Management of Severe and Complex Hypopharyngeal and/or Laryngotracheal Stenoses by Various Open Surgical Procedures: A Retrospective Study of Seventeen Patients.

OBJECTIVE: To systematically study various surgical approaches for treating complex hypopharyngeal and/or laryngotracheal stenoses at a variety of sites and levels. PATIENTS AND METHODS: We retrospectively analyzed the treatment of 17 patients with severe and complex hypopharyngeal and/or laryngotracheal stenosis at various sites and levels of severity. All of the 17 patients initially had a tracheostomy. Thirteen had failed the previous laser lysis and/or dilation treatment. Given the high severity and complexity of stenosis, all of these patients were treated by open surgical reconstruction techniques using repairing grafts (flaps), followed by stenting. RESULTS: Thirteen of 17 patients had successful decannulation 1-8 months post-operation and had stable airway and adequate vocal and swallow function. Two patients with complex hypopharyngeal and esophageal stenosis had unsuccessful decannulation. Follow-up was lost in 1 patient with complex hypopharyngeal and esophageal stenosis and 1 patient with original hypopharyngeal stenosis and recurrent thoracotracheal stenosis. CONCLUSION: Despite the failure by the regular treatments using laser lysis and/or dilation therapy, severe and complex hypopharyngeal and/or laryngotracheal stenosis may be successfully treated by variable open surgical reconstruction techniques using different grafts (flaps) depending on the site and severity of the stenosis.

Reconstruction of tracheal wall defect with a mesh patch of nickel-titanium shape-memory alloy.

OBJECTIVES: We explored the feasibility of reconstructing tracheal wall defects with a mesh patch fashioned from a nickel-titanium shape-memory alloy. METHODS: A tracheal wall defect was first constructed surgically by resecting the anterior half of the tracheal wall between the second and sixth tracheal rings. The defect was reconstructed in 8 experimental animals by replacing the resected tracheal mucosa and tracheal cartilage with a pedicle skin flap, which was then enclosed in the mesh patch. In 4 control animals, only a pedicle skin flap with strap muscles was used in the reconstruction procedure. The performance of the animals was observed after surgery. At the end of the experiments, the reconstructed segment was harvested for anatomic evaluation. RESULTS: In the experimental group, 1 animal died 5 days after the operation. Endoscopic and anatomic examination of the 7 animals that survived the observation period showed that the reconstructed trachea was stable, with sufficient airway space for breathing. All 4 control animals died after the operation. After observing successful completion of this operation in animals, we successfully used this method to repair a tracheal wall defect in a human victim of a traffic accident. CONCLUSIONS: Tracheal defects can be successfully reconstructed by use of a mesh patch of nickel-titanium shape-memory alloy as an extraluminal stent--a method that avoids complications associated with intraluminal stents.

Long-term results of the sternohyoid myocutaneous rotary door flap for laryngotracheal reconstruction.

In the past 8 years, 45 patients with laryngotracheal stenosis have undergone reconstruction with the sternohyoid myocutaneous rotary door flap (RDF) technique at Tang Du Teaching Hospital in Xi'an, China. All patients were tracheostomy-dependent before reconstruction. Thirty-six patients had previously undergone 2 to 7 surgical procedures. Forty-one of the 45 patients (91%) were successfully decannulated. Decannulation failed in the other 4 because of RDF prolapse into the tracheal lumen or because of hypertrophic scar in the operative region. The follow-up period ranged from 1 to 8 years. Forty of the 41 patients had a stable airway and effective voice, and 1 patient had restenosis 3 years after decannulation. The results demonstrate that the RDF technique is a relatively simple and effective way to treat patients with laryngotracheal stenosis.

Both central and peripheral auditory systems are involved in salicylate-induced tinnitus in rats: a behavioral study.

OBJECTIVE: This study was designed to establish a low dose salicylate-induced tinnitus rat model and to investigate whether central or peripheral auditory system is involved in tinnitus. METHODS: Lick suppression ratio (R), lick count and lick latency of conditioned rats in salicylate group (120 mg/kg, intraperitoneally) and saline group were first compared. Bilateral auditory nerves were ablated in unconditioned rats and lick count and lick latency were compared before and after ablation. The ablation was then performed in conditioned rats and lick count and lick latency were compared between salicylate group and saline group and between ablated and unablated salicylate groups. RESULTS: Both the R value and the lick count in salicylate group were significantly higher than those in saline group and lick latency in salicylate group was significantly shorter than that in saline group. No significant changes were observed in lick count and lick latency before and after ablation. After ablation, lick count and lick latency in salicylate group were significantly higher and shorter respectively than those in saline group, but they were significantly lower and longer respectively than those in unablated salicylate group. CONCLUSION: A low dose of salicylate (120 mg/kg) can induce tinnitus in rats and both central and peripheral auditory systems participate in the generation of salicylate-induced tinnitus.

