Breast cancer in Latin America: experts perceptions compared with medical care standards.

BACKGROUND: The BCRF II study presents a systematic review of the norms, recommendations and guidelines that are considered medical care standards (MCS) for breast cancer in 12 Latin American and Caribbean countries. Three key questions from the BCRF I survey data on early detection and diagnosis are presented to identify implementation practice patterns related to MCS. METHODS: Information related to MCS was requested from governmental health authorities, cancer institutes, and national scientific and professional societies in 12 Latin American and Caribbean countries. Documents received were reviewed by breast cancer experts from each respective country. Three key survey questions from the BCRF I survey on early detection and diagnosis were reprocessed to provide information related to implementation practice of existing MCS. RESULTS: All countries included in the BCRF II study had medical care standards (MCS) whether published by governmental authorities, national professional or scientific associations, cancer institutes, or adoption of international MCS. Experts reported different practice patterns at a Country level versus a Center level. Overall, 85% of the experts reported that less than 50% of the women with no symptoms undergo a mammography at the Country level compared to 43% at the Center level. For diagnostic suspicion of breast cancer, 80% of experts considered the diagnostic suspicion at a Country level to come from the patient compared to 50% at a Center level. About 30% of patients waited for more than 3 months for a diagnosis at the Country level compared to 7% at the Center level. CONCLUSION: All the Latin America and Caribbean countries in the study reported the use of similar MCS for breast cancer care. The reported difference between care practiced at a Country level versus a Center level suggests the challenge is not in generating new MCS, but in implementing policies and control mechanisms for compliance with existing MCS, guaranteeing their applicability to all populations.

Femoral pseudoaneurysm from drugs of abuse: ligation or reconstruction?

A plan for management of infected arterial pseudoaneurysm has evolved from our experience with 23 such aneurysms treated between 1981 and 1989 and followed for up to 66 months. Eighteen femoral artery aneurysms are the primary focus of this report. Because we were concerned about the high probability of amputation expected from acute interruption of the femoral artery, we were reluctant to limit initial management to ligation and debridement alone. However, significant complications developed in 12 patients who underwent revascularization, requiring 3 amputations and 13 secondary arterial operations in addition to debridements and skin grafts. In contrast, no amputations were required in six patients who underwent primary arterial ligation and debridement. We recommend primary ligation that controls the septic focus, removes the danger of hemorrhage, and is not accompanied by the threat of secondary arterial infection. After ligation, limb viability is assessed during surgery by presence of an audible Doppler signal at the ankle. Revascularization is considered only when absence of a Doppler signal indicates acute limb ischemia.

Assessment of elastin and collagen contribution to aortic elasticity in conscious dogs.

The elastic behavior of total elastin (EE) and collagen (EC) and the recruitment of collagen fibers (FC) supporting wall stress at a given transmural pressure level were assessed in seven conscious dogs using descending thoracic aortic pressure (microtransducer) and diameter (sonomicrometer) measurements. Stress-strain relationships values calculated at control and during bolus administration of angiotensin and nitroglycerin enabled quantification of angiotensin and nitroglycerin enabled quantification of elastic moduli of elastin (EE = 4.868 +/- 1.753 x 10(6) dyn/cm2; means +/- SD) and collagen (EC = 1,306 +/- 637 x 10(6) dyn/cm2) according to a biphasic model of elastin and collagen parallel arrangement. The FC was found to be 6.1 +/- 2.6% at a pressure level of 118 +/- 16 mmHg. Values for EE and EC were similar to those reported in in vitro studies and showed scarce variability. This approach provides a quantitative evaluation of elastin and collagen moduli in conscious animals and also permits the evaluation of FC, which may be of interest in studies of connective tissue diseases involving the aortic wall.

Paradoxically decreased aortic wall stiffness in response to vitamin D3-induced calcinosis. A biphasic analysis of segmental elastic properties in conscious dogs.

