Andris Kazmers

Ruptured abdominal aortic aneurysm: the Harborview experience.

During the last decade (1980 to 1989) 186 patients with ruptured abdominal aortic aneurysm were admitted to a single urban hospital. Ninety-six percent of these patients had a prehospital systolic blood pressure less than 90 mm Hg. Management included paramedic field resuscitation and transport, an emergency department diagnostic protocol completed in an average of 12 minutes, rapid transport to a dedicated emergency operating room, aneurysmorrhaphy by general surgery chief residents under the supervision of specialist vascular surgeons, and skilled postoperative intensive care unit care. Nevertheless, 130 (70%) patients died in the first 30 postoperative days--3% in the emergency department, 13% in the operating room, 51% in the intensive care unit, and 3% on the ward or at home. Certain features--age greater than 80 years, female gender, persistent preoperative hypotension despite aggressive crystalloid and blood replacement, admission hematocrit less than 25, transfusion requirements exceeding 15 units--were associated with a greater than 90% likelihood of death. No patient with preoperative cardiac arrest survived more than 24 hours. From this experience we conclude that, although optimal prehospital, emergency department, operating room, and postoperative care can improve the outcome of patients with ruptured abdominal aortic aneurysms in shock, most such patients will die. Certain clinical features predict such excessive mortality rates after ruptured abdominal aortic aneurysms that withholding operation may be reasonable. Screening of patients at high risk for abdominal aortic aneurysm, followed by elective aneurysmorrhaphy, is clearly indicated.

Duplex ultrasound scanning in the diagnosis of renal artery stenosis: A prospective evaluation

Since ultrasonic energy can be used to interrogate vessels at great depth, it is only natural that it should be applied to deeply placed arteries in the abdomen. Early studies suggested that high-grade stenoses of the renal artery could be detected by this approach as long as the peak systolic velocity in the renal artery was normalized by that measured in the abdominal aorta. A retrospective study comparing the peak velocity in the renal artery to that from the adjacent abdominal aorta (the renal aortic ratio) showed that if this value exceeded 3.5, it is likely to be associated with a greater than 60% diameter-reducing stenosis. To test this hypothesis, we used duplex scanning to prospectively evaluate 58 renal arteries in 29 patients in whom arteriograms were available. There were 39 renal arteries with 0% to 59% stenosis, 14 with 60% to 99% stenosis, and five occlusions by angiography. Renal duplex scanning accurately diagnosed 38 of 39, 11 of 14, and four of five of these, respectively, giving a sensitivity of 84%, a specificity of 97%, and a positive predictive value of 94% for the detection of a greater than 60% diameter-reducing stenosis. The overall agreement with angiography was 93%. These data show that renal duplex scanning can be used to diagnose renal artery stenosis in patients with hypertension or renal dysfunction, thus providing a rational basis for the selection of patients for angiography.

Effects of Autonomic Neuropathy on Coronary Blood Flow in Patients With Diabetes Mellitus

BACKGROUNDnC ardiac sympathetic signals play an important role in the regulation of myocardial perfusion. We hypothesized that sympathetically mediated myocardial blood flow would be impaired in diabetics with autonomic neuropathy.nnnMETHODS AND RESULTSnWe studied 28 diabetics (43+/-7 years old) and 11 age-matched healthy volunteers. PET was used to delineate cardiac sympathetic innervation with [(11)C]hydroxyephedrine ([(11)C]HED) and to measure myocardial blood flow at rest, during hyperemia, and in response to sympathetic stimulation by cold pressor testing. The response to cardiac autonomic reflex tests was also evaluated. Using ultrasonography, we also measured brachial artery reactivity during reactive hyperemia (endothelium-dependent dilation) and after sublingual nitroglycerin (endothelium-independent dilation). Based on [(11)C]HED PET, 13 of 28 diabetics had sympathetic-nerve dysfunction (SND). Basal flow was regionally homogeneous and similar in the diabetic and normal subjects. During hyperemia, the increase in flow was greater in the normal subjects (284+/-88%) than in the diabetics with SND (187+/-80%, P=0.084) and without SND (177+/-72%, P=0.028). However, the increase in flow in response to cold was lower in the diabetics with SND (14+/-10%) than in those without SND (31+/-12%) (P=0.015) and the normal subjects (48+/-24%) (P<0.001). The flow response to cold was related to the myocardial uptake of [(11)C]HED (P<0.001). Flow-mediated brachial artery dilation was impaired in the diabetics compared with the normal subjects, but it was similar in the diabetics with and without SND.nnnCONCLUSIONSnDiabetic autonomic neuropathy is associated with an impaired vasodilator response of coronary resistance vessels to increased sympathetic stimulation, which is related to the degree of SND.

