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Asymptomatic high-grade internal carotid stenosis and ocular pneumoplethysmography
Volume 12 Number ]. lul,~ 1990
5. 6. "7. 8.
bosis of ifiofemoral vein. Surg Gynecol Obstet 1986;163: 111-6. Swedenborg J, Hagglof R, Jacobsson H, et al. Results of surgical treatment for iliofemoral venous thrombosis. Br J Surg 1986; 73:871-4. KiUewichLA, Bedford GR, Beach KW, Strandness DE. Spontaneous lysis of deep venous thrombi: rate and outcome. J VAsc SURG 1989;9:89-97. de Araujo Bessa IC. Femoral and iliofemoral thrombectomy to prevent chronic venous insufficiency. J Cardiovasc Surg 1986;27:443-6. Lindner DJ, Edwards JM, Phinney ES, Taylor LM, Porter JM. Long-term hemodynamic and clinical sequelae of lower extremity deep venous thrombosis. J VASCSUgG 1986;4:43642.
Asymptomatic high-grade internal carotid stenosis ,: =d ocular pneumoplethysmography To the Editors:
A recent article in the JOUWNALby Moneta et al. 1 de"scribes the stratification of asymptomatic high-grade internal carotid stenosis by duplex spectral analysis. The principal role ofultrasonographic imaging and spectral analysis in the assessment o f carotid lesions is incontrovertible. A recent report from this institution supports this conclusion. 2 However, this tool is not perfect, and clinically usefi,tl information is provided by ocular pneumoplethysmography (OPG-Gee), especially in the overall evaluation of the "asymptomatic severe carotid stenosis, which implies adequate collateral hemodynamic compensation and embologenic silence. Intracranial hemodynamic compensation is not assured if systemic hypotension is encountered, which is not uncommon during coronary procedures, other arterial re_pairs, and major orthopedic and visceral ablative operations. Success o f any of these procedures complicated by ~ oke as a result of thrombotic occlusion of an asymptomatic high-grade carotid lesion is devastating to all concerned. Any decision to consciously ignore the possibility of such a lesion before the planned procedure has serious ethical and legal implications, not the least of which is ~inforrned consent. The logistics of screening all such candidates with carotid duplex interrogation is prohibitive. The OPG-Gee is a rapid, simple, relatively inexpensive screening device for this purpose. Even when this test is false negative in the presence of an asymptomatic severe carotid lesion, it is true negative in regard to the liemodynamic consequences of this lesion.
Letters to the editor
107
The OPG-Gee was originally designed and developed for use with proximal common carotid compression to noninvasively ascertain the collateral ophthalmic systolic pressure? This assessment compares closely with operative internal carotid systolic pressure measurements, both direct and collateral. 4,s Safety of proximal common carotid compression is readily evaluated with carotid duplex interrogation, which locates the carotid bifurcation in its usual upper cervical position and assures that the infrequent atherosclerotic lesion in the proximal cervical segment of the common carotid artery is not present. Brain injury as a result o f thrombotic occlusion of a severe carotid lesion is most unlikely if the collateral ophthalmic systolic pressure is greater than 70 mm Hg. 6 This knowledge is invaluable in predicting the safety o f internal carotid ligation in the management of operatively unapproachable distal internal carotid aneurysms and in assessing the potential consequence of allowing an asymptomatic high-grade carotid lesion to progress to thrombotic occlusion. William Gee,MD
Vascular Laboratory Lehigh Valley Hospital Center Box 689 Allentown, PA 18105
REFERENCES
1. Moneta GL, Taylor DC, Ziesler RE, Klagmers A, Beach K, Strandness DE. &symptomatic high-grade internal carotid artery stenosis: Is stratification according to risk factors or duplex spectral analysis possible? J VAsc SURG 1989;10:475-83. 2. Castaldo JE, Nicholas GG, Gee W, Reed JF. Duplex ultrasound and ocular pneumoplethysmography concordance in detecting severe carotid stenosis. Arch Neurol 1989;46:518-22. 3. Gee W, Mehigan JT, Wylie EJ. Measurement of collateral hemispheric blood pressure by ocular pneumoplethysmography. Am J Surg 1975;130:121-7. 4. Johnston GG, Bernstein EF. Quantification of internal carotid artery stenosis by ocular pneurnoplethysmography: Surg Forum 1975;26:290-1. 5. Eikelboom BC, Vermeulen FEE, Nieuwenhuis EA. Ocular pneumoplethysmography (O.P.G) in the detection and evaluation of obstructive extracranial carotid artery disease. Communications of the twenty-seventh International Congress of the European Chapter of the International Cardiovascular Society. Documentation Medicale Oberval, Lyon 1979;2:193-7. 6. Ehrenfeld WK, Stoney RJ, Wylie EJ. Relation of carotid stump pressure to safety of carotid ligation. Surgery 1983;93:299305.
