Zhang Jinshan,Li Long.Relationship between portal vein patency and changes of portal hemodynamics and portal venous pathology[J].Journal of Clinical Pediatric Surgery,,21():980-986.[doi:10.3760/cma.j.cn101785-202105061-014]
Relationship between portal vein patency and changes of portal hemodynamics and portal venous pathology
- Keywords:
- Portal Vein; Physiopathology; Portal Vein; Injuries; Portal Vein; Hemodynamics; Portal Pressure; Animal Experimentation
- Abstract:
- Objective To explore the impact of portal vein patency on the changes of portal hemodynamics and portal venous pathology.Methods Eighteen New Zealand white rabbits were randomly divided into three groups of normal control (NC),extra-hepatic portal venous obstruction (EHPVO) and r-EHPVO (reversible extra-hepatic portal venous obstruction).They were created respectively by dissecting main portal vein after laparotomy,narrowing main portal vein with a cannula and removing the cannula at Day 14 after EHPVO modeling.Portal vein pressure,blood flow velocity and diameter of portal vein were measured at Day 14/28.Shear stress of portal vein was calculated by shear stress τ=4Q×η/π×r3 (η is fluid viscosity,Q fluid flow rate & r radius).Circumferential stress of portal vein was calculated by circumferential stress T=ΔP×r/h (r radius of portal vein,ΔP transmural pressure gradient & h wall thickness of portal vein).At Day 28,main portal vein was collected for pathological examination and thickness/area of intima and media were measured by Image J software.Shear stress,circumferential stress,intima and media thickness,intima area/media area (I/M) and intima area/sum of intima and media area [I/(I+M)] were compared among three groups.The correlations between shear stress and intima thickness and circumferential stress and media thickness were analyzed.Results At Day 28,as compared with NC group,shear stress dropped significantly [EHPVO vs.NC:(0.392±0.041) Pa vs.(0.772±0.039) Pa,P<0.001;r-EHPVO vs.NC:(0.690±0.042) Pa vs.(0.772±0.039) Pa,P=0.009]and circumferential stress increased markedly [EHPVO vs.NC:(34.002±3.128) kPa vs.(15.706±0.867) kPa,P<0.001;r-EHPVO vs.NC:(22.329±3.350) kPa vs.(15.706±0.867) kPa,P=0.002]in EHPVO and r-EHPVO groups;as compared with EHPVO group,shear stress spiked significantly [(0.690±0.042) Pa vs.(0.392±0.041) Pa,P<0.001]and circumferential stress declined markedly in r-EHPVO group[(22.329±3.350) kPa vs.(34.002±3.128) kPa,P<0.001].As compared with r-EHPVO group at Day 14 before removing cannula,shear stress significantly increased [(0.690±0.042) Pa vs.(0.430±0.072) Pa,t=-8.079,P<0.001]and circumferential stress dropped markedly in r-EHPVO group at Day 28 [(22.329±3.350) kPa vs.(37.640±2.774)kPa,t=7.373,P=0.001].However,shear and circumferential stresses showed no significant difference between r-EHPVO group at Day 28 and r-EHPVO group at Day 14 after removing cannula [shear stress:(0.690±0.042)Pa vs.(0.650±0.058)Pa,t=-1.112,P=0.317;Circumferential stress:(22.329±3.350) kPa vs.(26.988±2.139) kPa,t=2.532,P=0.052].Intimal thickness,I/M and I/(I+M) of EHPVO group were significantly higher than those of NC and r-EHPVO groups [intimal thickness:EHPVO vs.NC:(11.35±1.47) μm vs.(6.19±1.34) μm,P<0.001;EHPVO vs.r-EHPVO:(11.35±1.47) μm vs.(7.88±1.72) μm,P=0.001;I/M:EHPVO vs.NC:(0.156±0.019) vs.(0.100±0.020),P<0.001;EHPVO vs.r-EHPVO:(0.156±0.019) vs.(0.117±0.011),P=0.002;I/(I+M):EHPVO vs.NC:(0.135±0.014) vs.(0.091±0.016),P<0.001;EHPVO vs.r-EHPVO:(0.135±0.014) vs.(0.105±0.009),P=0.002].However,no difference existed in intimal thickness,I/M or I/(I+M) between NC and r-EHPVO groups [intimal thickness:(6.19±1.34) vs.(7.88±1.72) μm,P=0.071;I/M:(0.100±0.020) vs.(0.117±0.011),P=0.104;I/(I+M):(0.091±0.016) vs.(0.105±0.009),P=0.089].No significant difference existed in media thickness among three groups [(74.15±5.31) vs.(62.97±5.65) vs.(68.46±13.79) μm,P>0.05].A negative correlation existed between shear stress and intimal thickness(r=-0.799,P<0.001).And a positive correlation existed between circumferential stress and media thickness (r=0.792,P<0.001).Conclusion The patency of portal vein is significantly correlated with portal hemodynamics and intimal changes.Portal vein obstruction reduces shear stress and increases circumferential stress and intimal thickness.Restoring portal vein blood flow is beneficial to reverse these changes.
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Memo
收稿日期:2021-5-31。
基金项目:国家自然科学基金(81770595、82170679);首都儿科研究所所级基金(GZ-2021-09)
通讯作者:张金山,Email:zjs851@163.com