Combined carotid endarterectomy and coronary artery revascularization: a sobering review

The clinical outcome of 99 patients who underwent combined single-stage carotid thromboendarterectomy and coronary artery bypass grafts in three different hospitals over a 15-year period was analyzed. Coronary revascularization was elective in 16 patients, urgent in 46 and emergent in 37 patients. Asymptomatic carotid artery stenosis of greater than or equal to 80% was detected in 79% of patients. Sequential reconstruction of the carotid artery circulation followed by restoration of the coronary circulation was performed in all patients by two separate surgical teams. The population included 79 men and 20 women, with a mean age of 67 +/- 6 years, of whom 53% had a previous myocardial infarction, 59% had hypertension and 49% had a history of smoking. Three or more coronary arteries were revascularized in 90% of patients. The overall major neurological complication rate was 25%, with an 11% stroke rate ipsilateral to the operated carotid. Other major complications included respiratory failure (5%), multisystem failure (8%), and myocardial infarction (8%). The overall mortality was 12%. Ten of the 12 deaths were directly related to the cardiac operation, and 2 died as a result of stroke. We conclude that a combined carotid and coronary artery operation results in a high morbidity and mortality in institutions with excellent records for each operation when performed separately. Whenever possible, these high risk patients should be carefully assessed regarding the need for both procedures, since prophylactic carotid endarterectomy has not been shown to significantly reduce the neurologic risk of coronary bypass.

Randomized placebo-controlled, double-blind trial of ketanserin in treatment of intermittent claudication

Ketanserin, a selective serotonin (5-HT) antagonist at 5-HT2 receptors, was investigated in a 12-month, double-blind placebo-controlled study in 35 patients with intermittent claudication. Benefit was assessed by repeated treadmill tests, recording claudication distance, and by measurement of Doppler ankle-brachial pressure indices (ABPI) and pulse volume recordings (PVR). Improvement in claudication distance of 42-44% was noted during the 12 months of the double-blind study and this trend continued to 53-67% during an additional 3 month run-out period on placebo. There were no significant differences between the group given Ketanserin and the placebo group. The hemodynamic measurements demonstrated no statistically significant change in either ABPI or PVR throughout the study period, and no significant differences between the two groups. The conclusion of the study indicates that Ketanserin is ineffective in the treatment of intermittent claudication.

Reduction in thrombus formation by placement of endovascular stents at endarterectomy sites in baboon carotid arteries

BACKGROUND

Although antithrombotic therapies with aspirin, dipyridamole, and heparin have decreased thrombo-occlusive events, they have not abolished these complications. Endovascular mechanical support, first reported by Dotter in 1969, has been proposed as a means to reduce both acute and chronic vessel closure by providing a supporting framework for the disrupted and sometimes dissected arterial wall.

METHODS AND RESULTS

To determine the effects of placing self-expanding stainless steel wire endoprostheses on the accumulation of thrombus at sites of carotid artery endarterectomy we measured platelet deposition continuously for 90 minutes and at 24 and 48 hours by gamma camera imaging of autologous 111In-labeled platelets in six stented and nonstented endarterectomized baboons that received heparin but no antiplatelet agents. At nonstented endarterectomy sites 5.36 +/- 1.25 x 10(8), 4.78 +/- 0.98 x 10(8), and 4.55 +/- 0.81 x 10(8) platelets per cm were deposited at 30, 60, and 90 minutes, respectively. In contrast, stented endarterectomy sites accumulated 0.99 +/- 0.31 x 10(8), 0.66 +/- 0.33 x 10(8), and 0.80 +/- 0.36 x 10(8) platelets per cm at 30 minutes (p = 0.02), 60 minutes (p = 0.004), and 90 minutes (p = 0.002), respectively. Platelet deposition remained reduced at 24 and 48 hours in stented endarterectomized carotid arteries (ECAs) when assessed as a ratio between net radioactivity in the endarterectomized region versus whole blood radioactivity (p = 0.006 and p = 0.009, respectively). Both stented and nonstented ECAs remained patent acutely, although two of six nonstented ECAs occluded by 30 days. By comparison 11 of 14 nonstented ECAs remained patent in another group of control animals. Scanning electron microscopy of control and stented arteries at 30 days demonstrated equivalently confluent endothelium.

CONCLUSIONS

We postulate that endovascular stents reduce the thrombogenic effects of flap formation, tearing, dissection, and vasospasm in ECAs.

Pulse volume recording disturbances in paraplegic patients

Spinal cord injuries may modify vascular reactivity in the denervated region. This study presents an original observation of altered vascular response in paraplegic patients. A group of 30 consecutive paraplegic otherwise normal individuals underwent a thorough vascular examination. There were 29 male and 1 female patient, 21 to 67 years old (average 41), all with traumatic spinal cord injury. Average time since injury was 17 years. All had good peripheral pulses and normal segmental Doppler pressure measurements. In 8 patients, plethysmography--pulse volume recording (PVR) was normal as expected. In 22 patients an unusual feature of the vascular examination was recorded, consisting of normal peripheral arterial pressures with PVR waveforms indicating poor pulsatility. This group was older than the group with normal studies: ages 44 +/- 13 vs 34 +/- 8 years (p = 0.05), and more time had elapsed since injury-20 +/- 12 vs 10 +/- 4 years (p = 0.015). The altered pulsatility demonstrated in most of those paraplegic patients may play a role in deficient wound healing frequently observed below the level of spinal neurological loss.

