- Email: [email protected]
Regional cerebral blood flow (rCBF) and cerebral vasoreactivity in patients with retinal ischaemic symptoms
ABSTRACTS James S. T. Yao, MD, Abstracts
Section Editor
Prevalence of atherosclerotic renal artery stenosis in patients with atherosclerosis elsewhere Olin JW, Melia M, Young JR, Graor RA, Risius BA. Am J Med 1990$X8:46-51. Renal artery stenosis has been reported to occur in 22% to 40% of patients with peripheral vascular disease, but its severity has not been fully characterized. The authors’ objective was to determine the prevalence of unsuspected atherosclerotic renal artery stenosis among patients undergoing arteriography for evaluation of abdominal aortic aneurysm or lower extremity arterial occlusive disease for comparison to that observed among a group of patients with clinically suspected renal artery stenosis. The arteriograms and hospital records of 395 consecutive patients undergoing evaluation for abdominal aortic aneurysm (109), aortic occlusive disease (21), lower extremity occlusive disease (189), and clinically suspected renal artery stenosis (76) from July 1987 to September 1988 at the Cleveland Clinic Foundation were prospectively reviewed. The renal arteries were classified as normal, mildly stenotic (1% to 49%), moderately stenotic (50% to 749/o), severely stenotic (75% to 99%) and occluded. The coincidence of hypertension, diabetes, coronary artery disease, and azotemia were noted, and the data were subjected to statistical analysis. Severe bilateral renal artery stenosis or total occlusion occurred in 6% (7/ 109) of the abdominal aortic aneurysm patients, 14% (3/21) with aortic occlusive disease, 3% (6/89) with lower extremity occlusive disease, and 20% (15/76) with clinically suspected renal artery stenosis. At least one severely stenotic or occluded renal artery was demonstrated in 18% (191109) of patients with abdominal aortic aneurysm, 15 % (3 / 2 1) with aortic occlusive disease, 19% (36/ 189) with lower extremity occlusive disease, and 62% (47/76) with clinically suspected renal artery stenosis. When one renal artery was occluded, a 50% or more contralateral renal artery lesion was observed in 83% (5/6) of abdominal aortic aneurysm patients, 100% (2 /2) with aortic occlusive disease, 33Oh (2/6) with lower extremity occlusive disease, and 67% (12118) with clinically suspected renal artery stenosis. Diabetic patients with abdominal aortic aneurysms, aortic occlusive disease, and clinically suspected renal artery stenosis had a similar prevalence of moderate or greater renal artery stenosis as nondiabetic patients. However, among patients with lower extremity occlusive disease, the prevalence of moderate or worse renal artery stenosis in the diabetic subset was 50% (34/68), whereas it was 33% (40/121) in the nondiabetic subset (p = 0.022). An association between the degree of renal artery stenosis and the presence of hypertension or awtemia was suggested. The authors concluded that patients with abdominal aortic aneurysm, aortic occlusive disease, and lower ex-
tremity occlusive disease have a substantial prevalence of moderate or greater renal artery occlusive disease, which was clinically unsuspected. Among patients with abdominal aortic aneurysms, aortic occlusive disease or clinically suspected renal artery occlusive disease, diabetic patients have a similar prevalence of moderate or worse renal artery occlusive disease to nondiabetic patients. However, among patients with lower extremity occlusive disease, the diabetic subset has a significantly higher prevalence of moderate or greater renal artery stenosis compared to the nondiabetic subset. This information may have therapeutic implications for some patients being considered for vascular reconstruction. Patrick J. O’Hara, MD Cleveland Clinic Foundation
Long saphenous vein saving surgery for varicose veins. A long-term follow-up Hammarsten J, Pedersen P, Cederlund Eur J Vast Surg 1990;4:361-4.
C, Campanello
M.
