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Quantification of deposition of neutrophilic granulocytes on vascular grafts in dogs with 111In-labeled granulocytes
ABSTRACTS James
S. T. Yao,
M.D.,
Abstracts
Section
Editor
Quantification of deposition of neutrophilic granulocytes on vascular grafts in dogs with “%-labeled granulocytes Dewanjee MK, Solis E, Mackey ST, et al. Mayo Clin Proc 1983; 601173-9. The authors describe a new radioisotopic technique for measuring deposition of neutrophilic granulocytes on Gore-Tex and saphenous vein grafts in a canine model. The importance in studying this is that granulocytes have been implicated in a variety of graft functions including phagocytic removal of thrombus, early foreign body reaction, and perhaps of greatest significance, inhibition of graft endothelial coverage. Pure granulocytes were separated from whole blood and labeled with “‘In-tropolone in plasma. Dogs that had undergone previous bilateral femoral artery replacement (femoral vein on one side and Gore-Tex on the other) were injected with labeled granulocytes, and 2 hours after reperfLsion, the grafts were harvested and cut into several segments for study of anastomoses and midsections. The results indicated that the midsections of Gore-Tex grafts retained more granulocytes than the midsections of vein grafts. In vein grafts the anastomotic areas retained more granulocytes than the midsections; however, the opposite was found in the Gore-Tex grafts. The impact of this investigative technique may play a crucial role in the future for evaluation of improved cardiovascular prostheses and vascular grafts. Peter Kalvnan, M.D. New York Medical College
Carotid bifurcation atherosclerosis. Quantitative correlation of plaque localization with flow velocity profiles and wall shear stress Zarins CK, Giddens DP, Bharadvaj BK, et al. Circ Res 1983; 53:502-14. The authors report on their experimental work in the assessment of nonstenotic, asymptomatic intimal plaques in 12 human carotid artery bifurcations obtained at autopsy and compared with distribution of flow patterns, flow velocity profiles, and shear stresses in corresponding scale models. The postmortem specimens were fixed while distended to restore normal in vivo length, diameter, and configuration. Angiograms were taken to measure branch angles and diameters, while a laser-Doppler anemometer was used to determine flow velocity profiles and shear stresses. Flow patterns were visualized by hydrogen bubble and dye-washout techniques in the three-dimensional model. Intimal thickening was greatest and consistently eccentric in the carotid sinus. The intima was thinnest along
the inner wall and thickest on the outer wall of the internal carotid artery model. Along the outer wall of the carotid model the pattern of flow was complex and included a region of separation and reversal of axial flow, as well as counter-rotating helical trajectory. The authors conclude that in the human carotid bifurcation, regions of moderate to high stress, where flow remains unidirectional and axially aligned, intimal thickening is relatively sparse. Conversely, maximal intimdl thickening and atherosclerosis develop in regions of reduced wall shear stress, flow separation, flow reversal, and departure from axially aligned, unidirectional flow as in the proximal internal carotid artery outer wall. David Rosenthal, M.D. Geoyia Baptist Medical Center-Medical Colltye of ‘Choyqia
Percutaneous transluminal angioplasty for pediatric renovascular hypertension Stanley P, Hieshima G, Mehringer M. Radiolobv 1984; 153: 101-4. Five children, two boys and three girls. 22 months to 12 years in age presented with severe renovascular hypertension. Coma and congestive heart failure were each present in one patient. The average blood pressure at thr: time of admission was 197/126 mm Hg for this group of patients. All underwent arteriography because of inadequate blood pressure control with medical therapy. Four of the five patients had unilateral renal artery stenotic disease, whereas the fifth presented with an anastomotic stricture after bilateral patch angioplasty was performed co treat renal artery stenosis. The main renal arterv was involved in the fiiih patient. Percutaneous transluminal angioplasty was used to treat all patients. Procedures were p&?>rmed with the patient under sedation with meperidine and promethazine. Transfemoral placement of a 5.5 Fr or 6 Fr. sheath was used to facilitate catheter exchange. A 5 Fr. balloon angioplasty catheter was positioned across the stenosis and inflated to 4 atmospheres for 20 seconds. After dilation, flush aortography was obtained to demonstrate the angioplasty result. Heparinization (100 U/kg\ was used during the procedure but no long-term anticoagulants or antiplatelet agents were used. A satisfactory arteiiographic appearance was present after dilation in all patients. At the time of discharge from the hospital (48 to 72 hours), all five patients were normotensive. One patient de\,eloped recurrent hypertension 10 months later. Follow-up arteriography revealed a reurrent stenosis of the main renal artery at the site of the original lesion. This Icslon was subsequently treated by standard operative theraps. The remaining four patients remained normotensi1.e 1 to 2 years after dilation. No late follow-up arteriographic stud677