Structural integrity, ECM components and immunogenicity of decellularized laryngeal scaffold with preserved cartilage.

Decellularization techniques have been widely used as an alternative strategy for organ reconstruction. However, the compliance of tracheal or laryngeal tissues can be increased during the decellularization process, which might cause postoperative stenosis due to elimination of chondrocytes. The purpose of our study was to construct a decellularized, whole, laryngeal scaffold with preserved chondrocytes using perfusion techniques and to evaluate the immunogenicity of the decellularized scaffold in vitro and in vivo in a rat model. The cellular components and immunogenicity of the scaffold were decellularized after 14 h of perfusion with detergent and 48 h of perfusion with phosphate buffered saline. However, the cartilage was well preserved via histological analysis and a chondrocyte viability test. Compared to the fresh larynx, the decellularized larynx did not show the presence of major histocompatibility complex antigens via immunohistochemical analysis in vitro and no significant immune rejection occurred 12 weeks post-implantation. In conclusion, decellularization via perfusion can achieve a decellularized, whole-laryngeal scaffold with the cell components removed and the cartilage and extra-cellular matrix well preserved. T cell-mediated immune rejection was significantly reduced in decellularized laryngeal cartilaginous scaffolds in vivo.

[Observation of the efficacy of endoscopic myringoplasty with homoplastic amniotic membrane].

OBJECTIVE: To explore the clinical effectiveness of endoscopic myringoplasty with homoplastic amniotic membrane. METHOD: A retrospective study in 43 patients underwent endoscopic myringoplasty with homoplastic amniotic membrane was observed at the wound healing of tympanic membrane perforation and the hearing improve-threshold audiometry in 43 patients after surgery. RESULT: The tympanic membrane's perforation healing rate was 95.3% (41/43), and air conduction threshold audiometry in language frequency improved average 10 dB. The follow up was 1--4 years, and no recurrence or complications had occurred. CONCLUSION: The endoscopic myringoplasty could be able to simple myringoplasty whose air conduction threshold audiometry in language frequency was less than 40 dB. It could be used to repair not only the central perforation in tympanic membrane, but also the marginal perforation which has residual tympanic membrane in most of the regional. Human amniotic membrane is an ideal materials for repair of tympanic membrane.

[Clinical study of 26 patients with osteoma in the external].

OBJECTIVE: To summarize the experience of diagnosis and treatment on osteoma in the external auditory canal. METHOD: Retrospective study were undertaken in 26 patients with osteoma in the external auditory canal operated in author's unit. RESULT: Osteomas were removed through interauricular approach in all patients and confirmed by histopathological examination. The hearing of 22 patients with conductive hearing loss became normal after operation. The air conduction hearing threshold in 2 patients with mixed hearing loss improved average 15 dB and 20 dB respectively after operation. The follow up was more than 1 year, and no recurrence or complications had occurred. CONCLUSION: Osteoma in the external auditory canal is an uncommon benign lesion. The method of choice in diagnosis is temporal bone CT scan. Osteoma must be distinguished from exostosis in the external auditory canal. Osteoma is confirmed by pathological diagnosis and surgery is the only method for treatment.

[Effect of anteroposterior cricoid split on cartilage growth in rabbits].

OBJECTIVE: To investigate the effect of the anteroposterior cricoid split on cartilage growth. METHOD: The rabbits were killed 8 months after the surgery of anteroposterior cricoid split. The larynxes were harvested and the cross-sectional area of the cricoid cartilage were calculated. RESULT: There was no significant difference in the cross-sectional area of the cricoid cartilage of these three groups. CONCLUSION: The anteroposterior cricoid split might have no adverse effect on subsequent growth of cricoid cartilage.

[Quarter section cricoid split: its effect on cartilage growth in rabbits].

