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PubMed1995

Paraprosthetic regurgitation in aortic prostheses: determination of the hemodynamic significance by pulsed Doppler examination of the subclavian artery flow.

Paraprosthetic leaks in aortic prostheses may cause significant aortic regurgitation. Color flow Doppler echocardiography is the method of choice for detecting paraprosthetic leaks, but quantitation of regurgitation is limited by this method. This study investigated the value of pulsed Doppler of the left subclavian artery flow for assessing the hemodynamic significance of paraprosthetic regurgitation in aortic prostheses in 32 patients with, and in 77 control subjects without paraprosthetic leaks. Paraprosthetic leaks were either detected by transthoracic or transesophageal color flow echocardiography. The hemodynamic significance of paraprosthetic regurgitation was determined by means of a dichotomous angiographic classification - significant versus insignificant regurgitation. Pulsed Doppler was performed to measure the maximal diastolic and systolic velocities, and diastolic and systolic velocity-time-integrals (VTI) and their ratios in the subclavian artery flow. The accuracy of these parameters for differentiating significant versus insignificant regurgitation was assessed. Angiography revealed 13 significant and 19 insignificant forms of aortic regurgitation. In all patients, examination of the subclavian artery was feasible by pulsed Doppler. The highest correlation between Doppler derived parameters and regurgitation was calculated for the ratios of diastolic and systolic VTI (r = 0.84), diastolic VTI (r = 0.82) and ratio of diastolic and systolic velocities (r = 0.80). An increase of the ratio of diastolic and systolic VTI (> 45%) and ratio of diastolic to systolic velocity (> 0.4), and increased diastolic VTI (> 60 cm) in the subclavian artery velocity profile identified significant paraprosthetic regurgitation with a sensitivity of 94%, 75% and 87%, and specificity of 87%, 80% and 87%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Valve Insufficiency↗
PubMed1992

Clinical usefulness of biplane transesophageal echocardiography.

The clinical usefulness of biplane color Doppler transesophageal echocardiography is illustrated by the results obtained in 300 successive examinations. The additional contribution of the newer longitudinal plane was judged significant or major in 64% of the cases. The method was useful mainly for intraoperative examinations, assessment of native valvular disease, prosthetic valve evaluation, search for tumors, and assessment of endocarditis, congenital heart disease, and aortic disease. In contrast, the longitudinal plane option was not contributory in 68% of the cases of thromboembolism. Typically, the technique aided in the evaluation of mitral valve insufficiency and the detection of paraprosthetic leaks. Lesions located at the level of the ascending aorta, the left and right ventricular outflow tracts, and the interatrial septum were also visualized best. The limitations of the method were negligible and the duration of the examination was not significantly increased in comparison to the monoplane method. When available, biplane transesophageal echocardiography seems to be preferred in most clinical settings.

Adolescent↗
PubMed2000

Endoluminal repair of peripheral arterial aneurysms: 4-year experience with the cragg endopro system I.

PURPOSE: To assess the efficiency and long-term patency of the Cragg EndoPro System I in patients with peripheral arterial aneurysms. MATERIALS AND METHODS: In 10 patients, 13 stent-grafts were used to treat 15 arterial aneurysms. Aneurysms were located in the common iliac (n = 4), superficial femoral (n = 4), popliteal (n = 3), and subclavian arteries (n = 2), and in a femoropopliteal bypass-graft (n = 2). Follow-up ranged between 2 and 46 months (mean, 36 months). Examination included clinical status, color-coded duplex sonography, computed tomography angiography, and intra-arterial digital subtraction angiography (DSA). RESULTS: Technical success was achieved in all patients. Primary patency was four of four in iliac vessels and three of nine in non-iliac vessels; secondary patency in noniliac vessels was four of nine. Repairs included one local lysis, four percutaneous transluminal angioplasties, one surgical thrombectomy, and one bypass surgery. Stent wire disintegration was detected in one of four iliac stent-grafts and in seven of nine noniliac stent-grafts. In noniliac grafts, significant stenoses occurred in three of nine; occlusion occurred in five of nine. One complication at the iliac level was a vessel wall penetration at the proximal stent edge, with development of a new aneurysmal formation. No late endoleaks were found. CONCLUSION: Exclusion of peripheral arterial aneurysms with stent-grafts is feasible. Long-term results are excellent in iliac vessels. Mechanical weakness of the stent assembly and frequent re-stenoses or occlusions are significant drawbacks in noniliac vessels with low patency rates.