Hirudin interruption of heparin-resistant arterial thrombus formation in baboons

To determine the role of thrombin in high blood flow, platelet-dependent thrombotic and hemostatic processes we measured the relative antithrombotic and antihemostatic effects in baboons of hirudin, a highly potent and specific antithrombin, and compared the effects of heparin, an antithrombin III-dependent inhibitor of thrombin. Thrombus formation was determined in vivo using three relevant models (homologous endarterectomized aorta, collagen-coated tubing, and Dacron vascular graft) by measuring: (1) platelet deposition, using gamma camera imaging of 111In-platelets; (2) fibrin deposition, as assessed by the incorporation of circulating 125I-fibrinogen; and (3) occlusion. The continuous intravenous infusion of 1, 5, and 20 nmol/kg per minute of recombinant hirudin (desulfatohirudin) maintained constant plasma levels of 0.16 +/- 0.03, 0.79 +/- 0.44, and 3.3 +/- 0.77 mumol/mL, respectively. Hirudin interrupted platelet and fibrin deposition in a dose-dependent manner that was profound at the highest dose for all three thrombogenic surfaces and significant at the lowest dose for thrombus formation on endarterectomized aorta. Thrombotic occlusion was prevented by all doses studied. In contrast, heparin did not inhibit either platelet or fibrin deposition when administered at a dose that maximally prolonged clotting times (100 U/kg) (P greater than .1), and only intermediate effects were produced at 10-fold that dose (1,000 U/kg). Moreover, heparin did not prevent occlusion of the test segments. Hirudin inhibited platelet hemostatic function in concert with its antithrombotic effects (bleeding times were prolonged by the intermediate and higher doses). By comparison, intravenous heparin failed to affect the bleeding time at the 100 U/kg dose (P greater than .5), and only minimally prolonged the bleeding time at the 1,000 U/kg dose (P less than .05). We conclude that platelet-dependent thrombotic and hemostatic processes are thrombin-mediated and that the biologic antithrombin hirudin produces a potent, dose-dependent inhibition of arterial thrombus formation that greatly exceeds the minimal antithrombotic effects produced by heparin.

[Surgery for thoraco-abdominal aortic aneurysm]

12 patients underwent resection of a thoraco-abdominal aortic aneurysm. There were 10 men and 2 women, ranging in age from 54-78 years (mean 65). Aortic arteriosclerosis was the primary etiology in 11, and Behcet's disease in the other 1. Most patients (7/12) presented with Type 3 aneurysm, extending from the distal descending thoracic aorta to the distal abdominal aorta; none had aortic dissection. 11 were operated on for symptoms related to the aneurysm: 3 of these had a contained rupture. The risk factors were chronic obstructive pulmonary disease in 10, hypertension (10), diffuse arteriosclerosis (8), ischemic heart disease (6), chronic renal failure (5) and cerebrovascular accident (1). The surgical technique in 11 was graft inclusion and visceral vessel reattachment. The main complication was acute renal failure, seen in 3 patients. None had spinal ischemia. Operative mortality was 33%. Of the 4 who died, 2 had myocardial infarction and 2 uncontrolled intraoperative bleeding. According to the literature the major complications are spinal cord ischemia and renal failure.

Inter- and intrasexual dimorphisms in the vocal control system of a teleost fish: motor axon number and size

In one species of vocalizing fish, the plainfin midshipman (Porichthys notatus), large, nest-guarding males ('type I') use striated muscles to produce acoustic communication signals that include short duration (less than 1 s) 'burps' important in agonistic encounters and long duration (in the order of minutes) 'hums' which function in attracting females to nest sites during the breeding season. Females, and a second group of smaller reproductively active males ('type II') that 'sneak' spawn, do not generate hums, although they produce burps. Differences in vocal behavior are paralled by a relative increase of 6-fold in the sonic muscle of type I males. Inter- and intrasexual dimorphisms in sonic muscle mass were matched by those in the cross-sectional area of sonic motor axons, but not by those in number of axons. Thus, axon size was 2- to 3-fold larger in type I males than in females, type II males, or juveniles, none of which differed significantly from each other. Axon number was similar between type I males and females of a similar body size, despite the extreme dimorphism in sonic muscle mass. Axon number, however, was slightly greater (0.1-fold) in type I males and females compared to the smaller-sized juveniles and type II males. Type II males, in comparison to the non-reproductive juvenile males, have gonads that are about 20-fold larger and produce mature sperm. Nevertheless, the two groups resemble each other in body and swimbladder size, as well as sonic motor axon size and number. This suggests that type II males represent a subset of juvenile males that undergo precocious gonadal hypertrophy and spermiogenesis, but retain juvenile-like nongonadal traits. The results are discussed within the context of the development of vertebrate motor systems as well as the evolution of alternative reproductive tactics among teleost fishes.

