124
Journa2 of VASCULAR SURGERY
Letters to the Editors
5. Smith R, Estridge M. Neurologic complications of head and neck manipulations. JAMA 1962;182:528-31. 6. Miller R, Burton R. Stroke following chiropractic manipulation of the spine. JAMA 1974;229:189-90.
Carotid biaxillary bypass: A new operation To the Editors:
We present a report of a man who sought treatment for arm pain and coldness. CASE R E P O R T
The effect o f varying fibronectin concentration on the attachment o f endothelial cells to polytetrafluoroethylene vascular grafts To the Editors:
We read with interest the paper entitled, "The effect of varying fibronectin concentration on the attachment of endothelial cells to polytetrafluoroethylene vascular grafts", by B u d d e t al. in the JOURNAL OF VASCULARSURGERY (1990;12:126-30) in which the authors claim that no previous studies had been performed to determine the most effective concentration of fibronectin as a matrix on expanded polytetrafluoroethylene (ePTFE) for endothelial cell attachment. This is untrue since we published our results 6 months earlier in which we clearly described the optimum concentration of fibronectin for endothelial cell adherence to ePTFE using adult human endothelial ceils? In our studies attachment to ePTFE was measured by use of iodine 125 radiolabelled protein at different concentrations and for different time periods. The absolute amount offibronectin bound to the graft increased with the concentration used in coating (p < 0.001) and also with time (p < 0.01); for example, at 50 ~g/ml, 90 minutes of incubation produced a molecular attachment of 4.0 × 1011/cm2 of graft. However, its percentage attachment decreased with a rise in concentration (p < 0.001). After an initial loss of 22% in 30 minutes, the fibronectin-graft bond was found to be stable when exposed to a shear stress produced by flow at 200 ml/min. No significant difference in the cell adherence could be found in grafts coated with fibronectin concentrations of 50, 150, and 250 ~g/ml although it was significantly less at 10 and 25 ~g/ml
A 51-year-old white man sought treatment at the emergency department for a 24-hour-history of bilateral arm pain and coldness. Seven years ago he had multiple vascular procedures for left subclavian artery occlusion and brachial artery embolus. A right-to-left axillary artery bypass had also been done. The patient was a nonsmoker, nondiabetic, and normolipidemic. Physical examination showed no palpable pulses in either upper extremity, minimal Doppler flow in left arm vessels, and diminished flow in right arm vessels. An arteriogram revealed bilateral proximal subclavian artery occlusion with reconstitution of the axillary artery bilaterally. There was hemodynamically significant left common carotid artery stenosis at the origin (Fig. 1). The patient underwent right common carotid to bilateral axillary bypass. The patient underwent an arteriogram confirming patency of the bypass (Fig. 2). The bypass continued to be patent on clinical and noninvasive examination until the time of his death 16 months after implantation. The patient died of cancer of the pancreas. A transverse incision was made supraclavicularly. The right common carotid artery was dissected for approximately 5 cm. Next, an incision was made infraclavicularly on the right side. The axillary artery was dissected for
(p < 0.05). Although we agree with their findings, it would have been more appropriate had they measured the molecular attachment of fibronectin to ePTFE and used adult human endothelial cells, as in our experiments, which is more appropriate to the clinical situation. M. G. Walker tL IC Vohra G. J. L. Thomson H. Sharma H. M. H. Carr
Departments of Vascular Surgery and Medical Bio-Physics Manchester Royal Infirmary and Manchester Medical School Oxford Rd. Manchester M13 9WL United Kingdom REFERENCE 1. Vohra RK, Thomson GJL, Sharma H, Carr HMH, Walker MG. Fibronectin coating of expanded polytetrafluoroethylene (ePTFE) grafts and its role in endothelial seeding. Artif Org 1990;14:41-5.
Fig. 1. Both subclavian arteries are occluded. Arrow shows hemodynamically significant stenosis at the origin of the left common carotid artery.