Adult↗
PubMed1992

Intraoperative echocardiography for diagnosis and treatment of aortic dissection. Utility of color flow mapping for surgical decision making in acute stage.

In the past eight years until July 1992, 92 patients were admitted in the acute state of aortic dissection within two weeks from the onset of symptoms. 41 were diagnosed as Stanford type A and 51 were type B by transthoracic and transesophageal echography, computer tomography, and surgery. Sensitivity of transesophageal echography to detect the intimal flap and the false lumen was 97.6% in patients with Stanford type A and 100% in patients with Stanford type B. The surgical decision making has been mostly depending on the transesophageal echographic diagnosis. When the intimal flap was detected in the ascending aorta (Stanford type A) surgery was performed in emergency regardless of any evidence of rupture, cardiac tamponade, and severe aortic regurgitation. When the aortic dissection was detected only in the descending aorta (Stanford type B) the main course of therapeutic strategy in our institute was medical treatment. Surgery was performed on 37 patients of type A and nine patients of type B with mortality of 18.9% and 55.5% respectively. Four patients of type A and 42 patients of type B were treated medically with a mortality of 75.0% and 2.2% respectively. The relatively large leakages from the anastomosis of the aortic clamp site were repaired secondarily in two patients, and fenestration of the superior mesenteric artery was performed on one patient due to ischemia of the small intestine depending on the intraoperative direct scanning of color flow mapping. Coronary artery involvement of dissection was strongly suspected in two patients by intraoperative transesophageal echography and aortocoronary bypass grafting was performed on these patients. Perfusion problems was encountered in five of 37 patients with type A aortic dissection (13.5%) during cardiopulmonary bypass. Intraoperative transesophageal echography could clearly detect the hemodynamic changes in the descending aorta resulting from inadequate perfusion which was useful for the management of perfusion control during cardiopulmonary bypass. Secondary repair of the aortic arch was required due to ischemia of the aortic arch vessels in two patients after the primary surgery. The extension of the dissection into the aortic arch vessels can be promptly diagnosed with the combination of transesophageal echography and transcutaneous echography. In conclusion, transesophageal Doppler echography is the most rapid diagnostic tool for decision making in acute aortic dissection, and intraoperative transesophageal echo can provide useful information to resolve the perfusion difficulties during cardiopulmonary bypass.(ABSTRACT TRUNCATED AT 400 WORDS)

Acute Disease↗
PubMed1989

Doppler echocardiographic evaluation of tilting-disc prosthetic heart valves in children.

To determine the Doppler characteristics of tilting-disc prosthetic heart valves in children, 22 children with mitral prostheses were studied 8 +/- 2 months after surgery, and 10 children with aortic prostheses were studied 37 +/- 26 months after surgery. All valves were thought to be functioning normally by clinical examination. Valve competence was interrogated and peak and mean velocities were measured by standard pulsed wave, continuous wave and color Doppler techniques. Prosthetic valve area was calculated and compared to the known valve area. Mild prosthetic valve regurgitation was present in 8 of 22 mitral and 7 of 10 aortic prostheses. For mitral prostheses, peak velocity was 192 +/- 41 cm/s, mean velocity was 118 +/- 37 cm/s and mean gradient was 7 +/- 4 mm Hg. For aortic prostheses, peak velocity was 287 +/- 88 cm/s, mean velocity was 197 +/- 59 cm/s, peak gradient was 36 +/- 21 mm Hg and mean gradient was 19 +/- 11 mm Hg. Prosthetic mitral valve area, calculated by the pressure half-time and modified Gorlin methods, correlated well with the known valve area (r = 0.89, standard error of the estimate = 0.29 and r = 0.95, standard error of the estimate = 0.21, respectively). Prosthetic aortic valve area, calculated by the modified Gorlin method, correlated well with the known valve area (r = 0.89, standard error of the estimate = 0.18). Residual valvular abnormalities are common after prosthetic valve insertion in children. Doppler estimates of prosthetic valve area correlate well with the known valve area but have a large standard error of the estimate.

Aortic Valve↗
PubMed2003

Percutaneous treatment of long superficial femoral artery occlusive disease: efficacy of the Hemobahn stent-graft.