Evolution of homologous vocal control traits

Evolutionary neurobiologists want to know how neuronal properties (or traits) have been modified to subserve adaptive changes in behavioral phenotypes. Homology can provide a conceptual framework to distinguish the separate contributions of phylogenetic factors and current adaptive modifications to extant traits and behaviors. In this essay, a suite of nine vocal/sonic motor traits are compared in two orders of teleost fishes, the Batrachoidiformes and Scorpaeniformes. Only three of the traits are modified among Scorpaeniformes, the more advanced group. The large number of conserved characters among the study species suggests their sonic motor systems are homologs. This conclusion is consistent with the known phylogeny of teleosts and further implies that homologous sonic motor traits are more extensively modified among more recently evolved members (in this case the Scorpaeniformes) of the teleostean lineage. Since homology implies a common ontogenetic history for any trait, modifications thereof can potentially be linked to changes in identifiable developmental events, which themselves are homologs. Several hypotheses are proposed to account for the origins of modified sonic traits. The further demonstration that modified traits of the sonic motor system are in fact adaptations sets the stage for behavioral ecological studies that attempt to understand why the modified traits underlie behavioral changes that increase an individual's fitness.

Comparison of transcranial and cervical continuous-wave Doppler in the evaluation of intracranial collateral circulation

Adequate intracranial collateral circulation reduces risk of stroke in carotid artery surgery. To evaluate their relative accuracies in assessing intracranial collateral blood flow, we prospectively compared transcranial Doppler and continuous-wave Doppler of the cervical carotid arteries combined with compression of the common carotid artery in 28 consecutive patients before carotid endarterectomy. Ten healthy volunteers served as controls. Three patients (11%) were excluded from compression of arteries because of diffuse disease in the common carotid artery. A total of 199 compressions were performed without complications. Lack of a suitable transtemporal window precluded the performance of transcranial Doppler in three patients (12%). The anterior communicating artery was identified in all the normal volunteers and 80% of patients by both methods. The posterior communicating artery was identified by both methods in 16 of 20 attempts in controls. Continuous-wave Doppler identified the posterior communicating artery in 30 of 50 attempts in patients; transcranial Doppler identified the posterior communicating artery in 20 of 44 attempts in patients (p greater than 0.5). Detection of intracranial collaterals correlated with intraoperative carotid artery back pressure measurements in 23 of 25 patients (92%). We conclude that continuous-wave Doppler of the extracranial arteries combined with common carotid artery compression is a safe and easy way to detect intracranial collaterals, with an accuracy equivalent to transcranial Doppler.

Sexual dimorphisms in the vocal control system of a teleost fish: ultrastructure of neuromuscular junctions

In the sound-generating fish, Porichthys notatus, large, nest-guarding 'Type I' males use their swimbladder 'drumming' muscles to produce acoustic communication signals. Females and another group of smaller sexually mature males ('Type II') have not been observed to produce sounds. Electron microscopy was used to compare the morphology of the neuromuscular junctions in vocalizing Type I males to those of Type II males and females. Significant differences were seen in synaptic vesicle density, terminal size, degree of terminal invagination below the muscle fiber surface, number of Schwann cell processes along the non-synaptic boundary of boutons, and the number of boutons per innervation site.

Utility of computed tomography for surveillance of small abdominal aortic aneurysms. Preliminary report

To assess the ability of computed tomography to predict the potential for expansion of small abdominal aortic aneurysms, we analyzed the computed tomographic scans of 30 patients who had two or more abdominal computed tomographic scans at least 6 months apart between 1979 and 1989. Clinical variables and 10 defined objective characteristics of computed tomography were evaluated. Twenty-five men and five women with abdominal aortic aneurysms ranging from 30 to 64 mm (mean, 45 mm) were followed up with serial computed tomographic scans for a mean (+/- SE) of 26 +/- 3 months. In 19 patients, enlargement of aneurysm diameter of 3 mm or more on serial computed tomographic scans was noted, whereas in 11, there was little or no expansion. Of the clinical variables studied, only serum cholesterol correlated with an increased risk of expansion. Thrombus area, measured by computed tomography, was 7.3 +/- 0.9 cm2 in enlarging aneurysms vs 4.3 +/- 0.9 cm2 in stable aneurysms. Based on these preliminary data, we conclude that computed tomography may provide valuable information about the likelihood of future expansion of small abdominal aortic aneurysms.

Propagation of deep venous thrombosis identified by duplex ultrasonography

To investigate the efficacy of anticoagulation in preventing continuing thrombosis, we prospectively evaluated 24 patients with acute deep venous thrombosis using duplex ultrasonography. All patients were hospitalized with conclusive ultrasonic evidence of deep venous thrombosis identified in one of four levels: I, calf only; II, calf-popliteal; III, calf-popliteal-femoral; or IV, calf-popliteal-femoral-iliac. Duplex scans were obtained on admission and on three subsequent occasions during therapy. Progression of thrombosis was defined as advancement of thrombus to the more proximal venous level. Demographic data, symptoms, risk factors for deep venous thrombosis, physical findings, anticoagulation regimens, and hematologic variables were ascertained. Adequacy of anticoagulation was defined as elevation of baseline activated partial thromboplastin time by 150%. Nine patients (38%) had progression of thrombosis, and 15 (62%) had stable or improving duplex scans. Progression occurred as follows: I----II (2), I----III (2), II----III (1), and III----IV (4). Of the demographic and clinical variables examined, only smoking correlated with progression of thrombus (p = 0.04). Average heparin dose in the stable group was 1214 +/- 294 units/hr and 1122 +/- 248 units/hr in the group that progressed (p = 0.8): activated partial thromboplastin time was 45.6 +/- 7 seconds in the stable group and 49.8 +/- 9 seconds in the progression group (p = 0.7). Nine patients in the stable group had consistently adequate anticoagulation, whereas six did not; six in the progression group were consistently anticoagulated, and three were not. Two patients (one with stable thrombus and one with progressive thrombus) suffered nonfatal pulmonary emboli. Clot progression as determined by duplex scanning did not predict acute complications of deep venous thrombosis.

