Biomechanical comparison of femoral fixation devices for anterior cruciate ligament reconstruction using a novel testing method.

BACKGROUND: A novel biomechanical test method was implemented to compare the mechanical performance of two femoral fixation anchors (AperFix(r), Cayenne Medical, Scottsdale, AZ, USA or the AppianFx(r), KFx Medical, Carlsbad, CA, USA) that were utilized in anterior cruciate ligament reconstruction. METHODS: Anterior cruciate ligament reconstructions were performed in 20 porcine femurs by using bovine extensor tendon grafts secured with 9 mm femoral anchors (AperFix(r) or AppianFx(r)). 10 specimens were tested for each anchor type. Infrared position sensors determined the repair construct displacements during conditioning (20 cycles at 5-50 N at 0.25 Hz), cyclic loading (1500 cycles at 50-200 N at 1 Hz), and ultimate loading (150 mm/min). Outcomes included tendon elongation, anchor displacement, stiffness, maximum load, yield load, and load at 5mm of anchor displacement. It was hypothesized that there would be no differences in the outcomes of these two devices. Independent measure t-tests compared the performance of the devices (p<0.05). FINDINGS: The performance of the two anchors was comparable during the cyclic loading. During ultimate loading, a statistically higher yield load (p<0.01) and a load at 5mm of anchor displacement (p<0.01) were demonstrated for the AppianFx(r) as compared to AperFix(r). Maximum load and stiffness were not significantly different. INTERPRETATION: Given the good clinical track record of the AperFix(r), the comparable, and in some cases superior, the biomechanical data presented here for the AppianFx(r) are encouraging for their clinical implementation. This study also introduced a novel test method that directly tracks the relevant construct displacements during cyclic and ultimate loading tests of the anterior cruciate ligament reconstructions.

Incidence of new cardiovascular events in patients with and without peripheral arterial disease seen in a vascular surgery clinic.

BACKGROUND: To investigate the incidence of death and of new cardiovascular events at long-term follow-up of patients with and without PAD seen in a vascular surgery clinic. MATERIAL/METHODS: We investigated the incidence of death, new stroke/transient ischemic attack, new myocardial infarction, new coronary revascularization, new carotid endarterectomy, new peripheral arterial disease (PAD) revascularization, or at least one of the above outcomes at long-term follow-up of patients with and without PAD followed in a vascular surgery clinic. RESULTS: At least one of the above outcomes occurred in 259 of 414 patients (63%) with PAD at 33-month follow-up and in 21 of 89 patients (24%) without PAD at 48-month follow-up (p<0.0001). Death occurred in 112 of 414 patients (27%) with PAD and in 10 of 89 patients (11%) without PAD (p=0.002). Stepwise Cox regression analysis for the time to at least one of the 6 outcomes showed that significant independent risk factors were men (hazard ratio =1.394; 95% CI, 1.072-1.813; p=0.013), estimated glomerular filtration rate (hazard ratio =0.992; 95% CI, 0.987-0.997; p=0.003), and PAD (hazard ratio =3.520; 95% CI, 2.196-5.641; p<0.0001). Stepwise Cox regression analysis for the time to death showed that significant independent risk factors were age (hazard ratio =1.024; 95% CI, 1.000-1.049; p=0.048), estimated glomerular filtration rate (hazard ratio =0.985; 95% CI, 0.974-0.996; p=0.007), and PAD (hazard ratio =2.157; 95% CI, 1.118-4.160; p=0.022). CONCLUSIONS: Patients with PAD have a significantly higher incidence of cardiovascular outcomes, especially death, new PAD revascularization, and new carotid endarterectomy, than patients without PAD followed in a vascular surgery clinic.

Prevalence of moderate or severe chronic kidney disease in patients with severe peripheral arterial disease versus mild or moderate peripheral arterial disease.

BACKGROUND: To investigate the prevalence of moderate or severe chronic kidney disease in patients with severe versus mild or moderate peripheral arterial disease. MATERIAL/METHODS: We investigated the prevalence of moderate or severe chronic kidney disease diagnosed as an estimated glomerular filtration rate <60 ml/min/1.73 m2 in 130 patients with severe peripheral arterial disease (ankle-brachial index <0.60) and in 192 patients with mild or moderate peripheral arterial disease (ankle-brachial index 0.60-0.89) seen in a vascular surgery outpatient clinic. RESULTS: An estimated glomerular filtration rate of <30 ml/min/1.73 m2 was present in 51 of 322 patients (16%) with peripheral arterial disease, of 30-59 ml/min/1.73 m2 was present in 172 of 322 patients (53%) with peripheral arterial disease, and of ≥60 ml/min/1.73 m2 was present in 99 of 322 patients (31%) with peripheral arterial disease. An estimated glomerular filtration rate <60 ml/min/1.73 m2 was present in 105 of 130 patients (81%) with an ankle-brachial index <0.60 and in 118 of 192 patients (61%) with an ankle-brachial index of 0.60-0.89 (p<0.001). CONCLUSIONS: The prevalence of moderate or severe chronic kidney disease is high in patients with peripheral arterial disease and is significantly higher (p<0.001) in patients with severe peripheral arterial disease than in patients with mild or moderate peripheral arterial disease.

Live/real time three-dimensional transthoracic echocardiographic assessment of tricuspid valve pathology: incremental value over the two-dimensional technique.

