Study on decellularized laryngeal scaffold in dogs / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To explore the survivorship and character of decellularized laryngeal scaffold in pectoralis major muscle flap in canine.</p><p><b>METHODS</b>Eighteen donor larynx in experimental group were decellularized by perfusing sodium dodecyl sulphate. Three of them were used to detect the character of histology. The other fifteen ones were embedded in right pectoralis major muscle flap of acceptor canine. Donor larynx in control group were not perfused. Other experimental procedure was the same as experimental group. The specimens were harvested at two weeks, one month and two months after operation, respectively. Macroscopic view, histological examination and trypan blue staining were performed in the experimental group and control group.</p><p><b>RESULTS</b>The size of the specimens decreased remarkably into disappearance in control group, there was statistical significance between the experimental group and the control group (which used least significant difference t test P < 0.05). There was only little neutrophils and lymphocytes infiltrating around the laryngeal scaffold at 2 weeks in the experimental group. One month after operation, loose connective tissue begin to form around the laryngeal scaffold. After two months of transplantation, the connective tissue became thicker and the number of blood vessels increased than before. There was a large number of lymphocytes and neutrophil infiltration around the laryngeal specimens in the control group at 2nd week. The perichondrium in the control group was damaged at one month post operation. The cartilage cells could not be detected two months after surgery. The survival rate of cartilage cell between experimental group (86.8% ± 3.2%) and the control group (88.6% ± 3.1%) did not show statistical significance before implantation (χ(2) = 0.19, P > 0.05). The survival rate of cartilage cell decreased insignificantly in experimental group while the survival rate declined obviously in the control group at two weeks and one month after operation, the difference had statistical significance (χ(2) were respectively 5.52 and 20.55, P were respectively < 0.05 and < 0.01), the survival rate of cartilage cell in experimental group was (65.8% ± 2.6%) at two months after operation, while the cartilage cell all disappeared in control group.</p><p><b>CONCLUSIONS</b>Perfused decellularation technique can construct a low immunogenicity laryngeal cartilage scaffold which can survive in the chest muscle package and establish a good blood supplement. The decellularized laryngeal scaffold could be used as a biological scaffold for whole laryngeal reconstruction.</p>

Immunological study on decellularized whole laryngeal scaffold / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To evaluate the immunogenicity of the decellularized laryngeal scaffold.</p><p><b>METHODS</b>Twelve perfused, decellularized laryngeal scaffolds were obtained from rabbits through common carotid artery perfusion with detergents. The twelve decellularized laryngeal scaffolds and the twelve fresh larynxes were then implanted in para-laryngeal muscles of rabbits and harvested after two weeks, four weeks, twelve weeks and twenty-four weeks, respectively. Macroscopic view, histological examination and lymphocyte infiltration test were performed.</p><p><b>RESULTS</b>The decellularized larynxes were implanted and preserved the laryngeal extracellular matrix and laryngeal architecture. The decellularized larynx did not show obvious immunological rejection after implanted into the para-laryngeal muscles of the recipient rabbits. The volume of implanted larynx became smaller but retained cartilage scaffold. The larynxes in the control group presented the serious immunological rejection and the majority tissues of the larynxes were disintegrated and substituted by the fibrous connective tissues after four weeks. The peripheral tissues were damaged and necrotic at different degrees. The quantity of the lymphocyte infiltration in the control group was higher than that in the experiment group and the result had the statistical significance (P < 0.01).</p><p><b>CONCLUSIONS</b>Perfused, decellularized technique can construct a low immune laryngeal cartilage scaffold which could be a satisfactory material for laryngeal repair.</p>