Aspirin-independent antithrombotic effects of acutely attached cultured endothelial cells on endarterectomized arteries

We have compared the acute antithrombotic effects of aspirin-treated versus normal endothelial cell (EC) coverage of endarterectomized baboon aortic segments (EAS) incorporated into chronic exteriorized arteriovenous shunts in baboons. Human ECs grown in culture were incubated in control medium or medium containing aspirin (100 mumols/ml) and then attached at saturation density by incubating EC suspensions (6 x 10(5) cells/100 microliters) within EAS for 20 minutes. Nonendarterectomized aortic segments and untreated EAS served as negative and positive controls, respectively. The inhibitory effect of aspirin treatment on EC production of prostacyclin was confirmed by radioimmunoassay of its stable metabolic breakdown product, 6-keto-prostaglandin F1 alpha in supernatant medium. Thrombus formation in vivo was measured as the accumulation of indium 111-labeled platelets on endarterectomy sites in real time by scintillation camera imaging. 111In-labeled platelets were deposited rapidly, reaching a plateau by 60 minutes of 4.40 +/- 0.89 x 10(9) platelets/cm, compared with 111In-labled platelet deposition on nonendarterectomized segments of 0.89 +/- 0.26 x 10(9) platelets/cm (p = 0.008). Coverage of EAS with normal cultured ECs significantly reduced platelet deposition on EAS (1.05 +/- 0.45 x 10(9) platelets/cm; p = 0.009 at 1 hour compared with EAS not incubated with ECs). Aspirin-treated ECs also produced a marked reduction in platelet disposition (0.71 +/- 0.24 x 10 platelets/cm; p = 0.007 compared with EAS without ECs) that was equivalent to the effect of non-aspirin-treated ECs (p greater than 0.5). Scanning and transmission electron microscopy confirmed the antithrombotic effects of attached ECs. We conclude that endarterectomy of normal arteries produces a highly thrombogenic surface and the thrombogenicity is abolished by acutely attaching cultured human ECs.

Heparin-resistant thrombus formation by endovascular stents in baboons. Interruption by a synthetic antithrombin

Intravascular mechanical support has been proposed as a solution to the frequent occurrence of vascular narrowing and occlusion after transluminal balloon angioplasty or surgical endarterectomy. Although several endovascular stents are currently in clinical use for angioplasty of larger vessels, acute thrombosis is a troublesome complication of their use with coronary angioplasty. To study thrombus formation associated with metallic mesh endoprostheses, we have evaluated stents placed inside 3-mm expanded polytetrafluoroethylene (ePTFE) grafts incorporated into chronic exteriorized arteriovenous silicone rubber shunts in baboons. We have also compared the antithrombotic capacities of heparin and the synthetic antithrombin D-phenylalanyl-L-prolyl-L-arginyl-chloromethylkene (D-FPRCH2Cl) to interrupt this platelet-dependent process for two different endovascular stents. Acute platelet deposition was continuously measured during 1 hour using gamma camera imaging of platelets labeled with indium-111 oxine. On untreated control ePTFE grafts (n = 11), 0.87 +/- 0.15 x 10(9) platelets/cm were deposited during 60 minutes. In contrast, balloon-expandable endovascular stents within ePTFE (n = 6) accumulated 4.37 +/- 0.68 x 10(9) platelets/cm (p = 0.003 compared with controls), and self-expandable stents (n = 6) accumulated 3.91 +/- 0.42 x 10(9) platelets/cm (p = 0.006 compared with controls); no difference between stents was detected in this test system (p greater than 0.5). Systemic heparin treatment did not reduce platelet deposition (4.20 +/- 0.41 x 10(9) platelets/cm at 60 minutes; p greater than 0.5).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of hypoxaemia on enzymes supplying myocardial energy in children with congenital heart disease

The differences in energy metabolism of the myocardium in children with congenital cardiac malformations producing hypoxaemia (arterial oxygen saturation 77 +/- 2%) or normoxaemia (arterial oxygen saturation 94 +/- 2%) were analysed by measuring the activity of the representative energy-supplying enzymes. Right atrial and ventricular tissue samples were obtained during surgical interventions. We demonstrated that myocardial metabolism was significantly influenced by hypoxaemia: the aerobic capacity of the energetic metabolism was reduced both in the atriums and ventricles. Atrial myocardium was more affected: in addition to citrate synthase, the activity of enzymes connected with lactate uptake and carbohydrate catabolism was also significantly decreased. These results demonstrate that the human heart is able to adapt to hypoxaemia by changing its energetic metabolism.

