Idiopathic perforation of a porcine aortic bioprosthesis in the aortic position

The report of a failure of glutaraldehyde-preserved porcine aortic xenograft bioprosthesis in the aortic position after 13 months is presented. Severe aortic regurgitation resulted from three "idiopathic" perforations in one of the cusps, and a linear tear in another cusp. Light and electron microscopy showed generalized degeneration of collagen thoughout the faulty valve. The absence of a platelet-fibrin coat on edges of the tear suggested a recent origin, compatible with cardiac catheter manipulation during unsuccessful attempts to cross the valve. The histopathologic data from this valve correlate with previously reported failures with formaldehyde preserved xenograft valves.     

Effects of dobutamine on aortic valve indexes in asymptomatic patients with bileaflet mechanical prostheses in the aortic valve position

We investigated the effects of alternating transvalvular flow rate on Doppler-derived aortic valve resistance and valve area in asymptomatic patients with mechanical aortic valve replacement under dobutamine infusion. The Gorlin-derived aortic valve area and continuity equation-derived aortic valve area seem to be less flow dependent; valve resistance tends to be flow dependent.     

Echocardiogram of the porcine aortic bioprosthesis in the mitral position

The sera from 48 female rabbits immunized by a series of multiple intradermal injections of washed epididymal, washed ejaculated, and beta-amylase-treated rabbit spermatozoa in complete adjuvant were examined for spermagglutinins by the Kibrick gel agglutination test and a slight modification of the Shulman capillary agglutination test. Control animals receiving the adjuvant or saline usually had no positive titers. All three antigenic preparations produced similar titers, positive at dilutions as high as 8192-fold with Kibrick test and 256-fold with the Shulman test. Maximal titer development was reached 4 to 6 weeks after starting the immunization, and positive sera were obtained from some does for 25 weeks. The correlation coefficients between positive titers obtained by the two tests were r = 0.91 during the first 10 weeks and 0.41 at 15 to 25 weeks after immunization.     

Stenosis of Carpentier-Edwards pericardial bioprosthesis in the tricuspid position caused by adhesion of native valve cusps to the bioprosthesis

We experienced a case of dysfunction of Carpentier-Edwards pericardial bioprosthesis in the tricuspid position. Explanted bioprosthesis showed overgrowth of neointima from ring to cusps and adhesion to remnants of native cusps. This restricted the motion of the pericardial leaflets resulting in orifice stenosis. Care must be taken in such valve replacement by this prosthesis leaving native valve tissue.     

Clinical factors useful in predicting aortic valve structure in patients > 40 years of age with isolated valvular aortic stenosis

A number of reports have described the frequency of coronary arterial narrowing in patients with valvular aortic stenosis. No published reports have examined the structure of the stenotic aortic valve in adults and related the valve structure to variables, including coronary arterial narrowing, useful in predicting that structure. One hundred eighty-eight patients having aortic valve replacement for isolated valvular aortic stenosis were studied. All patients were > 40 years of age at the time of aortic valve replacement, all had coronary angiograms preoperatively, and of 182 patients (97%) measurements of serum total cholesterol had been obtained and 184 (98%) had body mass index calculated. The structure of the operatively excised valve was classified as unicuspid or bicuspid (congenitally malformed), or tricuspid aortic valve. A logistic regression model was developed that found 4 factors (age, serum total cholesterol, angiographic coronary artery disease and body mass index) to be predictive of aortic valve structure: (1) Patients with at least 3 or all 4 factors high or present (i.e., age > 65 years, serum total cholesterol > 200 mg/dl, body mass index > 29 kg/m2 and coronary artery disease) had a low probability (10 to 29%) of having a congenitally malformed valve; (2) patients with at least 3 or all 4 factors low or absent (i.e., age < or = 65 years, serum total cholesterol < or = 200 mg/dl, body mass index < or = 29 kg/m2, and no coronary artery disease) had a high probability (72 to 90%) of having a congenitally malformed valve.(ABSTRACT TRUNCATED AT 250 WORDS)     