Noninvasive diagnosis of renal artery stenosis by ultrasonic duplex scanning.

We retrospectively studied the results of duplex scanning for evaluation of renal artery disease in 158 patients. Satisfactory examinations were achieved in 144 patients (90%). Arteriograms were available for 43 renal arteries. We used the ratio of the peak velocities in the renal artery and the aorta (RAR) to separate nonstenotic arteries (less than 60% diameter reduction) from stenotic arteries (greater than 60% diameter reduction). With an RAR of greater than 3.5 to indicate stenotic lesions, duplex scanning had a sensitivity of 91% (20 of 22 diseased arteries correctly identified) and specificity of 95% (20 of 21 normal or insignificantly diseased arteries correctly identified). One of four occluded arteries was incorrectly interpreted as patent because of misidentification of a collateral vessel. Prospective studies will be necessary to validate this test and establish other criteria for a more detailed classification of renal artery stenosis. The ratio of the end-diastolic to peak systolic velocities in the renal artery (EDR) tended to decrease with increasing serum creatinine levels, presumably because renal vascular resistance increases with end-stage parenchymal disease. EDR may prove useful in the detection of advanced parenchymal disease before renal artery revascularization is attempted.

Vascular function and carotid intimal-medial thickness in children with insulin-dependent diabetes mellitus

OBJECTIVESnThe objective of this study was to evaluate endothelium-dependent vasodilation and carotid intimal-medial thickness (IMT) in children with insulin-dependent diabetes mellitus.nnnBACKGROUNDnDiabetes mellitus is an established risk factor for atherosclerosis. Vascular complications of diabetes are not clinically evident in diabetic children. However, preclinical atherosclerosis is more common in young subjects exposed to cardiovascular risk factors. Endothelial function and carotid IMT, known to be abnormal in preclinical atherosclerosis, have not been studied concurrently in a pediatric population exposed to a risk factor for atherosclerosis.nnnMETHODSnWe studied 31 diabetic teenagers (age 15.0 +/- 2.4 years; duration of diabetes 6.8 +/- 3.9 years) and 35 age-matched healthy children (age 15.7 +/- 2.7 years). Using high-resolution vascular ultrasound, we compared carotid IMT and brachial artery responses to reactive hyperemia (endothelium-dependent vasodilation) and to sublingual nitroglycerin (endothelium-independent vasodilation).nnnRESULTSnThere was no difference in baseline brachial artery diameter between the two groups. Endothelium-dependent vasodilation was significantly lower in diabetic children compared with healthy children (4.2 +/- 3.8% vs. 8.2 +/- 4.2%, p < 0.001). There was no difference in endothelium-independent vasodilation (17 +/- 6% vs. 18 +/- 6%, p = NS) or mean carotid IMT between the groups (0.33 +/- 0.05 vs. 0.32 +/- 0.08 mm, p = NS). Endothelium-dependent brachial vasodilation correlated with blood glucose levels (r = 0.58, p = 0.001) and was weakly and inversely related to the duration of diabetes (r = -0.4, p = 0.02), total cholesterol, and low-density lipoprotein cholesterol levels.nnnCONCLUSIONSnEndothelial function is impaired in children with diabetes mellitus within the first decade of its onset and precedes an increase in carotid IMT. The relative timing of these events is important in the evaluation of strategies to prevent progression of atherosclerosis and other vascular complications in this patient population.