Intraoperative transcranial Doppler: limitations of the method

To test the hypothesis that the transcranial Doppler is a useful technique for intraoperative neuromonitoring, we prospectively used it to study 83 patients undergoing carotid end-arterectomy. A 2 MHz pulsed-wave, range-gated transcranial Doppler was positioned at the transtemporal window after induction of general anesthesia. Mean middle cerebral artery velocity, intraarterial blood pressure, end-tidal PCO2, heart rate, and a spectral array of electroencephalographic activity were recorded continuously throughout the operation. Internal carotid artery back pressure was measured routinely. On completion of the endarterectomy, duplex ultrasound examinations and arteriograms were uniformly obtained to assess technical adequacy. Forty-nine of the 83 patients (60%) had complete preoperative and intraoperative transcranial Doppler examinations. Eleven (13%) had incomplete assessments because of small or absent transtemporal windows. Twenty-three (27%) had unsuccessful monitoring because of technical difficulties, primarily because of inability to maintain probe position--with loss of mean middle cerebral artery velocity recording. In the patients with complete studies, transcranial Doppler failed to provide information that altered surgical therapy. All monitoring modalities were normal in the one patient (1.2%) who sustained an operative stroke. We conclude that at this time, transcranial Doppler has not been useful to routinely monitor the intraoperative events during carotid endarterectomy.

The elusive isolated hypogastric artery aneurysm: novel presentations

Isolated aneurysms of the internal iliac artery are rare. Their anatomic location makes them true pelvic aneurysms and they may grow to a large size undetected. Their late recognition may be prompted by rupture or symptoms related to compression of neurologic, gastrointestinal, genitourinary, or venous structures. We have encountered three isolated hypogastric artery aneurysms with unique presentations. In one patient with bilateral isolated hypogastric artery aneurysms, one ruptured into the bladder, and at a later time the other caused ureteral obstruction. Another patient had obturator neuropathy as a result of his aneurysm. In the patient with large bilateral aneurysms, one was detected by rectal examination, and the other was found by palpation of the abdomen. The second patient with a smaller aneurysm required examination of the pelvis by CT scanning to establish the diagnosis. Awareness of the existence of these lesions is required to identify such patients who describe symptoms uncommonly associated with abdominal aneurysms. Operative management consisted of exclusion of the aneurysm and partial or complete aneurysmorrhaphy with preservation of iliac arterial flow to maintain extremity perfusion. Recovery was complete in each instance. A review of published cases is presented.

[Adaptation of cardiac energy metabolism in children with congenital heart defects]

Metabolic differences of the cardiac muscle in children with normoxaemic and hypoxaemic congenital heart disease were analyzed by means of representative enzymes of the energy metabolism in 95 specimens in 80 children with congenital heart disease. Tissue specimens from the right atria and ventricles were obtained during surgical operations. It was revealed that the myocardial metabolism of patients with congenital heart disease was markedly influenced by hypoxaemia: the aerobic capacity was significantly reduced in the atria as well as in the ventricles. Changes in the atrial musculature were, however, more marked: in addition to citrate synthase - similarly as in the ventricles - in the atria also activities of enzymes associated with lactate metabolism (LDH) and with glycolysis (TPDH, GPDH) were reduced. Patients with an atrial septal defect had a significantly lower activity of the enzyme involved in the fatty acid breakdown (HOADH) than patients with a ventricular septal defect. The described new adaptive mechanism is of practical importance for the treatment of congenital heart disease and other conditions associated with prolonged hypoxaemia.

[Differences in the activity of enzymes associated with energy metabolism in the heart atria and ventricles in children]

Tissue specimens from the right atrium and ventricle of the same heart were obtained during surgery in 45 children operated on account of congenital heart disease (tetralogy of Fallot and ventricular septal defect). Significant differences were found in the enzyme activities between the atrial and ventricular musculature. The activities of enzymes associated with aerobic metabolism (citrate synthase, malate dehydrogenase, with lactate metabolism) lactate dehydrogenase (and the fatty acid oxidation) hydroxyacyl-SoA-dehydrogenase) were significantly higher in the ventricular musculature. Hexokinase, the enzyme responsible for glucose phosphorylation was on the other hand, significantly higher in the atria. From this ensues that the right ventricle can utilize and oxidize to a full extent all main nutrients (fatty acids, glucose and lactate), while the right atrium utilizes above all glucose. These atrio-ventricular differences do not depend on the type of the congenital heart disease and it may be assumed that they exist also in healthy subjects.

Pharmacokinetic activity of nitrites evaluated by digital pulse volume recording

Evaluation of the pharmacological properties of vasoactive drugs using routine pharmaco-chemical methods is often complex, time consuming and expensive. We used finger plethysmography for the evaluation of the bioactivity of two long-acting nitrite preparations. Eight healthy male volunteers were exposed to four different drugs: (1) Nitroglycerin; (2) Placebo; (3) Isosorbide dinitrate as Isotard Forte; (4) Isosorbide dinitrate as Cordil-40 SR. Digital pulse volume recording (PVR) was monitored for twelve hour periods. The shape of the PVR curve was used to calculate the diastolic amplitude response intensity, an indication of the vasoactive effect of the drug. There was no measurable response to the administration of placebo. The effect of nitroglycerin was maximal one hour after administration and disappeared after three hours. The long term effect of the two long-acting nitrite preparations was clearly demonstrated as compared to nitroglycerin. Noninvasive measurements of peripheral blood flow can serve as a convenient and accurate tool for pharmacokinetic studies of vasoactive drugs.

