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Complications and validity of pulmonary angiography in acute pulmonary embolism
JOURNAL OF VASCULAR Volume 18, Number 2
SURGERY
in the control group and the group with PVD, differences were seen only in total cholesterol and cholesterol and triglyceride content of the IDL fraction. Comparison between those with moderate and severe disease demonstrated an increasein IDL cholesterol and triglyceride and a decreasein HDL cholesterol with more severe disease. There was no difference in the proportion of apolipoprotein E phenotypes. The authors conclude that IDL abnormalities play an important role in development and severity of peripheral vascular disease. Although this is an interesting study, the data do not support the conclusion. Although, the statistical analysis used is adequate for comparing independent variables, its appropriateness for the complex analysis of interrelated variables such as lipid indexes is questionable. Furthermore, although this type of study can demonstrate an association, no causal relationship can or should be assumed. This type of study can only suggest that serum lipid levels are a factor in the development of PVD. It does not provide sufficient evidence to implement therapy directed toward changing IDL content. These decisions must await future studies that correlate progression, rather than presence, of diseasewith serial determinations of lipid indexes. B. Timothy Baxter, AJLI Universiy of Nebraska
Simultaneous and peripheral
revascularization vascular ischemia
for
critical
coronary
Carrel T, Niederhauser U, PasicM, Gallino A, von Segesser L, Turina M. Ann Thorac Surg 1991;52:805-9. This report summarizes an experience with 32 patients who underwent simultaneous coronary artery bypass grafting and a peripheral vascular operation for occlusive diseaseunder the same anesthetic. The authors state that such combined operation was occasioned by critical and severely symptomatic disease in both vascular territories. With the exception of three femoral popliteal bypassgrafts, the vascular surgery procedures involved operation on the aortoiliac segments. Certainly the practice of vascular surgery at the University Hospital in Zurich, Switzerland, differs significantly from that performed in this country; 19 of the 32 vascular procedures were aortoiliac or iliofemoral endarterectomies, whereas there were but 10 aortoiliac or aortofemoral bypass grafts for occlusive disease. Furthermore, sevenof the 32 operations performed for peripheral occlusive diseasewere in patients with claudication alone. It is clear that the authors have a commitment to the concept of combined operations. Although this report considers 32 combined operations carried out where the vascular problem was peripheral occlusive disease, the authors mention that this is from a pool of 135 simultaneous coronary and vascularoperations performed over the interval 1978 to 1990. Presumably the balance of these procedures represents simultaneous coronary and carotid artery or abdominal aortic aneurysm operations. Indeed, there is an interesting graph in the text of the article indicating that in 1990, 8% of all coronary artery bypasses
performed at their institution were combined with a simultaneous vascular surgery procedure. The technical aspectsof their operations are interesting in that a single surgical team performed both the coronary and vascular operations. The statement is made in their article that an expeditious operation is part of the overall treatment strategy. Indeed, operative time for such involved procedures was a very admirable mean of 3.75 hours! Early mortality rate was 3.1% and not significantly different from the mortality rate associated with isolated coronary bypass in patients with comparable patterns of coronary disease.Repeat operation for early vascular graft failure was required in a single patient. Long-term survival rate was nearly 90% in this small group of patients, and the authors make the point that this is similar to the survival rate after isolated coronary artery bypass grafting in patients operated on at their hospital but considerably superior to the late survival in patients undergoing isolated repair of abdominal aortic aneurysm or peripheral vascular operation for occlusivedisease.Thus an aggressiveposture toward coronary artery disease is advocated to increase long-term survival in patients requiring peripheral vascular operation. The authors have demonstrated in a small number of patients that acceptable morbidity and long-term survival rates can be achieved by simultaneous performance of coronary and peripheral vascular operations. They conclude that this type of combined approach is likely to be used with increasing frequency in the future. I disagree with this conclusion. Although we embrace the concept of combined operation for patients with simultaneous carotid artery and coronary artery disease,coronary bypasshas not been combined with aortoiliac reconstructive surgery in our unit. Despite the fact that the authors have demonstrated the safety of a combined approach in their hands, this begs the issue of whether such a combined operation is necessary or desirable. In most patients with truly pressing indications for treatment in both vascular territories, our preference is initial coronary revascularization, which can be followed within days, if necessary, by aortoiliac reconstruction. Alternatively, in those circumstances where peripheral revascularization is the clear priority, a variety of low-risk treatment options, familiar to all vascular surgeons, can be applied. Richard P. Cambriu, ML2 Massacbssem General Hospital Boston, Mass.
