rings; V2, 6-10 rings; and V3, > 10 rings). Tracheal defects with horizontal plane size H1 and H2 represent defects less and more than one-half the circumference of trachea. Thus, suitable reconstruction strategies were planned primarily based on "V" and "H" classifications. The reconstruction strategies performed were sleeve resection followed by an end-to-end anastomosis, window resection with sternocleidomastoid myoperiosteal flap reconstruction, defects conversion with rotation anastomosis, and modified tracheostomy with secondary flap reconstruction.

Results

A total of 106 patients diagnosed with tracheal defects were enrolled in the study, of whom 59 patients underwent sleeve resection followed by end-to-end anastomosis; 40 patients received window resection alongside sternocleidomastoid (SCM) myoperiosteal flap reconstruction; five patients received converting defects with rotation anastomosis and two patients underwent modified tracheostomy with secondary stage flap reconstruction. Lumen stenosis occurred in three V2H1 defect cases and were treated by a second reconstruction surgery. Iatrogenic unilateral recurrent laryngeal nerve paralysis occurred in two patients with the V3H2 defect type, who were treated by temporary tracheotomy and partial vocal cord resection and extubated successfully during follow-up. All 106 patients achieved airway patency with adequate laryngeal function at the end of follow-up. No anastomotic dehiscence or bleeding occurred in any patient postoperatively.

Conclusion

Though a significant number of multicenter studies concerning the reconstruction and classification of tracheal defects are needed, the study herein provides a novel classification of tracheal defects, which is primarily developed on the defect size. Therefore, the study might serve as a potential source for identifying suitable reconstruction strategies for practitioners.

Standardization of Microcomputed Tomography for Tracheal Tissue Engineering Analysis

Tracheal tissue engineering has become an active area of interest among clinical and scientific communities; however, methods to evaluate success of in vivo tissue-engineered solutions remain primarily qualitative. These evaluation methods have generally relied on the use of photographs to qualitatively demonstrate tracheal patency, endoscopy to image healing over time, and histology to determine the quality of the regenerated extracellular matrix. Although those generally qualitative methods are valuable, they alone may be insufficient. Therefore, to quantitatively assess tracheal regeneration, we recommend the inclusion of microcomputed tomography (μCT) to quantify tracheal patency as a standard outcome analysis. To establish a standard of practice for quantitative μCT assessment for tracheal tissue engineering, we recommend selecting a constant length to quantify airway volume. Dividing airway volumes by a constant length provides an average cross-sectional area for comparing groups. We caution against selecting a length that is unjustifiably large, which may result in artificially inflating the average cross-sectional area and thereby diminishing the ability to detect actual differences between a test group and a healthy control. Therefore, we recommend selecting a length for μCT assessment that corresponds to the length of the defect region. We further recommend quantifying the minimum cross-sectional area, which does not depend on the length, but has functional implications for breathing. We present empirical data to elucidate the rationale for these recommendations. These empirical data may at first glance appear as expected and unsurprising. However, these standard methods for performing μCT and presentation of results do not yet exist in the literature, and are necessary to improve reporting within the field. Quantitative analyses will better enable comparisons between future publications within the tracheal tissue engineering community and empower a more rigorous assessment of results. Impact statement The current study argues for the standardization of microcomputed tomography (μCT) as a quantitative method for evaluating tracheal tissue-engineered solutions in vivo or ex vivo. The field of tracheal tissue engineering has generally relied on the use of qualitative methods for determining tracheal patency. A standardized quantitative evaluation method currently does not exist. The standardization of μCT for evaluation of in vivo studies would enable a more robust characterization and allow comparisons between groups within the field. The impact of standardized methods within the tracheal tissue engineering field as presented in the current study would greatly improve the quality of published work.

From the clavicle to the windpipe: Tracheal window resections reconstructed with calcifying periosteum in thyroid cancer

OBJECTIVES

We aimed to evaluate the outcomes of tracheal window resection and reconstruction using a vascularized periosteal flap (intended for calcification) harvested from the medial clavicle. This is one of several surgical techniques for tracheal resection and reconstruction used for patients with thyroid carcinoma invading the trachea. Importantly, in partial tracheal resection postoperative dynamic airway collapse must be prevented. Reconstruction of the tracheal defect with a vascularized periosteal flap is one method of achieving a stable airway.