Scoring of vascular disease in the lower extremities

Lack of standardisation in reporting the vascular status of patients leads to difficulties in comparing different series. A method of vascular scoring is presented, integrating symptoms, physical examination, vascular laboratory studies and arteriography. The score is expressed in a concise form by several letters and numbers supplying the relevant information as to the main segment involved, the severity of the ischaemia and the completeness of the examination. The files of 100 candidates for vascular surgery were recorded with the scoring method. Vascular indices were calculated by dividing the sum of points assigned to each item by the maximal available score. The internal consistency of the method was evaluated by computing separate indices for the three components of the scoring--clinical examination (CE), vascular laboratory (VL) and arteriography (AR)--and comparing them with the overall index and with each other. Correlation coefficients with the overall index were for CE 0.90, for VL 0.92 and for AR 0.75. The data on the 200 limbs were reviewed independently by three experienced vascular surgeons and ranked in order of increasing severity of ischaemia; the correlation coefficient between this ranking and one based solely on the scoring method was 0.91. A vascular scoring method may help create a mutual language among practitioners, enabling them to compare results and benefit from accumulating worldwide experience.

[Carotid endarterectomy]

Carotid endarterectomy was performed 77 times in 73 symptomatic patients. In 67 of them there had been 1 or more transient ischemic attacks (TIA), in 4 transient atypical symptoms, and in 2 mild persistent neurological deficits. After operation 1 died of a stroke and 1 had a nonfatal myocardial infarction. In 3.3% of 33 low-risk patients (Sundt's classes 1 and 2) there was mild postoperative neurological deficit. The rate of neurological complications was much higher in 40 high-risk patients (classes 2 and 3), including 5 with postoperative stroke. Followup averaged 21.5 months (longest 54 months), the 5-year survival (by extrapolation from a life table analysis curve) was 87%, and there was only 1 fatal stroke. Those who recovered from operation without complications had an 86% chance of having no further neurological problems.

[Energy-supplying metabolism of the volume overloaded and hypoxia stressed heart in children]

This study summarizes results obtained with regard to atrial and ventricular enzymes of energy supplying metabolism in children with different types of congenital heart disease. In all groups of patients - normoxemic as well as hypoxemic - significant atrio - ventricular differences were observed: the right ventricle is amply equipped for utilization and oxidation of all major nutrients, while the right atrium utilizes glucose predominantly. Myocardial metabolism in children with congenital heart disease was significantly influenced by hypoxemia: the capacity of aerobic enzymes in cyanotic patients was significantly lower, both in atrial and ventricular tissue, whereby the atrial changes were even more striking. No marked differences were found between atrial and ventricular septal defects in normoxemic patients; the only difference was a lower capacity of fatty acid catabolism in children with atrial septal defect.

Tube graft replacement of abdominal aortic aneurysm: is concomitant iliac disease a contraindication?

One hundred and fifty nine patients underwent surgery for abdominal aortic aneurysm (AAA) from 1975 to 1985. Of these, a tube graft was inserted in 86 patients (55.1%). Immediate and late results of these 86 patients were evaluated retrospectively as to the effect of concomitant common iliac artery (CIA) disease on early and late results. There were 77 males and nine females aged 35-91 (average 70.7) years. Surgery was elective in 44 patients (51.2%), and as an emergency due to expanding, ruptured or thrombosed AAA in 42 patients (48.8%). The CIAs showed unilateral or bilateral aneurysmal dilatation or atherosclerotic changes in 47 patients (54.7%). At the time of surgery additional bypass grafting from the tube graft to one femoral artery was performed in four patients, and patch angioplasty to the CIA in one. Operative mortality was 4.6% (two patients) in the elective group, and 45.2% (19 patients) in the emergency operations. Follow-up was 94% complete for a mean of 4.1 (range 0.5-10) years). Late mortality for the whole series was 20.0% (12 patients). Only one patient died of a cause related to the AAA operation. All but one of the 48 late survivors are free of any peripheral vascular problems. We conclude that tube graft replacement of AAA is a good choice even in the presence of some degree of CIA atherosclerosis or aneurysmal dilatation.

Clinical presentation of suspected carotid artery disease. Screening of candidates for arteriography with the assistance of the vascular laboratory

The evaluation of suspected carotid artery disease was reviewed in a consecutive series of 292 patients referred by attending physicians in a university hospital. Twenty-three percent of the patients presented with classical transient ischemic attacks, and all those suitable for eventual surgery were recommended for arteriography. In 75% of the patients the presenting symptoms were nonlateralizing or equivocal. In this group the results of noninvasive vascular tests were decisive as to the recommendation for arteriography, which was positive in 79% of those performed. Among 100 surveyed patients who did not undergo arteriography, cerebrovascular accidents occurred in 3 patients: carotid disease was detected in 2 of them, in whom arteriography had been postponed for clinical reasons, while in the third a subsequent arteriography demonstrated no carotid lesion. Expert clinical assessment assisted by vascular studies prevented unnecessary arteriography in 62% and detected carotid pathology with atypical presentation in 13% of the patients.