PURPOSE: To assess the efficacy of the Hemobahn stent-graft in the percutaneous treatment of long occlusive lesions of the superficial femoral artery (SFA). METHODS: Fifty-nine limbs in 54 patients (42 men; mean age 73.3+/-8.2 years, range 55.2-91.3) with 59 symptomatic SFA occlusions >10 cm in length were selected for percutaneous treatment with the Hemobahn stent-graft. The treated SFA was assessed for patency and degree of stenosis by color-flow duplex ultrasound prior to discharge and at 1, 3, and 6 months and yearly thereafter. The actuarial life-table method was used to derive primary and secondary patency rates. RESULTS: Primary technical success was achieved in 56 (95%) of 59 limbs on an intention-to-treat basis (2 access and 1 device failures). In the first 30 days, 4 (6.8%) stent-graft thromboses and 5 (8.5%) minor technical difficulties occurred. Up to 1 year, there were 15 (25.4%) primary occlusions, 7 (11.9%) of which were associated with restenosis. Cumulative primary patencies were 88%, 67%, and 58% at 1, 6, and 12 months, respectively; secondary patencies were 92%, 82%, and 73% at the same intervals. There was no statistically significant difference (p<0.05) in patency (primary or secondary) with respect to presenting symptoms, lesion length, stent-graft length, or distal runoff. CONCLUSIONS: Symptomatic long occlusive lesions of the SFA treated percutaneously with the Hemobahn stent-graft achieved good outcomes initially with a low complication rate. Primary and secondary patencies were similar to those reported for open synthetic femoropopliteal bypass procedures.

Aged↗
PubMed2000

Clinical performance and periodontal outcome of temporary crowns and fixed partial dentures: A randomized clinical trial.

STATEMENT OF PROBLEM: Different materials (autopolymerizing, dual curing, and light initiated) are used for fabricating provisional restorations during prosthetic treatment. Randomized clinical trials that have evaluated these provisional materials have not been published. PURPOSE: This clinical trial compared the handling, fitting, plaque adherence, gingivitis, color stability, and the subjective assessment of the provisional materials by the patient and the dentist for 2 autopolymerizing (Protemp, Luxatemp), 1 dual-curing (Provipont), and 1 light-initiated (Triad-VLC) material for the manufacturing of temporary crowns and fixed partial dentures. MATERIAL AND METHODS: Thirty subjects in need of 2 similar fixed prosthetic restorations (single crowns ¿20, three-quarter crowns ¿2, connected crowns ¿9, or fixed partial dentures ¿30) were treated with 1 temporary restoration of Protemp II (control) and one randomly selected from Luxatemp, Provipont, or Triad-VLC materials. The mean time of treatment was 37.5 days (minimum 2 days, maximum 156 days). All restorations were manufactured intraorally with a vacuum-formed template. RESULTS: Mechanical and retentive characteristics revealed a high level of clinical reliability. Plaque adherence of the teeth with temporary restorations was significantly increased (P =.0039) compared with the untreated mesial reference teeth. CONCLUSION: The advantageous mechanical properties of the light-curing and dual-curing materials reviewed in dental literature were clinically offset by disadvantages in handling.

Chi-Square Distribution↗
PubMed2000

Colour Doppler diagnosis of perigraft flow following endovascular repair of abdominal aortic aneurysm.