METHODS

Twelve patients with locally advanced thyroid carcinoma who underwent tracheal resection and reconstruction at Oslo University Hospital from 2004 to 2017 were studied retrospectively. The primary outcome was a stable airway not requiring airway stenting. The secondary outcomes were the time to decannulation, morbidity, and survival.

RESULTS

Eleven of 12 patients did not require airway stenting postoperatively after a median of 111 days. Seven patients developed postoperative complications. The median observation time was 74.8 months (range 10.5-153.5) for all patients. The median disease-free survival was 40 months (range 0-147). By February 1, 2020, seven patients were alive, of whom five showed no evidence of disease.

CONCLUSIONS

Tracheal reconstruction with a vascularized periosteal flap yielded good results in terms of establishing a stable airway. This procedure is a viable reconstructive option that allows for decannulation by preventing airway collapse, thereby potentially mitigating the need for end-to-end (ETE) anastomosis or sleeve resections. For selected patients, this procedure may prevent local fatal complications from thyroid cancer invading the trachea.

LEVEL OF EVIDENCE

Level 4.

Tracheal Resection in the Management of Thyroid Cancer: An Evidence-Based Approach

OBJECTIVE

Determine the effect of patient demographics and surgical approach on patient outcomes after tracheal resection in the management of thyroid cancer.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

Systematic review of literature was performed using PubMed, Embase, and Cochrane Library to identify patients with thyroid carcinoma who underwent tracheal resection. Pooled estimates for patient demographics, presenting findings, complications, and outcomes are determined using random-effects meta-analyses.

RESULTS

Ninety-six relevant studies encompassing 1,179 patients met inclusion criteria. Meta-analysis pooled rates of complications: 1.7% (confidence interval [CI] 0.8-2.5; P < .001; I² = 1.85%) airway complications, 2.8% (CI 1.6-3.9; P < .001; I² = 13.34%) bilateral recurrent laryngeal nerve paralysis, 2.2% (CI 1.2-3.1; P < .001; I² = 6.72%) anastomotic dehiscence. Circumferential resection pooled estimates major complications, locoregional recurrence, distal recurrence, overall survival: 14.1% (CI 8.3-19.9; P < .001; I² = 35.26%), 15% (CI 9.6-20.3; P < .001; I² = 38.2%), 19.7% (CI 13.7-25.8; P < .001; I² = 28.83%), 74.5% (CI 64.4-84.6; P < .001; I² = 85.07%). Window resection estimates: 19.8% (CI 6.9-32.8; P < .001; I² = 18.83%) major complications, 25.6% (CI 5.1-46.1; P < .014; I² = 84.68%) locoregional recurrence, 15.6% (CI 9.7-21.5; P < .001; I² = 0%) distal recurrence, 77.1% (CI 58-96.2; P < .001; I² = 78.77%) overall survival.

CONCLUSION

Management of invasive thyroid carcinoma may require tracheal resection to achieve locoregional control. Nevertheless, postoperative complications are not insignificant, and therefore this risk cannot be overlooked when counseling patients perioperatively. Laryngoscope, 131:932-946, 2021.

M2 Macrophages Promote Collagen Expression and Synthesis in Laryngotracheal Stenosis Fibroblasts

OBJECTIVE

Macrophages exhibit distinct phenotypes and are dysregulated in a model of iatrogenic laryngotracheal stenosis (iLTS). Increased populations of alternatively activated or M2 macrophages have been demonstrated. However, the role of these macrophages is unknown. The aims of this study are: 1) define the macrophage population in iLTS in the context of classically activated or M1 and M2 macrophage phenotypes, and 2) characterize the effect of monocyte-derived M1 and M2 macrophages on normal airway and LTS-derived fibroblasts (FBs) in vitro.

STUDY DESIGN

Comparative analysis; in vitro controlled study.

METHODS

Immunohistochemical analysis of human iLTS and control specimens was performed to define the macrophage population. In vitro, M1, and M2 macrophages were polarized using M-CSF + Interferon-gamma and lipopolysaccharide or Interleukin-4, respectively. FBs isolated from laryngotracheal scar (LTS-FBs) and normal tracheal airway (NA-FBs) in eight patients with iLTS were cocultured with polarized macrophages. Fibrosis gene expression, soluble collagen production, and proliferation were assessed.