5. 6. "7. 8.
bosis of ifiofemoral vein. Surg Gynecol Obstet 1986;163: 111-6. Swedenborg J, Hagglof R, Jacobsson H, et al. Results of surgical treatment for iliofemoral venous thrombosis. Br J Surg 1986; 73:871-4. KiUewichLA, Bedford GR, Beach KW, Strandness DE. Spontaneous lysis of deep venous thrombi: rate and outcome. J VAsc SURG 1989;9:89-97. de Araujo Bessa IC. Femoral and iliofemoral thrombectomy to prevent chronic venous insufficiency. J Cardiovasc Surg 1986;27:443-6. Lindner DJ, Edwards JM, Phinney ES, Taylor LM, Porter JM. Long-term hemodynamic and clinical sequelae of lower extremity deep venous thrombosis. J VASCSUgG 1986;4:43642.
Asymptomatic high-grade internal carotid stenosis ,: =d ocular pneumoplethysmography To the Editors:
A recent article in the JOUWNALby Moneta et al. 1 de"scribes the stratification of asymptomatic high-grade internal carotid stenosis by duplex spectral analysis. The principal role ofultrasonographic imaging and spectral analysis in the assessment o f carotid lesions is incontrovertible. A recent report from this institution supports this conclusion. 2 However, this tool is not perfect, and clinically usefi,tl information is provided by ocular pneumoplethysmography (OPG-Gee), especially in the overall evaluation of the "asymptomatic severe carotid stenosis, which implies adequate collateral hemodynamic compensation and embologenic silence. Intracranial hemodynamic compensation is not assured if systemic hypotension is encountered, which is not uncommon during coronary procedures, other arterial re_pairs, and major orthopedic and visceral ablative operations. Success o f any of these procedures complicated by ~ oke as a result of thrombotic occlusion of an asymptomatic high-grade carotid lesion is devastating to all concerned. Any decision to consciously ignore the possibility of such a lesion before the planned procedure has serious ethical and legal implications, not the least of which is ~inforrned consent. The logistics of screening all such candidates with carotid duplex interrogation is prohibitive. The OPG-Gee is a rapid, simple, relatively inexpensive screening device for this purpose. Even when this test is false negative in the presence of an asymptomatic severe carotid lesion, it is true negative in regard to the liemodynamic consequences of this lesion.
Letters to the editor
107
The OPG-Gee was originally designed and developed for use with proximal common carotid compression to noninvasively ascertain the collateral ophthalmic systolic pressure? This assessment compares closely with operative internal carotid systolic pressure measurements, both direct and collateral. 4,s Safety of proximal common carotid compression is readily evaluated with carotid duplex interrogation, which locates the carotid bifurcation in its usual upper cervical position and assures that the infrequent atherosclerotic lesion in the proximal cervical segment of the common carotid artery is not present. Brain injury as a result o f thrombotic occlusion of a severe carotid lesion is most unlikely if the collateral ophthalmic systolic pressure is greater than 70 mm Hg. 6 This knowledge is invaluable in predicting the safety o f internal carotid ligation in the management of operatively unapproachable distal internal carotid aneurysms and in assessing the potential consequence of allowing an asymptomatic high-grade carotid lesion to progress to thrombotic occlusion. William Gee,MD
Vascular Laboratory Lehigh Valley Hospital Center Box 689 Allentown, PA 18105
REFERENCES
1. Moneta GL, Taylor DC, Ziesler RE, Klagmers A, Beach K, Strandness DE. &symptomatic high-grade internal carotid artery stenosis: Is stratification according to risk factors or duplex spectral analysis possible? J VAsc SURG 1989;10:475-83. 2. Castaldo JE, Nicholas GG, Gee W, Reed JF. Duplex ultrasound and ocular pneumoplethysmography concordance in detecting severe carotid stenosis. Arch Neurol 1989;46:518-22. 3. Gee W, Mehigan JT, Wylie EJ. Measurement of collateral hemispheric blood pressure by ocular pneumoplethysmography. Am J Surg 1975;130:121-7. 4. Johnston GG, Bernstein EF. Quantification of internal carotid artery stenosis by ocular pneurnoplethysmography: Surg Forum 1975;26:290-1. 5. Eikelboom BC, Vermeulen FEE, Nieuwenhuis EA. Ocular pneumoplethysmography (O.P.G) in the detection and evaluation of obstructive extracranial carotid artery disease. Communications of the twenty-seventh International Congress of the European Chapter of the International Cardiovascular Society. Documentation Medicale Oberval, Lyon 1979;2:193-7. 6. Ehrenfeld WK, Stoney RJ, Wylie EJ. Relation of carotid stump pressure to safety of carotid ligation. Surgery 1983;93:299305.