BACKGROUND: Endovascular repair of abdominal aortic aneurysm is a relatively new surgical technique which is less invasive than conventional open abdominal surgery but is associated with a significant specific complication of endoleak. The aim of this study was to determine the accuracy of duplex ultrasound imaging, utilising colour Doppler, as the primary method for post surgical monitoring of endovascular aneurysm repair. METHODS EXPERIMENTAL DESIGN: a case cohort study of 45 patients undergoing endovascular repair of abdominal aortic aneurysm. SETTING: angiography, CT scanning and surgery performed at Westmead Hospital, a teaching hospital of the University of Sydney; patients followed postoperatively at the Westmead Vascular Laboratory, a dedicated vascular diagnostic ultrasound facility. PATIENTS: Forty males and five females, mean age 69.1 years (range 51 to 84). INTERVENTIONS: patients underwent attempted insertion of an EVT (endovascular prosthesis) for exclusion of abdominal aortic aneurysm (mean diameter 5.3 cm; range 4.0 to 8.4 cm). Conversion to open repair was required in three cases (6.6%). An aorto-biliac graft was inserted in 28 patients, a tube graft in eight and an aorto-unilateral iliac graft with femorofemoral (or ilioilial) crossover graft in six. MEASURES: patients were followed over a period of 53 months (median follow-up time 15 months) with 106 colour Doppler scans of 39 endovascular grafts (mean of 2.9 scans per patient). RESULTS: All aneurysms decreased in diameter (range 0.1 cm to 4.3 cm, mean 0.9 cm). Abnormal flow in the residual aneurysmal sac was found in three patients. In all three cases of endoleak the colour Doppler diagnosis was supported by CT scan and confirmed on angiography. The CT scans did not provide any additional information to that obtained by colour Doppler imaging. CONCLUSIONS: Colour Doppler provides an effective means of non-invasive follow-up assessment of patients who have had endovascular repair of abdominal aortic aneurysms.

Aged↗
PubMed1992

Intraoperative transesophageal echocardiography for the evaluation of mitral, aortic and tricuspid valve repair. A tool to optimize surgical outcome.

The present study reviews the clinical applicability and usefulness of intraoperative transesophageal echocardiography (TEE) during valve repair. Intraoperative TEE was performed in 48 consecutive patients, who were divided into three groups: 1. mitral valve repair (MVR), 2. aortic valve repair (AVR), 3. tricuspid valve repair (TVR). Residual valve regurgitation was assessed by color Doppler echocardiography on a scale from 0 to 4. The ratios of the jet area (JA) to the left- and right-atrial areas (JA/LAA and JA/RAA) were analyzed before and after cardiopulmonary bypass (CPB). In group 1, 14 patients were scheduled for MVR, of which 4 patients underwent valve replacement and 10 MVR. Post-repair TEE studies showed a significant decrease of mitral regurgitation. In 2 of the 10 patients, TEE demonstrated severe residual regurgitation requiring valve replacement during the same thoracotomy. In group 2, 11 patients underwent aortic commissurotomy. Post-repair TEE showed an increase in the systolic opening diameter and opening area of the aortic valve. One patient underwent valve substitution because of severe aortic regurgitation. In group 3, 23 patients were scheduled for TVR. In 3 of them TEE showed no significant regurgitation thus rendering tricuspid valve surgery unnecessary. Twenty patients underwent TVR of whom two showed unacceptable post-repair regurgitation requiring further surgery. Eighteen patients showed a significant reduction of valve regurgitation after TVR, and a further reduction was achieved by adjusting the tricuspid annuloplasty under TEE guidance.

Adult↗
PubMed2001

Glass fiber-reinforced abutments for dental implants. A pilot study.

Titanium abutments in dental implants shine through all-ceramic crowns and therefore limit excellent esthetic results. Prototypes of tooth-colored fiber-reinforced abutments were investigated to avoid the shining-through effect. In vitro, the fracture strength was determined after thermal cycling and mechanical loading of all-ceramic single crowns and four-unit bridges made of a fiber-reinforced composite. The suprastructures were adhesively fixed onto fiber-reinforced implant abutments and compared with those fixed on standard titanium abutments. The median of the fracture strength of the titanium-supported all-ceramic crowns was significantly higher than the median of crowns fixed onto the prototypes. But this value was still more than twice as high as the maximum loading force under oral conditions. No statistical difference was found between four-unit bridges made by fiber-reinforced composite inserted onto titanium abutments and those inserted onto fiber-reinforced abutments. Fiber-reinforced abutment prototypes for dental implants avoided the shining-through effect associated with metal abutments. Their load-bearing capacity after in vitro stress simulation was higher than the maximum oral loading force. With some improvements, the fiber-reinforced implant abutments are therefore a promising alternative to titanium abutments.

Composite Resins↗
PubMed1993

Evaluation of bioprosthetic valve-associated thrombus in ventricular assist device patients.