This randomized, prospective clinical trial evaluates two surgical methods for treatment of saphenous distribution varicosities: group I, terminal saphenous branch ligation, perforator ligation, and standard stripping of the long saphenous vein; group II, terminal branch ligation, ligation of perforators, and ligation of the saphenofemoral junction. Clinically graded excellent (no varicosities-no complaints) or good (varicosities-no complaints) results were obtained in 88% of the group I patients and in 89% of the group II patients. Recurrent varicosities developed in 12% of the group I patients and 11% of the group II patients. Differences between these two groups were statistically insignikmt. Ultrasonic evaluation of the saphenous vein in the group II patients demonstrated patent nonsclerotic and nondilated veins in 16 of 18 patients. The authors conclude that removal of the saphenous vein is of no therapeutic value if all perforators to the deep system are ligated. Ligation of perforators to the deep system and ligation of the saphenofemoral junction preserves a venous conduit that can be used for future arterial reconstructions. William D. Turnipseed, MD University of Wix-onsin-Mad&on
Medical
School
Regional cerebral blood flow (rCBF) and cerebral vasoreactivity in patients with retinal ischaemic symptoms Kerty E, Russell D, Bakke S, Nyberg-Hansen R, Rootwell K. J Neural Neurosurg Psychiat 1989;52:1345-50. Twenty-eight consecutive patients with retinal ischemit symptoms (i.e., amaurosis fiigax or acute monocular 569
570
Journal of VASCULAR SURGERY
Abstracts
visual field defects) were assessed for cerebral vasoreactivity and regional cerebral blood flow (rCBF) This group comprised 17 men and 11 women, with an average age of 55 years (range, 23 to 78 years). Patients with evidence of infarction on cerebral CT’ examination, or history of cerebral transient ischemic attacks or stroke were excluded. Angiography was performed in 15 patients, whereas all 28 underwent pulsed Doppler spectral analysis of the precerebral carotid arteries. Regional cerebral blood flow was measured by use of Xenon 133 inhalation and single photon emission CT scanning, and consisted of a baseline examination followed by another measurement after 1 gm acetazolamide administration. End-expiratory Pcoz also was measured. All values were compared to 25 controls (average age, 41 years), 12 of whom received acetazolamide. Doppler and angiographic examinations demonstrated that 11 (39%) of the 28 patients (average age, 63 years; range, 44 to 77 years) had an atherosclerotic lesion in the precerebral internal carotid artery ipsilateral to symptoms. Mean baseline rCBF values and the response to acetazolamide were significantly lower on the side ipsilateral to symptoms compared with the contralateral side. The sideto-side asymmetry of the response was significantly greater than in the controls. Baseline rCBF values in all regions of interest contralateral to symptoms and the response to aceta&amide in the anterior cerebral artery perfusion territory on this side were also significantly lower than controls. The remaining 17 patients (average age, 50 years; range, 23 to 73 years) had no evidence of carotid occlusive disease. Baseline rCBF values in all regions of interest on both the symptomatic and the contralateral side were significantly lower than those in the control group. However, values for the two sides did not differ significantly, and the acetazolamide response as well as the asymmetry of the response were within normal limits. Mean PCO~ values and the decrease in Pcq after acetazolamide administration did not differ significantly from controls. The results suggest that patients with retinal ischemic symptoms caused by carotid atherosclerosis often have a carotid lesion that is of hemodynamic significance with regard to cerebral perfusion and vasoreactivity even though no symptoms of cerebral ischemia exist. Furthermore, the presence of unilateral or bilateral areas with reduced rCBF may also occur in some patients with normal precerebral carotid arteries. Richard E. Welling, MD Good Samaritan Hospital
Value of the ventilatio+erfusion scan in acute pulmonary embolism: The prospective investigation of pulmonary embolism diagnosis (PIOPED)
investigators.
JAMA
1990;Vol.
263:2753-9.