Complications and validity of pulmonary in acute pulmonary embolism
angiography
Stein PD, Athanasoulis C, Alvavi A, et al. Circulation 1992;85:462-8. This is a sequel to the initial publication from the Prospective Investigation of Pulmonary Embolism Diagnosis study that reported on the value of ventilationperfusion scans with pooled data collected from nine centers. The purpose of this investigation was to use the
JOURNAL
338
OF VASCULAR
Abstracts
Prospective Investigation of Pulmonary Embolism Diagnosis data to evaluate the risks and diagnostic validity of pulmonary angiography. There were two arms to the study: the first consisted of 762 patients who agreed to angiography if pulmonary ventilation-perfusion scan results were abnormal. The second contained 349 patients in whom the decision to perform pulmonary angiography was based on clinical judgment alter ventilation-perfusion scanning was performed by the attending physician. Thus a total of 1111 patients were included. Pulmonary angiography was performed according to a protocol that called for a femoral Seldinger technique with a pigtail catheter. The volume and rate of injection of contrast could be reduced in the presence of pulmonary hypertension at the discretion of the radiologist. Angiograms were read, in conjunction with the ventilation-perfusion scan, by a pair of angiographers not from the originating institution. Disagreements on the interpretation were resolved by a second pair of angiographers randomly selected from participating hospitals. Five deaths (O.SOh)were attributed to the procedure, because they occurred within a few days of angiography. Major, nonfatal complications occurred in nine (1%) patients and included three who required dialysis and four who had respiratory distress necessitating temporary mechanical ventilation. Minor complications occurred in 60 patients; transient renal failure was the most common, affecting 10. Most of the patients who died or had a major complication had severe associated cardiac or pulmonary insufficiency, which may have been contributing factors. The incidence of complications was not related to age, sex, presence or absence of pulmonary embolus, volume of contrast material, or to the mean pulmonary artery pressure. Pulmonary emboli were diagnosed on 383 (35%) of angiograms, 3% of which were nondiagnostic and 1% were incomplete. In four of the 681 negative angiography results the reading was reversed by the finding of a pulmonary embolus at autopsy. The low incidence of major morbidity and mortality for an invasive procedure, which is frequently performed on ill patients, is striking. Of particular interest is the absenceof a single case of myocardial perforation. Why were the results from this study so good? Unfortunately the authors provide very little data to enable the reader to analyze the reasons for their success.Obviously, the experience of the participating institutions and principal investigators was an important determinant. However, it is also possible that simply following a well-designed protocol that required the use of a pigtail catheter and avoided contrast injection into the main pulmonary artery may have been an important factor that contributed to their enviable results. Bmce
