Repairing intrathoracic esophageal defect with autologous pulmonary tissue in dogs

Jungang ZHAO; Wenjun SHI; Yun HAN; Suning ZHANG

ABSTRACT

BACKGROUND:

Esophageal replacement or reconstruction should be performed after esophageal resection. There are still no suitable substitutes for esophagus if the conventional esophageal substitutes cannot be used.

OBJECTIVE:

To investigate the feasibility of applying a pulmonary tissue with vascular pedicle to repair the intrathoracic esophageal defect.

DESIGN:

A prospective animal investigation.

SETTING:

Department of Thoracic Surgery, Second Hospital Affiliated to China Medical University.MATERIALS This trial was carried out in the laboratory of Department of Thoracic Surgery, Second Hospital Affiliated to China Medical University during January 2003 to June 2004. Fourteen adult mongrel dogs of either gender, with body mass of 12 to 18 kg, were provided by Animal Room, Second Hospital Affiliated to China Medical University (License No.SYXK (Liao) 2003-0019).

METHODS:

Of 14 anesthetized dogs, the middle lobe of right lung was dissected and its right middle lobar bronchus was ligated without damaging pulmonary and bronchial vessels in order to make pulmonary flap. A part of full-layer intrathoracic esophageal wall was resected, which was 4 cm long and 1/2 to 2/3 circled esophageal wall. The defect was patched by pulmonary tissue with vascular pedicle which was inosculated with esophageal cross section. On the 3rd day after operation, intravenous transfusion was performed to maintain nutrition. Qn the 7th day after operation, the dogs were given oral liquid soft food gradually 2 weeks after the operation. The access to the food and the survival of dogs were observed. Every 2 dogs were sacrificed respectively at the 2nd, 4th, 6th, 8th and 10th postoperative weeks. To observe the healing of esophageal defect, light microscope, transmission electron microscope, esophagography and endoscope were used in this study.MArN OUTCOME

MEASURES:

①Survival situation and access to food of dogs after operation. ② The healing of esophageal defect of dogs.

RESULTS:

Three of fourteen dogs died within one week after operation. Eleven dogs survived. ① The survival and access to food of experimental dogs after operation One dog was alive without problems for more than 170 weeks. The living dogs could be fed orally on the 7th day after operation. ② The healing at esophageal defect of experimental dogsAt the 2nd week after operation, the esophageal defect was covered with collagen layer and inflammatory exudation. A little epithelization was observered at free edge of the anastomosis, which was 1 to 2 layers of stratified squamous epithelium cells. At the 4th to 6th weeks after operation, the internal surface of the defect was covered with 3 to 5 layers of stratified epithelium cells. At the 8th to 10th weeks after operation, the luminal surface of the defect was covered with 6 to 8 layers of stratified epithelium cells. The pathological changs of pulmonary flap mainly included pulmonary alveoli atelectasis and pulmonary fibrosis, and some inflammatory cells without infective focus were observed. In the transmission electron microscope examination, newborn stratified squamous epithelium cells were. found on the surface of pulmonary tissue flap at esophageal defect.

CONCLUSION:

It is feasible to repair the partial irregular intrathoracic esophageal defect with the autologous pulmonary flap in dogs.