We studied the aortic elastic behavior in response to vitamin D3-induced accelerated calcinosis in conscious dogs chronically instrumented with a pressure microtransducer and a pair of ultrasonic diameter dimension gauges in the upper descending thoracic aorta. The two functional phases of the elastic segmental properties of the aorta in vivo were discriminated by computation on a beat-by-beat basis from the phasic pressure-diameter (P-D) hysteresis loops in basal conditions and during the transient state of a wide range of pressures obtained mechanically (aortic occlusion) or pharmacologically (angiotensin bolus). The overall P-D curve formed by all P-D hysteresis loops was comprised of two linear relations according to a model that assumes that only elastin is stretched at lower pressures, whereas both elastin and collagen are stretched at higher pressures. The slope of the first linear portion of the P-D curve was considered as the elastin P-D elastic modulus, and the slope of the curve obtained by subtraction between the P-D curve and the extrapolation of the elastin straight line was assumed to be the collagen P-D elastic modulus. After vitamin D3-induced calcinosis, the elastin elastic modulus was unaffected, whereas the collagen elastic modulus decreased significantly during occlusion maneuvers (58.6%, p less than 0.01) and during bolus injections of angiotensin (37.2%, p less than 0.05). The collagen elastic modulus correlated with the serum calcium concentration (r = -0.65, p less than 0.001) and with the aortic pulse pressure (r = 0.51, p less than 0.01), and this relation persisted at constant heart rate. Histopathologic analysis evidenced calcium-depositing elastic lamina, focal disappearance of collagen, and rupture of elastic fibers. The present study shows that accelerated, severe, experimental calcinosis-inducing calcium deposition inside the large artery walls is accompanied by a clear-cut paradoxical reduction in arterial rigidity that is mainly due to functional and structural modification of collagen elasticity.

Carotid endarterectomy for asymptomatic carotid stenosis: a ten-year experience with 120 procedures in a fellowship training program.

Performance of carotid endarterectomy for asymptomatic carotid stenosis has been restricted during recent years because of concern of reported complications in as high as 10-15% of patients, as well as limited long-term data on stroke protection. During the last 10 years, we have studied immediate and long-term results of carotid endarterectomy for asymptomatic disease in 120 patients. Operations were performed by a clinical vascular fellow with a staff surgeon in attendance in 113 (94%) cases with the remainder performed by the staff surgeon. Patients' mean age was 66 years; 82% were men. Risk factors included hypertension (56%), smoking (52%), coronary artery disease (32%), diabetes (24%), and hypercholesterolemia (6%). Arteriographic severity of stenoses was 80-99% in 74%, 60-79% in 22%, and 40-59% in 4% of cases. Postoperative complications included two transient neurological events (1.7%). No permanent strokes or deaths occurred. Using the life table method, cumulative stroke rate was 4.5% for ipsilateral events and 7.3% for contralateral events, confirming the high degree of stroke protection afforded by carotid endarterectomy in this population. Since these results were accomplished in a fellowship training program, we regard adequacy of this experience as the most influential factor in accomplishing this record. Surgeons who are unable to achieve comparable results should consider abandonment of the procedure or an extended period of additional training.

Intravascular ultrasonography: validation studies and preliminary intraoperative observations.

Intravascular ultrasonography is emerging as an important imaging modality to assess the presence, distribution, and extent of atherosclerotic vascular disease. To determine the accuracy and clinical utility of intravascular ultrasonography, a flexible catheter-based system was used to generate two-dimensional, cross-sectional vascular images. In 23 arteries of 11 sheep 206 in vivo images demonstrated an echo-free lumen surrounded by three distinct concentric acoustic transitions corresponding to intima, media, and adventitia. Ultrasound measurements of lumen diameter and area correlated significantly with those of corresponding arteriographic measurements obtained by use of digital calipers (r = 0.91, r = 0.86). To evaluate clinical feasibility, intraoperative images (n = 160) were obtained in 10 patients undergoing vascular bypass or hemodialysis access procedures. The images depicted luminal configuration and arterial wall morphologic characteristics. Measurements of lumen diameter and lumen area correlated closely with corresponding intraoperative arteriography (r = 0.81, r = 0.79). The ultrasound images demonstrated arterial stenoses, intimal hyperplasia, intraluminal thrombus, polytetrafluoroethylene graft material, and anastomotic sites. We conclude that flexible catheter-based ultrasonography produces images that accurately demonstrate arterial wall architecture, lumen diameter, and area. Intraoperative application can produce images that provide unique information thus expanding the clinical potential of ultrasonography as a guidance system for vascular procedures.

Reduced dependency on arteriography for penetrating extremity trauma: influence of wound location and noninvasive vascular studies.