Abdominal aortic aneurysm repair in Veterans Affairs medical centers

PURPOSEnThis study was performed to define outcomes after abdominal aortic aneurysm (AAA) repair in Veterans Affairs (VA) medical centers during fiscal years 1991 through 1993.nnnMETHODSnWith VA patient treatment file data, patients were selected from diagnosis-related groups 110 and 111 and were then classified in a patient management category. In the categories of repair of nonruptured and ruptured AAA, mortality and postoperative complication rates were defined for patients who underwent AAA repair in VA medical centers during the 3-year study period.nnnRESULTSnHospital mortality rates were 4.86% (166 of 3419) after repair of nonruptured AAA and 47.0% (126 of 268) after repair of ruptured AAA (p<0.001). Of 292 deaths after AAA repair, 136 (43.2%) followed repair of ruptured AAA, even though ruptured AAA comprised only 7.3% of total AAA surgical volume. AAA repairs were performed at 116 VA medical centers, with 31.8+/-23.1 (range, 1 to 140) procedures performed at each center. Although many lower-volume centers had excellent results, centers that performed >or=32 AAA repairs tended to have lower in-hospital mortality rates after repair of nonruptured AAA than those that performed <or=31 procedures (4.2%+/-3.5% compared with 6.7%+/-7.8%;p<0.05). Poisson regression analysis revealed an inverse relationship between the volume of AAA repairs and individual hospital mortality (p=0.001) and a direct relationship between illness severity and hospital mortality (p=0.008). The proportion of ruptured AAAs treated in a hospital was also directly related to individual hospital mortality rates (p<0.005). Postoperative complications were associated with an increased hospital mortality rate (11.7% with complication compared with 6.5% without; p<0.0001) and length of stay (23.6+/-17.1 days compared with 18.0+/-12.4 days; p<0.0001). In a logistic regression model, increased mortality rates after AAA repair were associated with hospital type (adjusted odds ratio [OR]=0.6), increasing age (OR=1.1), patient management category severity score (OR=2.2), hemorrhage (OR=2.3), myocardial infarction (OR=2.6), disseminated intravascular coagulation (OR=4.7), AAA rupture (OR=6.0), postoperative shock (OR=10.7), cardiopulmonary arrest (OR=15.4), central nervous system complications (OR=16.0) and urologic complications (OR=2.4).nnnCONCLUSIONSnMortality rates after AAA repair in VA hospitals were comparable with those previously reported in other large series. Outcomes for veterans with AAA may improve by referring patients eligible for elective repair to VA medical centers with a greater operative volume or to lower-volume centers that have had excellent results.

Operative versus nonoperative management of asymptomatic high-grade internal carotid artery stenosis: Improved results with endarterectomy

In a 4-year period, 129 asymptomatic high-grade (80-99%) internal carotid artery stenoses were identified in 115 patients. Because we previously demonstrated a strong relation between degree of carotid stenosis and subsequent development of ipsilateral related events (stroke, transient ischemic attack, and carotid occlusion), we changed our previous policy and began to offer carotid endarterectomy to good surgical risk patients referred to us with asymptomatic high-grade carotid stenosis. A total of 56 carotid endarterectomies were performed while 73 lesions were followed nonoperatively. Operated and nonoperated groups were similar with regard to age, prevalence of hypertension, cardiac disease, diabetes, and aspirin use. Life table analysis to 24 months revealed a higher rate of stroke (19 vs. 4%, p = 0.08), transient focal neurologic deficits (28 vs. 5%, p = 0.008), and carotid occlusion (29 vs. 0%, p = 0.003) in the nonoperated group. Eight of the 9 strokes in the nonoperated group occurred within 9 months of diagnosis of the high-grade lesion; none were preceded by a transient ischemic attack. There was 1 perioperative stroke (1.8%) but no in-hospital operative deaths and no difference in the late death rates of the two groups. This suggests that the preservation of neurologic status in patients with asymptomatic high-grade internal carotid artery stenosis can be improved by carotid endarterectomy.