Twenty-nine patients with different tricuspid valve (TV) pathologies were studied by both two-dimensional transthoracic (2DTTE) and live/real time three-dimensional transthoracic echocardiography (3DTTE). A major contribution of 3DTTE over 2DTTE was the en face visualization of all three leaflets of the TV in all patients. This allowed accurate assessment of TV orifice area in patients with TV stenosis and carcinoid disease. Loss of TV leaflet tissue, defects in TV leaflets and size of TV systolic non-coaptation could also be delineated and resulted in identifying the mechanism of tricuspid regurgitation (TR) in patients with Ebstein's anomaly and rheumatic heart disease. Prolapse of TV leaflets could also be well visualized and enabled us to develop a schema for systematic assessment of individual segment prolapse which could help in surgical planning. The exact sites of chordae rupture in patients with flail TV as well as right ventricular papillary muscle rupture could be well seen by 3DTTE. 3DTTE also permitted sectioning of various TV masses for more specific diagnosis of their nature. In addition, color Doppler 3DTTE provided an estimate of quantitative evaluation of TR severity, since the exact shape and size of the vena contracta could be accurately assessed. In conclusion, our preliminary experience with 3DTTE has demonstrated substantial incremental value over 2DTTE in the assessment of various TV pathologies.

Papillary fibroelastoma of the pulmonary valve: assessment by live/real time three-dimensional transthoracic echocardiography.

The differential diagnosis of a cardiac valve mass includes fibroelastoma, myxoma, lipoma, Lambl's excrescences, thrombus, and vegetation. Fibroelastomas are extremely rare primary cardiac tumors. Their incidence is 0.00017-0.033% in autopsy series and 0.019% in clinical series identified on echocardiography. Although rare, fibroelastomas are the most common tumors affecting the cardiac valves with aortic, mitral, tricuspid, and pulmonary valves being involved in this order. In the current report we describe a case of pulmonary valve mass in which a confident prospective diagnosis of fibroelastoma could be made utilizing the technique of three-dimensional transthoracic echocardiography.

Live/real time three-dimensional echocardiographic demonstration of left ventricular noncompaction and thrombi.

We describe two adult patients with left ventricular noncompaction in whom live/real time three-dimensional transthoracic echocardiography (3DTTE) supplemented two-dimensional transthoracic echocardiography in making a definitive diagnosis of clots coexisting with trabeculations in the left ventricle. Mobility of clots and the presence of central echolucencies consistent with clot lysis were best demonstrated by 3DTTE and served to confidently differentiate clots from adjacent trabeculations.

Usefulness of live/real time three-dimensional transthoracic echocardiography in the assessment of atrioventricular septal defects.

We studied nine patients (five newborns and infants, two children, and two adults) with atrioventricular septal defects (four complete, one intermediate, and four partial) utilizing live/real time three-dimensional transthoracic echocardiography (3DTTE) and a 4-MHz matrix array transducer. In all patients, 3DTTE provided additional morphological and/or functional information as compared to standard two-dimensional transthoracic echocardiography (2DTTE). 3DTTE may be a useful supplement to 2DTTE in the assessment of atrioventricular septal defects.

Usefulness of live/real time three-dimensional transthoracic echocardiography in the identification of individual segment/scallop prolapse of the mitral valve.

In this report, we present 34 patients in whom surgical intervention was undertaken for severe mitral insufficiency due to mitral valve prolapse (MVP). Location and severity of MVP and regurgitation were assessed preoperatively by live/real time three-dimensional transthoracic echocardiography and closely agreed with the surgical findings.

Usefulness of live/real time three-dimensional transthoracic echocardiography in the characterization of ventricular septal defects in adults.

In this report, we present 12 patients (range 14-76 years, mean 40 +/- 22.7 years) who underwent surgical repair of a ventricular septal defect (VSD). Location, size, and surrounding anatomy of the VSD were assessed prior to intervention in all patients with live/real time three-dimensional transthoracic echocardiography (3DTTE). In 9 patients, measurements of maximum dimension, circumference, and area by 3DTTE correlated well with the same measurements from intraoperative three-dimensional transesophageal echocardiographic (3DTEE) reconstruction. 3DTTE measurement of maximum dimension of VSDs also agreed well with maximum dimension by surgery in 10 patients. Live/real time 3DTTE accurately defined VSD location, size, and surrounding anatomy in all patients studied by us. VSD characterization by live 3DTTE agreed well with surgery descriptions and 3DTEE measurements.

Live/real time three-dimensional transthoracic echocardiographic assessment of mycotic pseudoaneurysm involving the descending thoracic aorta.

We describe a patient in whom a mycotic aneurysm involving the distal descending thoracic aorta could be definitively diagnosed by live/real time three-dimensional transthoracic echocardiography.

Incremental value of live/real time three-dimensional transthoracic echocardiography in the assessment of left ventricular thrombi.

This is a case series on three adult patients who contain left ventricular (LV) thrombus and the incremental benefits of live/real time three-dimensional transthoracic echocardiography (3DTTE) in comparison to two-dimensional transthoracic echocardiography (2DTTE) in evaluating LV thrombi. These cases illustrate that 3DTTE is of additional benefit by demonstrating the following: (1) cropping of a single 3DTTE apical dataset may be enough to provide comprehensive assessment of the LV in a timely manner even without breath holding in a not fully cooperative patient (2) it identifies the exact point of attachment of the thrombus to the left ventricular wall, (3) helps to delineate the absence or presence of focal echolucent areas within thrombi indicative of the presence and extent of clot lysis, which may have potential therapeutic and prognostic implications, and (4) provides more accurate assessment of thrombus mobility which has prognostic indications.