S. T. Yao,
M.D.,
Abstracts
Section
Editor
Quantification of deposition of neutrophilic granulocytes on vascular grafts in dogs with “%-labeled granulocytes Dewanjee MK, Solis E, Mackey ST, et al. Mayo Clin Proc 1983; 601173-9. The authors describe a new radioisotopic technique for measuring deposition of neutrophilic granulocytes on Gore-Tex and saphenous vein grafts in a canine model. The importance in studying this is that granulocytes have been implicated in a variety of graft functions including phagocytic removal of thrombus, early foreign body reaction, and perhaps of greatest significance, inhibition of graft endothelial coverage. Pure granulocytes were separated from whole blood and labeled with “‘In-tropolone in plasma. Dogs that had undergone previous bilateral femoral artery replacement (femoral vein on one side and Gore-Tex on the other) were injected with labeled granulocytes, and 2 hours after reperfLsion, the grafts were harvested and cut into several segments for study of anastomoses and midsections. The results indicated that the midsections of Gore-Tex grafts retained more granulocytes than the midsections of vein grafts. In vein grafts the anastomotic areas retained more granulocytes than the midsections; however, the opposite was found in the Gore-Tex grafts. The impact of this investigative technique may play a crucial role in the future for evaluation of improved cardiovascular prostheses and vascular grafts. Peter Kalvnan, M.D. New York Medical College
Carotid bifurcation atherosclerosis. Quantitative correlation of plaque localization with flow velocity profiles and wall shear stress Zarins CK, Giddens DP, Bharadvaj BK, et al. Circ Res 1983; 53:502-14. The authors report on their experimental work in the assessment of nonstenotic, asymptomatic intimal plaques in 12 human carotid artery bifurcations obtained at autopsy and compared with distribution of flow patterns, flow velocity profiles, and shear stresses in corresponding scale models. The postmortem specimens were fixed while distended to restore normal in vivo length, diameter, and configuration. Angiograms were taken to measure branch angles and diameters, while a laser-Doppler anemometer was used to determine flow velocity profiles and shear stresses. Flow patterns were visualized by hydrogen bubble and dye-washout techniques in the three-dimensional model. Intimal thickening was greatest and consistently eccentric in the carotid sinus. The intima was thinnest along
the inner wall and thickest on the outer wall of the internal carotid artery model. Along the outer wall of the carotid model the pattern of flow was complex and included a region of separation and reversal of axial flow, as well as counter-rotating helical trajectory. The authors conclude that in the human carotid bifurcation, regions of moderate to high stress, where flow remains unidirectional and axially aligned, intimal thickening is relatively sparse. Conversely, maximal intimdl thickening and atherosclerosis develop in regions of reduced wall shear stress, flow separation, flow reversal, and departure from axially aligned, unidirectional flow as in the proximal internal carotid artery outer wall. David Rosenthal, M.D. Geoyia Baptist Medical Center-Medical Colltye of ‘Choyqia
Percutaneous transluminal angioplasty for pediatric renovascular hypertension Stanley P, Hieshima G, Mehringer M. Radiolobv 1984; 153: 101-4. Five children, two boys and three girls. 22 months to 12 years in age presented with severe renovascular hypertension. Coma and congestive heart failure were each present in one patient. The average blood pressure at thr: time of admission was 197/126 mm Hg for this group of patients. All underwent arteriography because of inadequate blood pressure control with medical therapy. Four of the five patients had unilateral renal artery stenotic disease, whereas the fifth presented with an anastomotic stricture after bilateral patch angioplasty was performed co treat renal artery stenosis. The main renal arterv was involved in the fiiih patient. Percutaneous transluminal angioplasty was used to treat all patients. Procedures were p&?>rmed with the patient under sedation with meperidine and promethazine. Transfemoral placement of a 5.5 Fr or 6 Fr. sheath was used to facilitate catheter exchange. A 5 Fr. balloon angioplasty catheter was positioned across the stenosis and inflated to 4 atmospheres for 20 seconds. After dilation, flush aortography was obtained to demonstrate the angioplasty result. Heparinization (100 U/kg\ was used during the procedure but no long-term anticoagulants or antiplatelet agents were used. A satisfactory arteiiographic appearance was present after dilation in all patients. At the time of discharge from the hospital (48 to 72 hours), all five patients were normotensive. One patient de\,eloped recurrent hypertension 10 months later. Follow-up arteriography revealed a reurrent stenosis of the main renal artery at the site of the original lesion. This Icslon was subsequently treated by standard operative theraps. The remaining four patients remained normotensi1.e 1 to 2 years after dilation. No late follow-up arteriographic stud677