Comparison of zero-stress state of ascending aorta and pulmonary trunk between human and swine in vascular tissue reconstruction

Minghua YU; Tiezhu HUANG; Wenchun LI; Peijun WANG

ABSTRACT

BACKGROUND:

Due to the source of conspecific heart transplanted organ is limited and it becomes more and more deficient, and porcine cardiovascular system and haemodynamics are very similar to that of human being, therefore, domestic and foreign scholars have paid more attention on the heterogeneic heart transplantation from swine to human, and there are more and more basic studies about it.

OBJECTIVE:

To compare the zero-stress state of ascending aorta and pulmonary artery trunk between swine of different months and healthy persons, which provides necessary vascular tissue reconstruction basis for anastomosing vessel of heterogeneic heart transplantation from swine to human being.

DESIGN:

Open experiment.

SETTING:

Laboratory of Biomechanics, Yunyang Medical College.MATERIALS This experiment was carried out at the Laboratory of Biomechanics, Yunyang Medical College from October 2001 to September 2002. Human heart specimens were chosen from 6 male adult corpses who had no visible manifestation of cardiovascular diseases, aged 18 to 30 years. Informed consents were obtained from all the relatives. Totally 42 conspecific swine, aged one month, were also chosen and divided into 7 groups, named as 1,2,3,4,5,6 and ＞ 6 months groups respectively, with 6 in each group. Swine were anesthetized at 1,2,3,4,5,6,＞ 6 months respectively and sacrificed in each group.

METHODS:

The corresponding ascending aorta and pulmonary artery trunk were dissected and isolated. Each arterial anterior wall was labeled in situ with coloring pen, and then artery was shifted into the oxygen-saturated Kreb's solution. Five isometric vascular rings were divided along the axial direction, then each vascular ring was cut open along the radial direction. Opening angle of each vascular ring at zerostress state was measured and recorded by computer 20 minutes later(The included angel formed through connecting the middle point of inner wall of open vascular plane and two end points of inner wall). The experiment was conducted at room temperature 20-30 ℃. All the procedures of vascular samples were performed within 24 hours after subjects died.MAIN OUTCOME

MEASURES:

Measuring results of opening angle of ascending aorta and pulmonary trunk at zero-stress state of swine at different months and human being.

RESULTS:

①Comparison of measuring results of opening angle of ascending aorta and pulmonary trunk between swine at different months and human being Opening angle of ascending aorta of human being increased from (100.4±12.8)°at proximal end to (152.8±18.6)°at distal end. Opening angle of swine at different months increased from about 68°at proximal end to about 130°at distal end; Opening angel of pulmonary artery trunk of human being did not changed significantly along axial direction, and opening angel of pulmonary artery trunk of swine at different months increased from about 65° at proximal end to about 125°at distal end. There was significant difference of opening angle of ascending aorta and pulmonary trunk at zero-stress state between human being and swine (P=0.028 ＜ 0.05).But the opening angle of ascending aorta of human being was similar at the second segment to at the fourth and fifth segments of swine of different ages; Opening angle of each segment of pulmonary artery trunk of human being was close to that of proximal end (first and second segments) ofpulmonary artery trunk of swine.② Comparison of measuring results of ascending aorta and pulmonary artery trunk at zero-stress state of swine at different months Opening angle of ascending aorta and pulmonary artery trunk of swine did not changed with the increase of age (P=-0.063 ＞ 0.05).

CONCLUSION:

Opening angels of ascending aorta and pulmonary artery trunk at zero-stress state are close in some segments between human being and swine, suggesting that corresponding ascending aorta or pulmonary artery trunk can mutually anastomose in some segments in the heterogeneic heart transplantation from swine to human, and the effect of age is not significant in vascular reconstruction.