Jejunogastric intussusception. A new diagnostic test

Jejunogastric intussusception is a rare complication of gastrojejunal reconstruction of unknown cause. There are two types of jejunogastric intussusception: the acute type, presenting as a surgical emergency, and the chronic intermittent type, which is difficult to diagnose and is usually of mild symptomatology but which may progress to the acute type with the incarceration of the intussusceptum. With two case reports and a literature review, an endoscopic diagnostic maneuver is proposed, hinting at disordered motility with reversed peristalsis as a possible causative factor. Corrective surgical treatment to prevent recurrence and incarceration in chronic cases is advocated. Treatment should include dismantling of the efferent loop, which is the most frequent intussusceptum.

Renovascular hypertension in spontaneous hypertensive rats: an experimental model of renal artery stenosis superimposed on essential hypertension

Renovascular hypertension superimposed on essential hypertension, a condition encountered in the elderly, was studied. An experimental animal model consisting of a two-kidney one-clip Goldblatt preparation in the spontaneous hypertensive (SHR) rat, that would simulate this condition, was designed. A 0.25 mm silver clip was placed on the left renal artery of SHR male rats. The same procedure performed on WKY rats served as control. All experiments were performed on low, normal, and rich sodium diet. Systolic blood pressure (BP) was measured by tail-cuff method. Plasma renin concentration (PRC) was determined before and after clipping of the renal artery. Results were as follows: Mean systolic BP increased significantly in clipped rats fed with normal and rich sodium diets. SHR showed an increase from 144 +/- 3 (mean + s.e.m.) to 168 +/- 3 mmHg, and WKY rats showed an increase from 120 +/- 2 to 139 +/- 5 mmHg. There was a two- to threefold rise in PRC. A low-salt diet given prior to clipping prevented the appearance of renovascular hypertension despite a significant rise in PRC. We concluded that renal artery narrowing plays a significant role in the rise of BP in the basically essential type of hypertension.

Simplified assessment of arterial graft patency using indium-labelled-platelet scintigraphy

Arterial grafts were studied with indium-III-labelled platelets in 13 patients (18 graft limbs) in the early post-implication period. Platelet thrombogenic activity was graded into four grades by visual inspection of the images, and scintigraphic criteria of impending graft occlusion were defined. Dacron and polytetrafluoroethylene grafts had similar high thrombogenic activity in comparison with autologous veins. Nine graft studies showed patterns of radioactivity concentration that suggested threatening thrombosis and eight of these eventually occluded. In nine other studies absent to moderate radiolabelled platelet activity was observed and none occluded within a mean follow-up period of 24 months. Prediction of graft occlusion of scintigraphic evaluation using the present simple non-invasive technique is valuable since corrective measures may be instituted earlier and with greater success in the post-operative follow-up period.

Percutaneous transluminal angioplasty of the distal abdominal aorta and its bifurcation

Percutaneous transluminal angioplasty (PTA) of stenotic lesions in the distal abdominal aorta and its bifurcation was performed in 14 patients, 6 of whom were women. The stenotic segment in the aorta or aortic bifurcation was usually the only significant lesion. The double-balloon technique was used in 12 patients via bilateral femoral artery catheterizations. In 2 other patients with aortic lesions, a single large balloon sufficed. Good results were achieved in all but 1 patient, with minor complications occurring in 3 instances. The follow-up period varied from 6 months to 5 years. We believe that PTA is the procedure of choice in treating localized lesions of the distal abdominal aorta and its bifurcation, especially when distal vessels are relatively uninvolved.

Percutaneous transluminal recanalization of common iliac artery occlusions

Percutaneous transluminal recanalization of occluded iliac arteries was attempted in 25 patients (26 limbs). In 22, successful recanalization was achieved, although 4 patients required additional surgical thrombectomy. The remaining 4 patients had surgical bypass procedures. The early and late results of percutaneous recanalization are presented as well as the technique used. We conclude that percutaneous recanalization of iliac occlusion is an effective procedure in the majority of cases. The option of surgical treatment remains viable when the percutaneous approach is unsuccessful.

Cardiovascular changes after bilateral upper dorsal sympathectomy. Short- and long-term effects

The effect of bilateral upper dorsal sympathectomy (UDS) on cardiac function was investigated in two groups of young healthy patients who underwent bilateral excision of T2 and T3 ganglia for palmar hyperhidrosis. In ten patients echocardiography of left ventricular function (LVF) was performed before operation and 2 weeks after operation. Electrocardiograms (ECG) were done before operation, during operation immediately after sectioning each sympathetic chain, and at 2 weeks after operation. The mean pulse rate decreased significantly in patients after they underwent bilateral UDS. There were no clinical arrhythmias or changes in LVF in any patient. Submaximal exercise testing and ECG tracings done at rest and after effort were obtained for 29 patients before undergoing bilateral UDS, 30 days after operation, and 1-3 more times within a 2-year postoperative period. Pulse rates taken at rest and after effort were significantly lower than those taken after operation, and the blood pressure response to exercise was blunted. ECG tracings showed a significant change in the electrical frontal plane axis and shortening of the QTc interval. These changes were evident 30 days after operation and persisted for 2 years. In conclusion, bilateral UDS has no overt arrhythmogenic effect in the young, healthy heart and its beta-blocker-like effect persists for at least 2 years.