S. Cut&y, MD Massachusetts Wurcester, Mass.
Universityof
Peripheral
vascular
Medical
injuries
School
in children
Eren N, Ozgen G, Ener B, Solak H, Furtun K. J Pediatr Surg 1991;26:1164-8. This article reviews the diagnosis and treatment of peripheral vascular injuries in 91 children (3 to 14 years) at a
SURGERY August 1993
university hospital in Turkey from 1978 to 1988. Gunshot wounds and stab wounds accounted for nearly 75% of the vascular injuries in this series, and iatrogenic injury was identified in only two cases.Vascular injuries were evenly divided between the upper and lower extremities and were much more common in boys than girls. The brachial artery was the most commonly injured artery. The time to arrival in the hospital was longer than 8 hours in all patients in the seriesand greater than 18 hours in nearly one quarter. The diagnosis of major vascular injury was based solely on physical signs in most patients. Pulseswere absent in 91% of injuries, and there was an obvious wound with arterial hemorrhage in more than 50% of injuries. Preoperative arteriography was used in only 16.5% of patients. Treatment consisted of primary repair with end-to-end anastomosis (65%), saphenous vein graft (23%), lateral repair (8%), and ligation (4%). Simultaneous venous repair was undertaken in 39 cases.Revascularization was successfulin 77 (82%) of 94 cases.Postoperative infection developed in 8%, and thrombosis occurred in 10%. Four amputations were required (5%). This seriesof vascularinjuries in children is unique for several reasons. First, unlike most contemporary series from North America in which iatrogenic injuries predominate, gunshot wounds and stab wounds were responsible for three quarters of injuries in this article. It is known that the risk of iatrogenic vascular injury is inversely related to the age of the patient, and most iatrogenic injuries occur as a result of cardiac catheterization in children younger than 2 years. Second, the time to definitive care was substantially longer (10.8 hours) in this seriesthan is currently available in modern trauma systems, yet despite these delays the authors have achieved a high degree of success.Third, the successof the authors in achieving limb salvage in most patients seems to be due to an aggressive policy toward vascular injuries in children and to the considerable diagnostic acumen and technical skill of the surgeons responsible. The authors have emphasized the importance of meticulous operative technique, debridement of all devitalized tissue, the use of interrupted sutures to allow for continued vasculargrowth, and covering the reconstruction with vascular tissue to decreasethe risk of infection. This article fails to answer severalimportant questions regarding peripheral vascular injuries in children. The diagnosis of injuries was based almost exclusively on physical signs, and the role of arteriography is unclear. The long-term patency rates of arterial and venous repairs are not stated clearly. Although venous repair was attempted in most caseswhere technically feasible, there is no evidence that ligation would not be equally effective. The authors do not state the rate of primary amputation without attempts at vascular repair or what guidelines to follow. The effect of failed reconstruction on eventual limb length discrepancies is not discussed. In summary, this article reviews the treatment of a large number of vascular injuries in children at a single hospital. The primary message is that vascular reconstruction in children should be undertaken if technically feasible. John F. Eidt, MD Univewity of Arkansas Little Rock, Ark.
jiw Medical
Sciences
SURGERY
in the control group and the group with PVD, differences were seen only in total cholesterol and cholesterol and triglyceride content of the IDL fraction. Comparison between those with moderate and severe disease demonstrated an increasein IDL cholesterol and triglyceride and a decreasein HDL cholesterol with more severe disease. There was no difference in the proportion of apolipoprotein E phenotypes. The authors conclude that IDL abnormalities play an important role in development and severity of peripheral vascular disease. Although this is an interesting study, the data do not support the conclusion. Although, the statistical analysis used is adequate for comparing independent variables, its appropriateness for the complex analysis of interrelated variables such as lipid indexes is questionable. Furthermore, although this type of study can demonstrate an association, no causal relationship can or should be assumed. This type of study can only suggest that serum lipid levels are a factor in the development of PVD. It does not provide sufficient evidence to implement therapy directed toward changing IDL content. These decisions must await future studies that correlate progression, rather than presence, of diseasewith serial determinations of lipid indexes. B. Timothy Baxter, AJLI Universiy of Nebraska
Simultaneous and peripheral
revascularization vascular ischemia
for
critical
coronary
Carrel T, Niederhauser U, PasicM, Gallino A, von Segesser L, Turina M. Ann Thorac Surg 1991;52:805-9. This report summarizes an experience with 32 patients who underwent simultaneous coronary artery bypass grafting and a peripheral vascular operation for occlusive diseaseunder the same anesthetic. The authors state that such combined operation was occasioned by critical and severely symptomatic disease in both vascular territories. With the exception of three femoral popliteal bypassgrafts, the vascular surgery procedures involved operation on the aortoiliac segments. Certainly the practice of vascular surgery at the University Hospital in Zurich, Switzerland, differs significantly from that performed in this country; 19 of the 32 vascular procedures were aortoiliac or iliofemoral endarterectomies, whereas there were but 10 aortoiliac or aortofemoral bypass grafts for occlusive disease. Furthermore, sevenof the 32 operations performed for peripheral occlusive diseasewere in patients with claudication alone. It is clear that the authors have a commitment to the concept of combined operations. Although this report considers 32 combined operations carried out where the vascular problem was peripheral occlusive disease, the authors mention that this is from a pool of 135 simultaneous coronary and vascularoperations performed over the interval 1978 to 1990. Presumably the balance of these procedures represents simultaneous coronary and carotid artery or abdominal aortic aneurysm operations. Indeed, there is an interesting graph in the text of the article indicating that in 1990, 8% of all coronary artery bypasses