BACKGROUND: Thromboembolic events may be related to thrombotic deposition on prosthetic valves. In a left ventricular assist device (LVAD) that contains two porcine pericardial bioprosthetic valves in addition to significant associated biomaterial placement, this may be particularly true. Thrombotic deposits on valves removed from LVADs at autopsy or heart transplantation were scored to determine (1) the nature and location of valvular deposition, (2) whether deposition was related to thromboembolic events, (3) correlations between deposition and patient hemodynamic and coagulation parameters, and (4) implant time dependency. METHODS AND RESULTS: Novacor LVADs were implanted in 23 patients as a bridge to transplantation for 1 to 303 days. Photographs of the concave (downstream) and convex (upstream) side of the inflow and outflow valve were made at explant and later scored for (1) total thrombus area (10 = equivalent of cusp area), (2) percent of cusp area occupied by solid thrombus, (3) thrombus color (10 = dark red, 0 = white), and (4) average percent of valve strut height involved with thrombus (from a side view). The inflow valve was shown to have heavier and redder deposition than the outflow valve. This was also true for the concave versus the convex side. Heaviest deposition was seen on the inflow valve concave side, which rests within the LVAD pumping sac and may be subject to poor convection. Patients with neurological thromboembolic events (8/23) during implantation had heavier deposition on the inflow valve concave side (5.7 +/- 2.7 versus 4.6 +/- 2.2, P < .05). Pump volumetric output was also found to negatively correlate with thrombus area on this valve and side (r = -.61, P = .002). Platelet release (platelet factor 4) was correlated with thrombus involvement on the upstream (convex) side of the inflow valve (r = .82, P = .002). No significant dependence of deposition on the implant time was found. CONCLUSIONS: Valve thrombus deposition was related to thromboembolic events. Pump volumetric output and platelet release were found to be related to deposition. These results may have implications for the role of hemodynamics and platelet activation in thromboembolism associated with prosthetic valve placement in general.

Bioprosthesis↗
PubMedDate not supplied

Structural evaluation of porcine heart valve prostheses with radiofrequency ultrasound.

BACKGROUND: Bioprosthetic heart valve use is limited by progressive degeneration. Early degenerative changes are often occult, making assessment of tissue integrity difficult. Ultrasound tissue characterization may detect alterations in tissue structure and allow early detection of leaflet degeneration. METHODS: Using a modified echocardiographic unit (Acuson), radiofrequency (RF) integrated backscatter amplitude (IBA) (integral/RF/dt) was measured in 38 leaflets from nine explanted and six control porcine valves. Regions of interest in each leaflet were studied using four ultrasound frequencies. Radiographic gray scale mean and leaflet thickness were measured at each region of interest. Percent collagen and mineral were calculated for each region of interest using color-image processing of histologic sections and compared to IBA. RESULTS: IBA values for control vs. explanted leaflets were (mean value+/-standard deviation): 8.2+/-4.69 dB vs. -4.7+/-4.64 dB at 7.0 MHz; -5.8+/-4.34 dB vs. -3.1+/-5.34 dB at 5.0 MHz; -3.8+/-3.38 dB vs. -2.1+/-3.18 dB at 3.5 MHz; and -9.0+/-4.58 dB vs. -7.1+/-4.25 dB at 2.5 MHz. Collagen content was 27.7+/-8.50% vs. 33.2+/-10.90%, mineral content was 0.1+/-0.10% vs. 2.1+/-4.30%, and radiographic gray scale mean was 150.6+/-1.96 vs. 145.3+/-5.14 for control vs. explanted leaflets, respectively. For control and explanted leaflets IBA, collagen content, mineral content, and radiographic gray scale mean were different (control vs. explanted P<0.05). Leaflet thickness was also noted to be different between the two groups. IBA was different among explanted leaflets with low, medium, and high mineral content. CONCLUSION: IBA was found to be a useful technique to differentiate normal from explanted porcine prosthetic valves in vitro. This method may be useful in the serial assessment of bioprosthetic leaflet degenerative properties in vivo.

Adult↗
PubMed1999

The quadrileaflet mitral valve: follow-up in rheumatic heart disease.