RESULTS

Immunohistochemical analysis revealed increased CD11b + cells (macrophage marker) in laryngotracheal scar specimens (18.3% vs. 8.5%, P = .03) and predominant CD206 (M2) costaining versus CD86 (M1) (51.5% vs. 9.8%, n = 10, P = .001). In vitro, NA-FBs cultured with M2 macrophages demonstrated a 2.41-fold increase in collagen-1 expression (P = .05, n = 8) and an increase in soluble collagen (9.98 vs. 8.875, mean difference: 1.11 95%, confidence interval 0.024-2.192, n = 8, P = .015).

CONCLUSION

Increased populations of CD11b cells are present in iLTS specimens and are predominantly CD206+, indicating an M2 phenotype. In vitro, M2 macrophages promoted collagen expression in airway FBs. Targeting macrophages may represent a therapeutic strategy for attenuating fibrosis in iLTS.

LEVEL OF EVIDENCE

NA Laryngoscope, 131:E346-E353, 2021.

Biodegradable electrospun patch containing cell adhesion or antimicrobial compounds for trachea repair in vivo

Difficulty breathing due to tracheal stenosis (i.e. narrowed airway) diminishes the quality of life and can potentially be life-threatening. Tracheal stenosis can be caused by congenital anomalies, external trauma, infection, intubation-related injury, and tumors. Common treatment methods for tracheal stenosis requiring surgical intervention include end-to-end anastomosis, slide tracheoplasty and/or laryngotracheal reconstruction. Although the current methods have demonstrated promise for treatment of tracheal stenosis, a clear need exists for the development of new biomaterials that can hold the trachea open after the stenosed region has been surgically opened, and that can support healing without the need to harvest autologous tissue from the patient. The current study therefore evaluated the use of electrospun nanofiber scaffolds encapsulating 3D-printed PCL rings to patch induced defects in rabbit tracheas. The nanofibers were a blend of polycaprolactone (PCL) and polylactide-co-caprolactone (PLCL), and encapsulated either the cell adhesion peptide, RGD, or antimicrobial compound, ceragenin-131 (CSA). Blank PCL/PLCL and PCL were employed as control groups. Electrospun patches were evaluated in a rabbit tracheal defect model for 12 weeks, which demonstrated re-epithelialization of the luminal side of the defect. No significant difference in lumen volume was observed for the PCL/PLCL patches compared to the uninjured positive control. Only the RGD group did not lead to a significant decrease in the minimum cross-sectional area compared to the uninjured positive control. CSA reduced bacteria growth in vitro, but did not add clear value in vivo. Adequate tissue in-growth into the patches and minimal tissue overgrowth was observed inside the patch material. Areas of future investigation include tuning the material degradation time to balance cell adhesion and structural integrity.

Secondary tracheal tumors: a systematic review

BACKGROUND

Secondary tracheal tumors arise from mural invasion by primary tumors in adjacent organs, metastatic lymph nodes or blood-born metastasis from distant sites. This systematic review aims to assess the presentation, management options, and clinical outcomes of these uncommon non-tracheal malignancies.

METHODS

Electronic searches of the MEDLINE database were performed to identify case series and individual case reports of tracheal invasion by primary non-tracheal tumors or metastatic disease. All English-language studies with available abstracts or articles containing primary data were included.

RESULTS

From 1978 to 2017, a total of 160 case reports or case series identified 2,242 patients with invasion of the trachea by tumors of adjacent organs (n=1,853) or by metastatic lymph nodes or hematogenous spread (n=389). Common primary sites of origin were thyroid, esophagus, and lung, and the most common presentation was metachronous (range of interval: 0 to 564 months) with dyspnea, neck mass, voice change and/or hemoptysis. A majority of patients in case reports (77.9%) and case series (66.0%) underwent resection and the most common reported operation was segmental tracheal resection. Fewer patients underwent bronchoscopic intervention (21.7%) and radiation was used in 32.2% of patients. Complications after bronchoscopic treatment included bleeding, granulation tissue, and retained secretions, while anastomotic leak, unplanned tracheostomy, and new recurrent laryngeal nerve paralysis were observed after surgical resection. The rate of 30-day mortality was low (0.01-1.80%). Median survival was higher in patients with thyroid malignancy and in patients who underwent surgical management. Follow-up time ranged from 0.03 to 183 months.

CONCLUSIONS

Patients with tracheal invasion by metastatic or primary non-tracheal malignancies should be assessed for symptoms, tumor grade, tumor recurrence and concurrent metastases to decide on optimal surgical, bronchoscopic or noninterventional therapy. Clinical experience suggests that palliative endoscopic intervention for tracheal obstruction by metastasis-bearing lymph nodes is underreported.