The PIOPED investigators report on a multicenter study to estimate the sensitivity and specificity of ventilation/perfusion (V/Q) lung scans for the diagnosis of pulmonary embolism (PE). Between January 1985 and September 1986,1493 patients were prospectively studied. Nine hundred thirty-one patients had V/Q scans and 755 pulmonary angiograms; the 176 patients who did not undergo angiography had “insignificant” V/Q scan abnormalities. Thirteen percent (124) of patients had high probability V/Q scans for PE, 73% (676) intermediate or low probability scans, and 14% (131) near normal/normal scans. Among the 755 patients who had pulmonary angiography, 33% (251) had thromboemboli identified, 64% (480) no thromboemboli, and only 3% (24) were uncertain for diagnosis. A comparison between the V/Q scan probability categories with pulmonary angiography in relation to sensitivity and specificity demonstrated that the high probability scan category had 41% sensitivity and 97% specificity; the high or intermediate probability scan category had 82% sensitivity and 52% specificity; and the high, intermediate or low probability scan category had 98% sensitivity and 10% specificity. The PIOPED results settle controversies about the value of lung scans in the diagnosis of PE. A highprobability scan indicates PE, but only a minority of patients have a high-probability scan, and a history of PE decreases the scan’s diagnostic accuracy. A low-probability scan and minimal clinical findings for PE makes the possibility of PE remote. Near normal/normal lung scans make the diagnosis of acute PE unlikely. An indeterminant scan is not helpful in establishing a diagnosis. In conclusion, the V/Q scan combined with clinical assessment permitted a noninvasive diagnosis or exclusion of acute PE in only a minority of patients. David Rosenthal, MD Georgia Baptist Medical
Center
Section Editor
Prevalence of atherosclerotic renal artery stenosis in patients with atherosclerosis elsewhere Olin JW, Melia M, Young JR, Graor RA, Risius BA. Am J Med 1990$X8:46-51. Renal artery stenosis has been reported to occur in 22% to 40% of patients with peripheral vascular disease, but its severity has not been fully characterized. The authors’ objective was to determine the prevalence of unsuspected atherosclerotic renal artery stenosis among patients undergoing arteriography for evaluation of abdominal aortic aneurysm or lower extremity arterial occlusive disease for comparison to that observed among a group of patients with clinically suspected renal artery stenosis. The arteriograms and hospital records of 395 consecutive patients undergoing evaluation for abdominal aortic aneurysm (109), aortic occlusive disease (21), lower extremity occlusive disease (189), and clinically suspected renal artery stenosis (76) from July 1987 to September 1988 at the Cleveland Clinic Foundation were prospectively reviewed. The renal arteries were classified as normal, mildly stenotic (1% to 49%), moderately stenotic (50% to 749/o), severely stenotic (75% to 99%) and occluded. The coincidence of hypertension, diabetes, coronary artery disease, and azotemia were noted, and the data were subjected to statistical analysis. Severe bilateral renal artery stenosis or total occlusion occurred in 6% (7/ 109) of the abdominal aortic aneurysm patients, 14% (3/21) with aortic occlusive disease, 3% (6/89) with lower extremity occlusive disease, and 20% (15/76) with clinically suspected renal artery stenosis. At least one severely stenotic or occluded renal artery was demonstrated in 18% (191109) of patients with abdominal aortic aneurysm, 15 % (3 / 2 1) with aortic occlusive disease, 19% (36/ 189) with lower extremity occlusive disease, and 62% (47/76) with clinically suspected renal artery stenosis. When one renal artery was occluded, a 50% or more contralateral renal artery lesion was observed in 83% (5/6) of abdominal aortic aneurysm patients, 100% (2 /2) with aortic occlusive disease, 33Oh (2/6) with lower extremity occlusive disease, and 67% (12118) with clinically suspected renal artery stenosis. Diabetic patients with abdominal aortic aneurysms, aortic occlusive disease, and clinically suspected renal artery stenosis had a similar prevalence of moderate or greater renal artery stenosis as nondiabetic patients. However, among patients with lower extremity occlusive disease, the prevalence of moderate or worse renal artery stenosis in the diabetic subset was 50% (34/68), whereas it was 33% (40/121) in the nondiabetic subset (p = 0.022). An association between the degree of renal artery stenosis and the presence of hypertension or awtemia was suggested. The authors concluded that patients with abdominal aortic aneurysm, aortic occlusive disease, and lower ex-
tremity occlusive disease have a substantial prevalence of moderate or greater renal artery occlusive disease, which was clinically unsuspected. Among patients with abdominal aortic aneurysms, aortic occlusive disease or clinically suspected renal artery occlusive disease, diabetic patients have a similar prevalence of moderate or worse renal artery occlusive disease to nondiabetic patients. However, among patients with lower extremity occlusive disease, the diabetic subset has a significantly higher prevalence of moderate or greater renal artery stenosis compared to the nondiabetic subset. This information may have therapeutic implications for some patients being considered for vascular reconstruction. Patrick J. O’Hara, MD Cleveland Clinic Foundation
Long saphenous vein saving surgery for varicose veins. A long-term follow-up Hammarsten J, Pedersen P, Cederlund Eur J Vast Surg 1990;4:361-4.
C, Campanello
M.