This prospective study evaluated the clinical performance of a novel stentless quadrileaflet bovine pericardial mitral valve implanted at one center since December 1996. After giving informed consent, patients were included in the study if they required isolated mitral valve replacement. All underwent comprehensive clinical evaluation, as well as transthoracic M-mode, two-dimensional and Doppler (pulsed, continuous, and color) echocardiography preoperatively and postoperatively at 1 month, 3 months, and annually thereafter. Mitral valve area was derived by planimetry, the pressure half-time method, and the continuity equation. The degree of mitral regurgitation was semi-quantitated using color Doppler. In all 38 patients with rheumatic valvular heart disease (mean age 35+/-13 years) were monitored for 13.8+/-7.5 months (range, 1 to 29 months). All but three patients are alive and symptomatically improved (functional New York Heart Association class I or II). One valve was explanted because of early prosthetic valve endocarditis. There were no episodes of thromboembolism or anticoagulation-related hemorrhage. Left ventricular function was maintained with increased cardiac output and low transmitral pressure gradients. The mitral valve area was larger when measured by pressure half-time and planimetry than by the continuity equation (P<.05). In an independent clinical evaluation of a subset of 30 patients, mitral stenosis was considered absent in 33%, mild in 30%, mild to moderate in 26%, and moderate in 10% of cases. No or less than or equal to mild mitral regurgitation was noted in the majority of patients postoperatively, both clinically and echocardiographically. We are encouraged by the clinical performance of the quadrileaflet mitral valve and with patient outcome. Long-term follow-up data are needed to assess durability.

Adult↗
PubMedDate not supplied

Assessment of normal and abnormal prosthetic mitral valves by Doppler echocardiography. Doppler in prosthetic mitral valves.

Pulsed, continuous-wave, and color Doppler were performed in 165 normal mitral prostheses and 58 patients with prosthetic dysfunction (46 regurgitant and 12 obstructive valves) proved by catheterization and/or surgery. Mean mitral gradient (MG) and pressure half-time (PHT) were determined in all cases. Among normal prostheses, a wide range of both MG and PHT was observed in each type of valve and a considerable overlap between valves of different size. St-Jude's valve had the most optimal hemodynamics. Mild mitral insufficiency was detected in 14% of tissue and 24% of mechanical mitral valves. Repeat studies were performed in 30 patients over a 2.4 years period. Nine patients developed Doppler evidence of new prosthetic dysfunction, while Doppler parameters remained unchanged in 21 patients during the follow-up period. Among malfunctioning valves, Doppler correctly identified all cases of prosthetic obstruction (n = 12), and 42 of 46 regurgitant valves. We conclude that Doppler echocardiography is a very useful technique in both non-invasive assessment and follow-up of normal prosthetic valves in the mitral position and in detecting prosthetic dysfunction, especially when prosthetic obstruction is present.

Adolescent↗
PubMed1992

Early evidence of beneficial effects of chordal preservation in mitral valve replacement on left ventricular dimensions.

Earlier authors have shown the improved left ventricular (LV) function after chordae-preserving mitral valve replacement (MVR) in follow-up studies. Seventy-nine consecutive patients undergoing MVR were studied preoperatively and pre-discharge with M-mode and two-dimensional Color Doppler echocardiography for early LV morphometric changes. Conventional MVR was performed in 42 patients (Group 1) and the posterior leaflet-chordae-papillary muscle complex was preserved in 37 patients (Group 2). Both cohorts were similar in age, sex, preoperative NYHA class and valve pathology. Four St. Jude bioprostheses, 9 Medtronic and 66 Sorin prostheses were implanted. The intraoperative and perioperative management protocol was uniform for both groups. The median left atrial dimension in both groups decreased to better physiological levels (53 to 46 mm in group 1, 52.5 to 46 mm in group 2). The median LV enddiastolic dimension increased from 47 to 48 mm in group 1 while it decreased from 56.5 to 49 min in group 2. The median LV endsystolic dimension remained unchanged in group 1 but decreased in group 2 (37.6 to 36 mm). Echocardiographic documentation of such early changes in the LV dimensions after modified MVR indicates that the beneficial effects of chordal preservation become evident early in the postoperative period and may explain the improved perioperative LV function after modified MVR compared to conventional MVR.

Adolescent↗
PubMed1993

Vascular ultrasonography for deep venous thrombosis after total knee arthroplasty.