OBJECTIVE: To investigate the effect of the quarter-section cricoid split on cartilage growth. METHOD: The rabbits were killed 8 months after surgery of anterior, anteroposterior and quarter section cricoid split. The larynxes were harvested and the cross sectional areas of the cricoid cartilage were calculated. RESULT: There was no significant in the cross sectional area of the cricoid cartilage of any of the four groups. CONCLUSION: The quarter section cricoid split has no adverse effect on subsequent growth of cricoid cartilage and animals.

[Experimental study of tracheal defect repair with shape-memory titanium-nickel alloy net].

OBJECTIVE: To investigate the feasibility of trachea defect repair with "C" shape shape-memory titanium-nickel alloy net (CSSMAN). METHOD: The CSSMAN substitute for the tracheal cartilage and the skin tube for the tracheal mucosa in order to form a new "trachea" shape structure to repair the mongrel dogs trachea defect. RESULT: Four dogs were successfully decannulate, computerized tomography (CT) examination and fibrotracheoscopy examination showed the CSSMAN located perfectly and the airway is wide enough for breath. One dog failed to decannulate due to the infection. CONCLUSION: It is a promising choice to repair the trachea defect with CSSMAN by two-stage procedure.

[Experimental study on laryngeal cartilage defects repair with differently preserved allogeneic cartilages transplantation].

OBJECTIVE: To study the effect of laryngeal cartilage defect repair with differently preserved allogeneic cartilage grafts. METHODS: 16 New Zealand white rabbits were used and divided into two groups. A 6 mm x 3 mm x 1 mm whole thickness cartilage defect was made in each side of the thyroid cartilage of each rabbit. In group one, the tissue-cultured cartilage grafts, preserved in RPMI-1640 medium for 30 days, were implanted in the left defects and the 4% formaldehyde preserved cartilage grafts for 30 days were implanted in the right defects. Fresh autogenous and allogeneic grafts were seprately transplanted into the right and left thyroid cartilage defects of the other group. Thyroid cartilages were taken out at 7, 30, 180 and 360 days after implantation. Samples were observed by macroscopy and prepared for hematoxylin and eosin (H&E) staining and immunohistochemical examination. RESULTS: No marked changes in form and volume were found in the fresh allografts and RPMI-1640 cultured cartilage grafts. The same as the autogenous cartilages, the defects of thyroid cartilage were successfully repaired by the fresh allografts and RPMI-1640 cultured cartilages. Whereas 4% formaldehyde preserved cartilage grafts were completely absorbed and replaced by cicatricial tissues in the thyroid cartilage defects. Histological observation showed that severe inflammatory cellular infiltration in the formaldehyde preserved cartilages at 7 and 30 days. The cartilage matrixes were resorpted and the chondrocytes showed degenerative change. Finally they were replaced by fibrous connective tissue at 360 days. In the RPMI-1640 cultured and fresh allogeneic cartilages only a little inflammatory cellular infiltration was observed and the cartilage matrixes were almost normal from 7 to 360 days. CONCLUSION: It is clinically feasible to use allogeneic grafts stored in RPMI-1640 medium or fresh allogeneic cartilage grafts for repairing laryngeal cartilage defects.

[Anteroposterior cricoid split interposition grafting for severe glottic and subglottic stenosis].

OBJECTIVE: To study the effect of anterior and posterior cricoid splitting interposition grafting for severe glottic and subglottic stenosis. METHODS: This is a retrospective study, from 1991 to 2001 years, 25 patients (male 15, female 10, aged 9 to 46 years) with severe glottic and subglottic stenosis were operated with anterior and posterior cricoid splitting interposition grafting method at Tangdu Hospital. All of 25 patients were tracheostomy dependent before reconstruction. 19 patients had previously undergone 1 to 7 (average 2) surgical procedures. The surgical technique consisted of laryngotracheostomy, cricoid lamina midline vertical incision; rib cartilage graft (17 cases), muscular fasciae, perichondrium or split-thickness skin graft (15 cases), pedicle arytenoid cartilage graft (2 cases) and thyroid cartilage graft (1 case) interposition and silicon T-tube stenting for 3 to 6 months. RESULTS: Twenty-four patients (96%) were successfully decannulated and got an effective phonation. One patient failed decannulation. The follow-up period ranged from 1 to 10 years. All of the 24 patients had a stable airway and effective phonation. CONCLUSIONS: The anteroposterior cricoid split interposition graft technique was a safe and effective method for the treatment of severe glottic and subglottic stenosis. Careful split of the cricoid, avoiding injury of esophageal musculature, careful hemostasis, a tight suture graft and using stent were the keys of successful operation.