Journa2 of VASCULAR SURGERY
Letters to the Editors
5. Smith R, Estridge M. Neurologic complications of head and neck manipulations. JAMA 1962;182:528-31. 6. Miller R, Burton R. Stroke following chiropractic manipulation of the spine. JAMA 1974;229:189-90.
Carotid biaxillary bypass: A new operation To the Editors:
We present a report of a man who sought treatment for arm pain and coldness. CASE R E P O R T
The effect o f varying fibronectin concentration on the attachment o f endothelial cells to polytetrafluoroethylene vascular grafts To the Editors:
We read with interest the paper entitled, "The effect of varying fibronectin concentration on the attachment of endothelial cells to polytetrafluoroethylene vascular grafts", by B u d d e t al. in the JOURNAL OF VASCULARSURGERY (1990;12:126-30) in which the authors claim that no previous studies had been performed to determine the most effective concentration of fibronectin as a matrix on expanded polytetrafluoroethylene (ePTFE) for endothelial cell attachment. This is untrue since we published our results 6 months earlier in which we clearly described the optimum concentration of fibronectin for endothelial cell adherence to ePTFE using adult human endothelial ceils? In our studies attachment to ePTFE was measured by use of iodine 125 radiolabelled protein at different concentrations and for different time periods. The absolute amount offibronectin bound to the graft increased with the concentration used in coating (p < 0.001) and also with time (p < 0.01); for example, at 50 ~g/ml, 90 minutes of incubation produced a molecular attachment of 4.0 × 1011/cm2 of graft. However, its percentage attachment decreased with a rise in concentration (p < 0.001). After an initial loss of 22% in 30 minutes, the fibronectin-graft bond was found to be stable when exposed to a shear stress produced by flow at 200 ml/min. No significant difference in the cell adherence could be found in grafts coated with fibronectin concentrations of 50, 150, and 250 ~g/ml although it was significantly less at 10 and 25 ~g/ml
A 51-year-old white man sought treatment at the emergency department for a 24-hour-history of bilateral arm pain and coldness. Seven years ago he had multiple vascular procedures for left subclavian artery occlusion and brachial artery embolus. A right-to-left axillary artery bypass had also been done. The patient was a nonsmoker, nondiabetic, and normolipidemic. Physical examination showed no palpable pulses in either upper extremity, minimal Doppler flow in left arm vessels, and diminished flow in right arm vessels. An arteriogram revealed bilateral proximal subclavian artery occlusion with reconstitution of the axillary artery bilaterally. There was hemodynamically significant left common carotid artery stenosis at the origin (Fig. 1). The patient underwent right common carotid to bilateral axillary bypass. The patient underwent an arteriogram confirming patency of the bypass (Fig. 2). The bypass continued to be patent on clinical and noninvasive examination until the time of his death 16 months after implantation. The patient died of cancer of the pancreas. A transverse incision was made supraclavicularly. The right common carotid artery was dissected for approximately 5 cm. Next, an incision was made infraclavicularly on the right side. The axillary artery was dissected for
(p < 0.05). Although we agree with their findings, it would have been more appropriate had they measured the molecular attachment of fibronectin to ePTFE and used adult human endothelial cells, as in our experiments, which is more appropriate to the clinical situation. M. G. Walker tL IC Vohra G. J. L. Thomson H. Sharma H. M. H. Carr
Departments of Vascular Surgery and Medical Bio-Physics Manchester Royal Infirmary and Manchester Medical School Oxford Rd. Manchester M13 9WL United Kingdom REFERENCE 1. Vohra RK, Thomson GJL, Sharma H, Carr HMH, Walker MG. Fibronectin coating of expanded polytetrafluoroethylene (ePTFE) grafts and its role in endothelial seeding. Artif Org 1990;14:41-5.
Fig. 1. Both subclavian arteries are occluded. Arrow shows hemodynamically significant stenosis at the origin of the left common carotid artery.