Cervical reconstruction of the supra-aortic trunks: A 16-year experience

PURPOSEnThe purpose of this study was to review 182 consecutive cervical reconstructions of supra-aortic trunks, which were performed over a 16-year period.nnnMETHODSnA total of 182 innominate, common carotid, or subclavian arteries were reconstructed with a cervical approach in 173 patients aged 23 days to 83 years. Indications included hemispheric (n = 79), vertebrobasilar (n = 56), upper extremity (24), and internal mammary/cardiac ischemia (n = 5), asymptomatic severe common carotid disease (n = 33), or other (n = 3). Primary atherosclerotic innominate (n = 6), common carotid (n = 84), and subclavian (n = 66) lesions underwent reconstruction. Thirty-one operations were performed for multiple trunk involvement, recurrent disease, arteritis, infection, dissection, coarctation, or aneurysm. There were 122 bypass grafting procedures (98 ipsilateral, 24 contralateral) and 60 arterial transpositions.nnnRESULTSnOne death (0.5%) and 7 nonfatal strokes (3.8%) occurred, none in patients who were asymptomatic. Perioperative morbidity included four asymptomatic occlusions (2%), 6 myocardial infarctions (3%), 10 pulmonary complications (5%), and 2 graft infections (1%). Follow-up periods ranged from 1 to 190 months (mean, 53 +/- 5 months). Nineteen patients (10%) were lost to follow-up. Fifty-seven late deaths occurred, most from cardiac causes. Seven reconstructions necessitated late revision. The cumulative primary patency rate at 5 and 10 years was 91% +/- 2% and 82% +/- 5%, respectively. The survival rate at 5 years was 72% +/- 4% and at 10 years was 41% +/- 6%. The stroke-free survival rate was 92% +/- 2% at 5 years and 84% +/- 2% at 10 years.nnnCONCLUSIONnCervical reconstruction of symptomatic and asymptomatic supra-aortic trunk lesions carries acceptable death and stroke rates and provides a long-term patient benefit. This should be the preferred approach for asymptomatic lesions and for patients with significant comorbidity because it carries less morbidity than direct transmediastinal aortic-based reconstruction.

Perioperative and late outcome in patients with left ventricular ejection fraction of 35% or less who require major vascular surgery

Survival in patients with diminished left ventricular ejection fraction (EF) is reduced after major vascular surgery. The objective of this study was to determine perioperative (30-day) and subsequent outcome after major vascular surgery in those with severe cardiac dysfunction, defined by EF being 35% or less (normal EF greater than 50%). From Aug. 1, 1984 to Jan. 1, 1988, 35 patients with EF equal to 27.7% +/- 6.1% (mean +/- 1 standard deviation) have required 47 major vascular procedures: 53% (n = 25) were limb revascularizations; 21% (n = 10) were direct aortoiliac aneurysm repairs: 23% (n = 11) were carotid endarterectomies: one patient had transaortic renal endarterectomy. Two deaths occurred within the first 30 days, yielding a 4.3% perioperative mortality rate (2 of 47 procedures). The cumulative mortality rate for the entire group during follow-up of 410 +/- 390 days was 40% (14 of 35 patients). Most late deaths (71%) occurred within the first 6 months after surgery and each was due to cardiovascular complications. Survival for those with an EF of 29% or less was significantly worse than for those with an EF greater than 29%, determined by life-table analysis (p less than 0.012, Mantel-Cox). The cumulative mortality rate was 59% with an EF of 29% or less and 18% in those with an EF greater than 29% (p less than 0.029, two-tailed Fisher exact test). The perioperative mortality rate for those with an EF of 35% or less who require major vascular surgery is acceptable, but overall survival during follow-up is diminished.(ABSTRACT TRUNCATED AT 250 WORDS)

The role of peroperative radionuclide ejection fraction in direct abdominal aortic aneurysm repair

Abstract Preoperative radionuclide ventriculography was performed in 60 patients to assess whether such testing could define those at increased risk after direct abdominal aortic aneurysm (AAA) repair. None of the patients had prophylactic coronary artery reconstruction to reduce the risk of AAA repair despite angina in 27% and previous myocardial infarction (MI) in 42%. The mean ejection fraction (EF) was 52% ± 15% (range 14% to 78%). Low EF (normal greater than 50%) was present in 40%, whereas ventricular wall motion abnormalities were present in 39% of patients. The overall perioperative (30-day) mortality rate was 5%. MI occurred in 7% within 30 postoperative days; none was fatal. Life-table analysis revealed that overall survival after AAA repair was significantly lower in patients with an EF of 50% or less ( p p = 0.003, Mantel Cox). There was a marked difference in the cumulative mortality rate during followed-up, being 50% in those patients with an EF of 35% or less (n = 10) compared with 14% in those with an EF greater than 35% (n = 50, p = 0.036, Fisher exact test). There was no statistical difference in the incidence of perioperative MI or perioperative death for those with an EF of 35% or less vs EF greater than 35%. An EF of 35% or less is not associated with a statistically significant increase in the incidence of perioperative MI or perioperative death after direct AAA repair but is associated with significantly reduced overall survival after surgery. Although patients with severe left ventricular dysfunction tend to survive the operation and the 30-day postoperative period, the reduction in overall survival decreases the potential benefit from direct AAA repair in those patients with an EF of 35% or less. Radionuclide ventriculography can define a group with reduced overall survival direct AAA repair. (J VASC SURG 1988;8:128-36.)