Screening vascular ultrasonography was performed postoperatively on 164 consecutive patients being treated with total knee arthroplasty (203 total knee prostheses). This consisted of examination of the femoral and popliteal veins of the operative extremity with color flow and duplex ultrasonography one week postoperatively. All patients received deep venous thrombosis (DVT) prophylaxis with sequential compressive pneumatic stockings, low-dose warfarin, continuous passive motion, and early mobilization. All patients were observed prospectively for thromboembolic sequelae for a minimum of six months postoperatively. The screening study was significantly limited in six (3%) of the 203 total knee prostheses. The overall incidence of sonographically detected proximal DVT or symptomatic calf vein thrombosis was 3% (6/203), and the incidence of symptomatic pulmonary embolism was 2% (4/203). Four of the ten thromboembolic complications occurred after hospital discharge. Results of this study suggest that duplex ultrasonography can be a useful screening method for identification of venous thrombosis after TKA. Patients with asymptomatic proximal DVT can be identified and appropriately treated before development of serious thromboembolic complications. Routine screening for DVT after TKA can avoid the considerable expense, inconvenience, and potential risk of complications associated with prolonged postoperative prophylactic anticoagulation. The combination of sequential compressive stockings, early mobilization, and low-dose warfarin appears to be a safe and effective prophylactic regimen against venous thromboembolic disease in these high-risk patients.

Adult↗
PubMed1992

Regurgitant flow in cardiac valve prostheses: diagnostic value of gradient echo nuclear magnetic resonance imaging in reference to transesophageal two-dimensional color Doppler echocardiography.

Gradient echo nuclear magnetic resonance (NMR) imaging and transesophageal two-dimensional color Doppler echocardiography are flow-sensitive techniques that have been used in the diagnosis and grading of valvular regurgitation. To define the diagnostic value of gradient echo NMR imaging in the detection of regurgitant flow in cardiac valve prostheses and the differentiation of physiologic leakage flow from pathologic transvalvular or paravalvular leakage flow, 47 patients with 55 valve prostheses were examined. Color Doppler transesophageal echocardiography was used for comparison. Surgical confirmation of findings was obtained in 11 patients with 13 valve prostheses. Gradient echo NMR imaging showed regurgitant flow in 37 of 43 valves with a jet seen on transesophageal echocardiography and it detected physiologic leakage flow in 4 additional valves. There was 96% agreement between the two methods in distinguishing between physiologic and pathologic leakage flow. The methods differed on jet origin of pathologic leakage flow in six prostheses. The degree of regurgitation was graded by both NMR imaging and transesophageal echocardiography, according to the area of the regurgitant jet visualized; gradings were identical for 75% of valve prostheses. Quantification of jet length and area showed a good correlation between the two methods (r = 0.85 and r = 0.91, respectively). Gradient echo NMR imaging is a useful noninvasive technique for the detection, localization and estimation of regurgitant flow in cardiac valve prostheses. However, because transesophageal echocardiography is less time-consuming and less expensive, gradient echo NMR imaging is unlikely to displace transesophageal echocardiography and should be used only in the occasional patient who cannot be adequately imaged by echocardiography.

Coronary Circulation↗
PubMed2006

Ventricular septal defect closure in right coronary cusp prolapse and aortic regurgitation complicating VSD in the outlet septum: which treatment is most appropriate?

BACKGROUND: There is currently not a standardized technique for the sizing and shaping of surgical closure of the ventricular septal defect (VSD) patch in patients with right coronary aortic cusp prolapse and aortic regurgitation (AR) complicating VSD in the outlet septum. METHODS: Forty-six VSD patients who had aortic valve prolapse were divided into groups DC (direct closure, n=19), and SPC (small patch closure, n=27). Preoperative and postoperative echocardiography with Doppler color flow interrogation was performed on all patients. RESULTS: In the DC group, among seven patients who had aortic valve prolapse but no AR preoperative, one patient developed AR during postoperative follow-up period. In the remaining 12 patients who had mild AR associated with aortic valve prolapse prior to the procedure, AR was diminished in four and unchanged in six patients. However, AR was aggravated in two patients who required further operations for AV repair or replacement. In the SPC group, among the eight patients who had no preoperative AR, AR progressed in one patient postoperatively. In the remaining 19 patients who had mild AR, AR was diminished in 15 and unchanged in four. The outcome from the operative procedure was significantly better in the SPC group than DC group with mild preoperative AR (chi(2)=7.82; P<0.05). CONCLUSIONS: Small patch closure for this type of VSD is safer and more reliable in improving mild AR than that of direct closure, especially in patients with mild AR.

Adolescent↗