performed at their institution were combined with a simultaneous vascular surgery procedure. The technical aspectsof their operations are interesting in that a single surgical team performed both the coronary and vascular operations. The statement is made in their article that an expeditious operation is part of the overall treatment strategy. Indeed, operative time for such involved procedures was a very admirable mean of 3.75 hours! Early mortality rate was 3.1% and not significantly different from the mortality rate associated with isolated coronary bypass in patients with comparable patterns of coronary disease.Repeat operation for early vascular graft failure was required in a single patient. Long-term survival rate was nearly 90% in this small group of patients, and the authors make the point that this is similar to the survival rate after isolated coronary artery bypass grafting in patients operated on at their hospital but considerably superior to the late survival in patients undergoing isolated repair of abdominal aortic aneurysm or peripheral vascular operation for occlusivedisease.Thus an aggressiveposture toward coronary artery disease is advocated to increase long-term survival in patients requiring peripheral vascular operation. The authors have demonstrated in a small number of patients that acceptable morbidity and long-term survival rates can be achieved by simultaneous performance of coronary and peripheral vascular operations. They conclude that this type of combined approach is likely to be used with increasing frequency in the future. I disagree with this conclusion. Although we embrace the concept of combined operation for patients with simultaneous carotid artery and coronary artery disease,coronary bypasshas not been combined with aortoiliac reconstructive surgery in our unit. Despite the fact that the authors have demonstrated the safety of a combined approach in their hands, this begs the issue of whether such a combined operation is necessary or desirable. In most patients with truly pressing indications for treatment in both vascular territories, our preference is initial coronary revascularization, which can be followed within days, if necessary, by aortoiliac reconstruction. Alternatively, in those circumstances where peripheral revascularization is the clear priority, a variety of low-risk treatment options, familiar to all vascular surgeons, can be applied. Richard P. Cambriu, ML2 Massacbssem General Hospital Boston, Mass.
Complications and validity of pulmonary in acute pulmonary embolism
angiography
Stein PD, Athanasoulis C, Alvavi A, et al. Circulation 1992;85:462-8. This is a sequel to the initial publication from the Prospective Investigation of Pulmonary Embolism Diagnosis study that reported on the value of ventilationperfusion scans with pooled data collected from nine centers. The purpose of this investigation was to use the
JOURNAL
338
OF VASCULAR
Abstracts
Prospective Investigation of Pulmonary Embolism Diagnosis data to evaluate the risks and diagnostic validity of pulmonary angiography. There were two arms to the study: the first consisted of 762 patients who agreed to angiography if pulmonary ventilation-perfusion scan results were abnormal. The second contained 349 patients in whom the decision to perform pulmonary angiography was based on clinical judgment alter ventilation-perfusion scanning was performed by the attending physician. Thus a total of 1111 patients were included. Pulmonary angiography was performed according to a protocol that called for a femoral Seldinger technique with a pigtail catheter. The volume and rate of injection of contrast could be reduced in the presence of pulmonary hypertension at the discretion of the radiologist. Angiograms were read, in conjunction with the ventilation-perfusion scan, by a pair of angiographers not from the originating institution. Disagreements on the interpretation were resolved by a second pair of angiographers randomly selected from participating hospitals. Five deaths (O.SOh)were attributed to the procedure, because they occurred within a few days of angiography. Major, nonfatal complications occurred in nine (1%) patients and included three who required dialysis and four who had respiratory distress necessitating temporary mechanical ventilation. Minor complications occurred in 60 patients; transient renal failure was the most common, affecting 10. Most of the patients who died or had a major complication had severe associated cardiac or pulmonary insufficiency, which may have been contributing factors. The incidence of complications was not related to age, sex, presence or absence of pulmonary embolus, volume of contrast material, or to the mean pulmonary artery pressure. Pulmonary emboli were diagnosed on 383 (35%) of angiograms, 3% of which were nondiagnostic and 1% were incomplete. In four of the 681 negative angiography results the reading was reversed by the finding of a pulmonary embolus at autopsy. The low incidence of major morbidity and mortality for an invasive procedure, which is frequently performed on ill patients, is striking. Of particular interest is the absenceof a single case of myocardial perforation. Why were the results from this study so good? Unfortunately the authors provide very little data to enable the reader to analyze the reasons for their success.Obviously, the experience of the participating institutions and principal investigators was an important determinant. However, it is also possible that simply following a well-designed protocol that required the use of a pigtail catheter and avoided contrast injection into the main pulmonary artery may have been an important factor that contributed to their enviable results. Bmce