Indications for arteriography in penetrating extremity trauma remain controversial. We reviewed our clinical experience in 454 patients (514 extremities) with penetrating trauma admitted during a prior 3 1/2-year period. Injuries were caused by stab wounds in 60 (11.7%) extremities and by gunshot wounds in 454 (88.3%) extremities. Thirty-three of the 60 stab wounds (55%) required urgent exploration, and 27 underwent arteriography. No arteriograms were positive for unsuspected arterial injury in this group. Forty-two of 454 gunshot wounds (9.3%) underwent mandatory exploration; arteriograms were performed on 412 extremities. Forty-four arteriograms (10.7%) demonstrated evidence of unsuspected arterial injuries. During the last year, randomly selected extremities (n = 23) have been studied with B-mode ultrasonography and segmental Doppler pressure measurements. Using the subsequent arteriography as the "gold" standard, sensitivity was 83% and specificity was 100%. Gunshot wounds were categorized according to location and positive arteriograms. Injuries to the lateral thigh and arm resulted in no positive arteriograms, while positive studies were observed in 11% of medial and posterior arm, 14% of antecubital fossa, 25% of forearm, 7.5% of medial and posterior thigh, 8% of popliteal fossa, and 26% of calf injuries. We recommend arteriography for gunshot injuries to identified high-risk areas, while clinical evaluation alone is accurate in all stab wounds to the extremities and gunshot wounds to the lateral thigh and outer arm. Preliminary data suggest expanded use of B-mode ultrasonography may further reduce our dependency on arteriography in these cases.

Effects of muscarinic and beta-adrenergic blockade on the aortic elastic response to epinephrine induced acute hypertension in conscious dogs.

To determine the effects of parasympathetic blockade and beta-blockade on the elastic response of aortic stiffness to vasopressive interventions, we studied 5 unanesthetised adult mongrel dogs by means of a pressure microtransducer and two ultrasonic crystals positioned at opposing sites in the proximal descending thoracic aorta which were used for diameter measurements. Systolic and diastolic changes in pressure and diameter were used to calculate Peterson and incremental elastic moduli. Acute hypertension was induced using infusions of epinephrine during the control period and later propranolol (1.5 mg/kg) plus atropine (0.2 mg/kg). Percent variations of mean aortic diameter were correlated to percent variations in mean aortic pressure in the control period and after autonomic blockade (P less than .001). The slopes of these correlations in the control group were higher than after autonomic blockade (P less than .05). Correlations were also found between Peterson and incremental elastic moduli and mean pressure in the control group and after autonomic blockade (P less than .001). The slopes of the correlations of incremental elastic modulus and Peterson's modulus versus mean aortic pressure were lower in the control group than after blockade (P less than .001). We conclude that in conscious dogs, autonomic blockade with propranolol and atropine decreased the distension and increased the stiffness of the aortic wall in response to acute hypertension mediated by epinephrine.

Penetrating extremity trauma: identification of patients at high-risk requiring arteriography.

Indications for arteriography in patients with penetrating trauma to the extremities remain controversial. Some clinicians have recommended universal use of arteriography, whereas others prefer to rely on physical findings alone. To better define our indications for contrast studies, we reviewed clinical data on 306 patients (349 extremities) with penetrating trauma who were admitted during a prior 2-year period (1985 to 1987). Injuries were caused by stab wounds in 50 (14.3%) extremities and by gunshot wounds in 299 (85.7%) extremities. Twenty-seven of the 50 stab wounds (54%) required urgent exploration based on physical findings, whereas 23 underwent arteriography. None of these studies showed unsuspected arterial injury. Twenty-nine of 299 gunshot wounds (9.7%) underwent mandatory exploration, and arteriograms were performed on 270 extremities; findings in 30 studies (11.1%) were positive for unsuspected arterial injuries. Gunshot wounds were categorized according to location and number of arteriograms with positive results. Arteriograms of lateral thigh and upper arm injuries resulted in no positive outcomes. Positive study results were recorded in 22.9% of calf injuries, 20% of forearm and antecubital injuries, 9.5% of popliteal fossa injuries, 9.0% of medial and posterior thigh injuries, and 8.3% of medial and posterior upper arm injuries. We recommend arteriography for penetrating injuries to these high-risk areas. However, clinical evaluation alone is accurate for identification of arterial trauma with lateral thigh or upper arm wounds and stab wounds to the extremities.

Diagnosis of acute deep venous thrombosis.