A preliminary study on the preparation of perfusion-decellularized laryngeal scaffold and the feasibility of laryngeal muscle reconstruction / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To prepare a decellularized whole laryngeal scaffold by utilizing a perfusion-decellularized technique, reseed cells on it, and construct decellularized laryngeal muscles.</p><p><b>METHODS</b>Perfusion decellularized larynxes were obtained by common carotid arterious perfusion with detergents. Then they were performed by macroscopic view, histological examination, scanning electron microscopy (SEM) and cartilage viability. Decellularized laryngeal scaffold were then reseeded with inducted mesenchymal stem cells (MSCs). Composites were transferred into greater omentums of rabbits after one day's adherence and harvested after eight weeks. Macroscopic view, histological examination and immunohistochemistry were performed.</p><p><b>RESULTS</b>Perfusion larynxes became transparent after two hours. Histology and SEM indicated that perfusion method showed better decullularized effect. More vintages and collagen fibers but no intact cell or nuclei were retained in the decellularized matrix. Porosity measured by Image pro plus 6.0 was 80.4% +/- 3.2% (x +/- s). Chondrocyte vitality assay indicated chondrocyte vitality rate in the perfusion group was 86.9% +/- 1.5%. After eight weeks, vascularization formed and integrated cartilage frameworks still remained. Histological examination could clearly show the presence of muscle bundles and vessels. Immunohistochemical examination indicated that sarcomeric-alpha actin expressed positively in corresponding areas.</p><p><b>CONCLUSIONS</b>It is feasible to reseed MSCs into the decellularized laryngeal muscle matrix for constructing tissue-engineered laryngeal muscles. This in vivo maturation into the omentum could be the first step before in situ implantation of the construct.</p>

Experience of diagnosis and treatment for cervical tracheoesophageal fistula complicated with laryngotracheal stenosis / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To explore the treatment of cervical tracheoesophageal fistula (TEF) with complicated or remnant laryngotracheal stenosis (LTS) and anterior neck defect (AND).</p><p><b>METHODS</b>From 1980 to 2007, 14 patients were diagnosed as TEF. Among them, 9 patients had complicated or remnant LTS, 3 patients had complicated AND, and 2 patients had TEF which were induced by Nickel-Titanium alloy mesh stent for treating benign esophageal stricture. All these patients were retrospectively studied in Tangdu Hospital. Treatment consisted of conservative therapy of TEF, staged surgical repair of TEF and laryngotracheal reconstruction according to the dimension (small or large) of TEF and complications.</p><p><b>RESULTS</b>Four patients with small TEF (2 - 3 mm length) complicated LTS underwent laryngotracheal reconstruction stented with silicone T tube and TEF was adopted conservative treatment. The TEF and LTS were healed. Six patients with larger TEF (10 - 25 mm length) were repaired by staged surgical repair of TEF and laryngotracheal reconstruction. Among them, 3 cases had complicated LTS and AND, 2 cases had recent LTS and 1 case had TEF without complication. Two patients had TEF and LTS, whose TEF healed before laryngotracheal reconstruction, the remnant LTS were reconstructed and healed. During the follow-up ranged from one to ten years, 12 patients were successfully treated without complications. One patient with TEF and LTS was treated only LTS because of a segment of esophagus was closed and treated with esophagogastrostomy in the department of thoracic surgery after LTS was successfully reconstructed and cured. One patient died of bleeding and asphyxia induced by the Nickel-Titanium alloy stent because of the stent had not been taken out.</p><p><b>CONCLUSION</b>The small cervical TEF complicated or remnant LTS can be treated by laryngotracheal reconstruction and conservative treatment of TEF at the same time. A larger TEF complicated LTS should be treated by staged repair of TEF and LTS.</p>

Experimental study on tracheal reconstruction using porous titanium rings and free skin flap / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To investigate the feasibility and efficacy of the cervical tracheal reconstruction using porous titanium rings and free skin flap.</p><p><b>METHODS</b>Twelve adult mongrel dogs were divided randomly into group I and group lI. A segment of cervical trachea (25 mm, 4 rings, about 2/3 circumference) was resected and a rectangular free skin flap was harvested from abdomen. The flap was sutured to the defect part and supported with two porous titanium rings (group I) or without (group II ). X ray and fiberscopic examinations were performed at the end of the first and the sixth months postoperatively. After six months the dogs were sacrificed and the grafts were examined macroscopically and microscopically.</p><p><b>RESULTS</b>In group I, one dog was sacrificed for wound infection and skin flap necrosis with deflexion of titanium rings in the fifth day postoperatively. The other 5 of 6 survived until the end of six months. X-ray examination showed titanium rings were fastened well without displacement or deformity. Through fiberscopy, the trachea luminal patency was maintained well without stricture, shrinkage or necrosis. Histologic examination showed most of the inner surface of the flap was covered with ciliated columnar epithelium. In group II, 3 of 6 dogs died of suffocation within 24 hours postoperatively. The remaining 3 dogs survived from 7 to 16 days with dyspnea and fiberscopic examination showed narrowed trachea lumens.</p><p><b>CONCLUSIONS</b>Porous titanium rings could recreate the framework for cervical tracheal reconstruction using free skin flap and would be one of the options for tracheal reconstruction.</p>