S. Cut&y, MD Massachusetts Wurcester, Mass.
Universityof
Peripheral
vascular
Medical
injuries
School
in children
Eren N, Ozgen G, Ener B, Solak H, Furtun K. J Pediatr Surg 1991;26:1164-8. This article reviews the diagnosis and treatment of peripheral vascular injuries in 91 children (3 to 14 years) at a
SURGERY August 1993
university hospital in Turkey from 1978 to 1988. Gunshot wounds and stab wounds accounted for nearly 75% of the vascular injuries in this series, and iatrogenic injury was identified in only two cases.Vascular injuries were evenly divided between the upper and lower extremities and were much more common in boys than girls. The brachial artery was the most commonly injured artery. The time to arrival in the hospital was longer than 8 hours in all patients in the seriesand greater than 18 hours in nearly one quarter. The diagnosis of major vascular injury was based solely on physical signs in most patients. Pulseswere absent in 91% of injuries, and there was an obvious wound with arterial hemorrhage in more than 50% of injuries. Preoperative arteriography was used in only 16.5% of patients. Treatment consisted of primary repair with end-to-end anastomosis (65%), saphenous vein graft (23%), lateral repair (8%), and ligation (4%). Simultaneous venous repair was undertaken in 39 cases.Revascularization was successfulin 77 (82%) of 94 cases.Postoperative infection developed in 8%, and thrombosis occurred in 10%. Four amputations were required (5%). This seriesof vascularinjuries in children is unique for several reasons. First, unlike most contemporary series from North America in which iatrogenic injuries predominate, gunshot wounds and stab wounds were responsible for three quarters of injuries in this article. It is known that the risk of iatrogenic vascular injury is inversely related to the age of the patient, and most iatrogenic injuries occur as a result of cardiac catheterization in children younger than 2 years. Second, the time to definitive care was substantially longer (10.8 hours) in this seriesthan is currently available in modern trauma systems, yet despite these delays the authors have achieved a high degree of success.Third, the successof the authors in achieving limb salvage in most patients seems to be due to an aggressive policy toward vascular injuries in children and to the considerable diagnostic acumen and technical skill of the surgeons responsible. The authors have emphasized the importance of meticulous operative technique, debridement of all devitalized tissue, the use of interrupted sutures to allow for continued vasculargrowth, and covering the reconstruction with vascular tissue to decreasethe risk of infection. This article fails to answer severalimportant questions regarding peripheral vascular injuries in children. The diagnosis of injuries was based almost exclusively on physical signs, and the role of arteriography is unclear. The long-term patency rates of arterial and venous repairs are not stated clearly. Although venous repair was attempted in most caseswhere technically feasible, there is no evidence that ligation would not be equally effective. The authors do not state the rate of primary amputation without attempts at vascular repair or what guidelines to follow. The effect of failed reconstruction on eventual limb length discrepancies is not discussed. In summary, this article reviews the treatment of a large number of vascular injuries in children at a single hospital. The primary message is that vascular reconstruction in children should be undertaken if technically feasible. John F. Eidt, MD Univewity of Arkansas Little Rock, Ark.
jiw Medical
Sciences