This article outlines the application of continuous-wave Doppler, plethysmographic techniques, and B-mode ultrasonography to the diagnosis of suspected deep venous thrombosis in ambulatory patients. Methodology is evaluated, and the diagnostic accuracy and application of these studies are reviewed. The authors' current algorithm for the application of these noninvasive studies also is presented.

Telemetry of aortic pressure in unrestrained animals: validation of the method over a wide range of blood pressure (from 40 to 200 mmHg).

A telemetric method has been designed for continuous measurement of intra-arterial aortic blood pressure in the unrestrained dog. The system used a Konigsberg P7 transducer, a temperature-compensated voltage-controlled oscillator, an FM transmitter, and an FM tuner to convert the signal received into a voltage proportional to aortic blood pressure. The method was validated by comparison with a standard direct method (using cables for transmission). Over a wide range of blood pressure obtained by hypotensive and hypertensive drugs (in total about 2500 data points, ranging from 40 to 200 mmHg), the telemetric method gave almost the same result as the direct method. Absolute error (telemetric measure minus standard measure) was normally distributed, with a mean value of -0.44 mmHg, and a standard deviation of 3.37 mmHg. The telemetric method was designed for future studies on the chronobiology of blood pressure in normal condition, in stress conditions and under drugs.

Dexamethasone attenuates microvascular ischemia-reperfusion injury in the rat cremaster muscle.

We examined the effect of dexamethasone (DXM) pretreatment on microvascular transport of macromolecules in ischemia-reperfusion injury. The rat cremaster muscle was splayed, placed in a Lucite intravital chamber, and suffused with bicarbonate buffer. The clearance of fluorescein isothiocyanate-dextran 150 (FITC-Dx 150) was measured as an index of microvascular transport. After determination of baseline data, the muscle was made ischemic for 2 hr by clamping its vascular pedicle, and subsequently reperfused for 2 hr. Ischemia-reperfusion produced a marked increase in clearance of FITC-Dx 150. After an initial peak of 13 times baseline value clearance fell to approximately 4 times baseline level 30 min into the reperfusion period. Clearance increased slowly throughout the remainder of the experiment, reaching 6 times baseline after 2 hr of reperfusion. The treated animals received DXM 3 hr prior to and immediately preceding the pedicle clamping. DXM reduced macromolecular clearance significantly after the first 30 min of reperfusion, and prevented the increase in clearance over time. After an initial peak, clearance values fell to near twice baseline in DXM-treated animals, and remained at this level for the 2 hr of reperfusion. Our data demonstrate that DXM attenuates the alternations in microvascular macromolecular transport produced by ischemia-reperfusion injury.

End-systolic pressure-volume relationships in dogs during ventilation with PEEP.

Whether left ventricular (LV) contractility changes during ventilation with positive end-expiratory pressure (PEEP) remains controversial. To assess LV inotropic state during PEEP using a load-independent index, we generated end-systolic pressure-volume relationships (ESPVRs) in eight closed-chest, chronically instrumented, anesthetized dogs undergoing 0 [zero end-expiratory pressure for the 1st time (ZEEP1)], 5 (PEEP-5), 10 (PEEP-10), and again 0 (ZEEP2) cmH2O PEEP. LV volume was calculated from three orthogonal internal diameters (sonomicrometry), and LV pressure was measured using an implanted transducer. ESPVRs at each level of PEEP were generated by transient inflation of a vena caval occluder. Despite significant decreases in cardiac output with PEEP-5 (1.81 +/- 0.38 l/min, means +/- SE; P less than 0.05) and PEEP-10 (1.70 +/- 0.46; P less than 0.01) with respect to ZEEP1 (2.12 +/- 0.41), no change was found in the slope (ZEEP1: 6.99 +/- 1.03 mmHg/ml; PEEP-5: 7.48 +/- 1.20; PEEP-10: 7.17 +/- 1.02; ZEEP2: 7.38 +/- 1.02), the volume intercept (ZEEP1: 7.4 +/- 3.4 ml; PEEP-5: 6.6 +/- 3.0; PEEP-10: 7.2 +/- 4.0; ZEEP2: 6.6 +/- 3.6), or the new index area beneath the ESPVR (ZEEP1: 304 +/- 98; PEEP-5: 329 +/- 104; PEEP-10: 310 +/- 98; ZEEP2: 343 +/- 114). We conclude that these levels of PEEP do not affect LV contractility as assessed by the ESPVR.