This randomized, prospective clinical trial evaluates two surgical methods for treatment of saphenous distribution varicosities: group I, terminal saphenous branch ligation, perforator ligation, and standard stripping of the long saphenous vein; group II, terminal branch ligation, ligation of perforators, and ligation of the saphenofemoral junction. Clinically graded excellent (no varicosities-no complaints) or good (varicosities-no complaints) results were obtained in 88% of the group I patients and in 89% of the group II patients. Recurrent varicosities developed in 12% of the group I patients and 11% of the group II patients. Differences between these two groups were statistically insignikmt. Ultrasonic evaluation of the saphenous vein in the group II patients demonstrated patent nonsclerotic and nondilated veins in 16 of 18 patients. The authors conclude that removal of the saphenous vein is of no therapeutic value if all perforators to the deep system are ligated. Ligation of perforators to the deep system and ligation of the saphenofemoral junction preserves a venous conduit that can be used for future arterial reconstructions. William D. Turnipseed, MD University of Wix-onsin-Mad&on
Medical
School
Regional cerebral blood flow (rCBF) and cerebral vasoreactivity in patients with retinal ischaemic symptoms Kerty E, Russell D, Bakke S, Nyberg-Hansen R, Rootwell K. J Neural Neurosurg Psychiat 1989;52:1345-50. Twenty-eight consecutive patients with retinal ischemit symptoms (i.e., amaurosis fiigax or acute monocular 569
570
Journal of VASCULAR SURGERY
Abstracts
visual field defects) were assessed for cerebral vasoreactivity and regional cerebral blood flow (rCBF) This group comprised 17 men and 11 women, with an average age of 55 years (range, 23 to 78 years). Patients with evidence of infarction on cerebral CT’ examination, or history of cerebral transient ischemic attacks or stroke were excluded. Angiography was performed in 15 patients, whereas all 28 underwent pulsed Doppler spectral analysis of the precerebral carotid arteries. Regional cerebral blood flow was measured by use of Xenon 133 inhalation and single photon emission CT scanning, and consisted of a baseline examination followed by another measurement after 1 gm acetazolamide administration. End-expiratory Pcoz also was measured. All values were compared to 25 controls (average age, 41 years), 12 of whom received acetazolamide. Doppler and angiographic examinations demonstrated that 11 (39%) of the 28 patients (average age, 63 years; range, 44 to 77 years) had an atherosclerotic lesion in the precerebral internal carotid artery ipsilateral to symptoms. Mean baseline rCBF values and the response to acetazolamide were significantly lower on the side ipsilateral to symptoms compared with the contralateral side. The sideto-side asymmetry of the response was significantly greater than in the controls. Baseline rCBF values in all regions of interest contralateral to symptoms and the response to aceta&amide in the anterior cerebral artery perfusion territory on this side were also significantly lower than controls. The remaining 17 patients (average age, 50 years; range, 23 to 73 years) had no evidence of carotid occlusive disease. Baseline rCBF values in all regions of interest on both the symptomatic and the contralateral side were significantly lower than those in the control group. However, values for the two sides did not differ significantly, and the acetazolamide response as well as the asymmetry of the response were within normal limits. Mean PCO~ values and the decrease in Pcq after acetazolamide administration did not differ significantly from controls. The results suggest that patients with retinal ischemic symptoms caused by carotid atherosclerosis often have a carotid lesion that is of hemodynamic significance with regard to cerebral perfusion and vasoreactivity even though no symptoms of cerebral ischemia exist. Furthermore, the presence of unilateral or bilateral areas with reduced rCBF may also occur in some patients with normal precerebral carotid arteries. Richard E. Welling, MD Good Samaritan Hospital
Value of the ventilatio+erfusion scan in acute pulmonary embolism: The prospective investigation of pulmonary embolism diagnosis (PIOPED)
investigators.
JAMA
1990;Vol.
263:2753-9.
The PIOPED investigators report on a multicenter study to estimate the sensitivity and specificity of ventilation/perfusion (V/Q) lung scans for the diagnosis of pulmonary embolism (PE). Between January 1985 and September 1986,1493 patients were prospectively studied. Nine hundred thirty-one patients had V/Q scans and 755 pulmonary angiograms; the 176 patients who did not undergo angiography had “insignificant” V/Q scan abnormalities. Thirteen percent (124) of patients had high probability V/Q scans for PE, 73% (676) intermediate or low probability scans, and 14% (131) near normal/normal scans. Among the 755 patients who had pulmonary angiography, 33% (251) had thromboemboli identified, 64% (480) no thromboemboli, and only 3% (24) were uncertain for diagnosis. A comparison between the V/Q scan probability categories with pulmonary angiography in relation to sensitivity and specificity demonstrated that the high probability scan category had 41% sensitivity and 97% specificity; the high or intermediate probability scan category had 82% sensitivity and 52% specificity; and the high, intermediate or low probability scan category had 98% sensitivity and 10% specificity. The PIOPED results settle controversies about the value of lung scans in the diagnosis of PE. A highprobability scan indicates PE, but only a minority of patients have a high-probability scan, and a history of PE decreases the scan’s diagnostic accuracy. A low-probability scan and minimal clinical findings for PE makes the possibility of PE remote. Near normal/normal lung scans make the diagnosis of acute PE unlikely. An indeterminant scan is not helpful in establishing a diagnosis. In conclusion, the V/Q scan combined with clinical assessment permitted a noninvasive diagnosis or exclusion of acute PE in only a minority of patients. David Rosenthal, MD Georgia Baptist Medical
Center