Brachial artery injury. A complication of posterior elbow dislocation

A case is presented of a 32-year-old man who sustained a closed posterior dislocation of the left elbow. The dislocation was reduced immediately under intravenous sedation. When, after reduction, the pulse remained weak, angiography revealed a complete tear of the brachial artery. The artery was repaired with end-to-end anastomosis, resulting in a good radial pulse at the end of the procedure. Though dislocation of the elbow is a relatively common traumatic injury, associated brachial artery injury is rare. The authors note that the diagnosis of arterial trauma in such cases should rely heavily on angiography.

Percutaneous transluminal angioplasty. A suggested method for analysis of clinical, arteriographic, and hemodynamic factors affecting the results of treatment

Sixty-nine percutaneous transluminal angioplasties (PTAs) were performed in the iliac and the femoral arteries of 54 patients. The main factors that might affect the results were reviewed: associated diseases, severity of ischemic symptoms, location and type of lesions (stenosis or occlusion and their length), and presence of disease distal to the site dilated. The vascular status of the patients in our series was more severe than in most others. Improvement at follow-up (average 15 months) was maintained in 74% of 66 radiographically successful PTAs. Poor runoff was the only factor found to affect the outcome deleteriously. Intra-arterial pressure measurements performed during the procedure and vascular laboratory studies were most valuable in assessing immediate and long-term results. Wide variations in results of PTA published in the literature are due to differences in methods of selection, evaluation, and reporting. A plea is made for future presentations of PTA series in an analyzable and comparable way, including and correlating all relevant variables as in the model suggested by the present study.

Frequent occurrence of renal calculi in tuberculous kidneys in Israel

The incidence of renal calculi among renal tuberculous patients, hospitalized during thirty years in a medical center, was evaluated. It was found to be 24.5 per cent, most probably the highest figure so far reported in the medical literature.

Pulmonary embolism in post-mortem material with clinical correlations in 425 cases

425 patients with pulmonary emboli at post mortem were studied retrospectively with the main focus on the clinical diagnosis. The diagnosis of pulmonary embolus was made or suspected while the patient was still alive in 59 patients (14%) and was first written in the post mortem request form in 130 patients (30%). In 236 patients (56%) the diagnosis was made only at post mortem. Even in fatal emboli the diagnosis was missed in 43% of cases. A multiplicity of non specific symptoms and signs was observed with a minority of patients showing signs and symptoms considered as typical. Of 231 thrombophlebitis processes found in locations which could give rise to clinical symptoms in the lower extremities the diagnosis was noted only in 25 cases. Chest x-ray and ECG were negative in two thirds of the cases. The high rate of misdiagnosis derived from two reasons: (a) subjective factors: lack of awareness; (b) objective difficulties: lack of specificity of clinical symptoms and signs as well as of results of the routine tests (chest x-ray and ECG). Since sophisticated confirmative tests for pulmonary emboli will be performed only on the basis of clinical suspicion, clinical awareness based on the observations detailed in this survey is still the cornerstone of diagnosis.

Left renal vein division in abdominal aortic aneurysm operations. Effect on renal function

We examined the effect of left renal vein (LRV) division during abdominal aortic aneurysm operations on renal function during the recovery period. Fifteen patients with LRV division were compared with 26 patients in whom the LRV was not ligated. These two groups of patients did not differ significantly in any of their preoperative characteristics, operative management, or postoperative complications. Preoperative, highest postoperative, and predischarge levels of plasma urea and creatinine, as well as urinary sediment, were compared in both groups. Left renal vein division could not be implicated as a cause of renal function deterioration and was found to be a safe, useful adjunct to abdominal aortic aneurysm surgery.

Distribution and symmetry of arteriosclerotic lesions of the lower extremities: an arteriographic study of 200 limbs

Lower-extremity arteriograms of 100 candidates for vascular surgery were reviewed. All the arteries in the 200 limbs were visualized and graded as normal, irregular, stenotic, or occluded. The occurrence of hemodynamically significant disease (stenosis or occlusion) was markedly different in various arteries: iliac--37%, common femoral--9%, superficial femoral--58%, deep femoral--19%, popliteal--17.5%, tibialis anterior--27.5%, tibialis posterior--28.5%, and peroneal--16.5%. A remarkable symmetry was observed between the two lower limbs. In 53-76% of contralateral vessels the arteriographic picture was identical. When one degree of difference in arteriosclerotic involvement was allowed, the symmetry increased to 80-96%.

Antithrombosis routines and hemorrhagic complications: a seven year survey comparing vascular and general surgical operations

Prospective monitoring of the occurrence of venous thromboembolism (VTE) and bleeding complications was carried out during a seven year period in a department of general and vascular surgery. Low dose heparin was given by pre-determined criteria to over 1200 patients undergoing general surgical operations, and to almost 700 patients having vascular surgical operations. Over 450 vascular patients received full dose anticoagulation and 3400 patients from both groups received no antithrombotic treatment. Clinically significant major VTE occurred in one percent of all patients. Nine patients died of pulmonary emboli (0.15%). There were 130 patients with bleeding complications (2.2%) half of them severe. Both VTE and bleeding were more common in the vascular patients (1.4 and 3.1% respectively) as compared with general surgery (0.7 and 1.6%). Patients receiving low dose heparin had a 3.4 percent incidence of bleeding but in one half of these cases a technical factor or a breach of the treatment protocol could have contributed to the bleeding. Possible modifications of antithrombosis routines are suggested.