Prognosis after valve replacement in patients with severe aortic stenosis and a low transvalvular pressure gradient

OBJECTIVES: This study was conducted to determine the risks and benefits of valve replacement in patients with severe aortic stenosis and a low transvalvular pressure gradient. BACKGROUND: There is uncertainty regarding the appropriate management of adults with severe aortic stenosis and a transvalvular pressure gradient < or = 30 mm Hg. With only six such patients reported, one study suggested that these subjects have a prohibitive operative risk and little symptomatic improvement if they survive surgical treatment, whereas another showed that they can survive an operation and improve symptomatically. METHODS: In an attempt to clarify the risks and benefits of valve replacement in these patients, we reviewed the records of 18 patients (15 men and 3 women, aged 49 to 81 years) with severe aortic stenosis (valve area < or = 0.4 cm2/m2 body surface area), a mean transvalvular pressure gradient < or = 30 mm Hg and limiting symptoms (New York Heart Association functional class III or IV) who underwent valve replacement. RESULTS: Six patients (33%) (95% confidence interval 13% to 59%) died perioperatively, whereas 10 patients (56%) (95% confidence interval 31% to 78%) improved symptomatically to functional class I (n = 8) or II (n = 2) (p = NS in comparison with the 6 who died). No clinical or hemodynamic variable was predictive of survival or improvement in functional class. CONCLUSIONS: Valve replacement in patients with severe aortic stenosis and a transvalvular pressure gradient < or = 30 mm Hg is accompanied by a considerable operative risk. Although there were no significant differences in this small series between the fraction of patients who died and those who exhibited improvement, we still recommend the procedure because many patients survive the operation and most of the survivors show an improved symptomatic status.     

Reoperation for mitral regurgitation 13 years after aortic valve replacement and manouguian's anulus enlargement: report of a case

The patient was 22-year-old female. She had undergone aortic valve replacement and Manouguian's anulus enlargement with low porosity woven Dacron patch for congenital aortic stenosis 13 years ago, and developed mitral regurgitation 9 years after that operation. Two regurgitant flow were observed. One was originated from the orifice due to mitral prolapse. The other was from a tear in the anterior leaflet. It was around the tip of the prosthetic patch, approximately 7 mm in size, and was repaired easily. But the mitral valve itself was found to be malformed and prolapsed, requiring mitral valve replacement. Her postoperative course was uneventful.     

Reversibility of cardiac dysfunction after valve replacement in elderly patients with severe aortic stenosis

BACKGROUND: The role of aortic valve replacement for aortic stenosis has not been fully defined in terms of the postoperative reversibility of cardiac dysfunction and pulmonary hypertension in elderly patients. METHODS: Cardiac function, assessed by radioisotope ventriculography and catheterization data, was evaluated before and after operation, and their results were compared between preoperative and postoperative data in each group of younger patients (<69 years, group I, n = 29) and elderly patients (> or =70 years, group II, n = 21). RESULTS: One month postoperatively the peak ejection rate determined by radioisotope ventriculography improved significantly in comparison with the preoperative value in elderly patients (preoperatively, 228 +/- 38 versus postoperatively, 319 +/- 116% end-diastolic volume per second, p < 0.05), although their preoperative peak ejection rate was severely depressed. The postoperative peak filling rate of the elderly group was not completely reversible to almost normal value, whereas that of the younger group was completely reversible. Early diastolic peak filling rate (one-third peak filling rate) was not reversible in both two groups. Pulmonary hypertension in the elderly patients was reversible to postoperative almost normal pulmonary artery pressure despite the severity of aortic stenosis (systolic pulmonary artery pressure preoperatively, 37 +/- 16 mm Hg versus postoperatively, 25 +/- 5 mm Hg, p < 0.02; diastolic pulmonary artery pressure preoperatively, 15 +/- 6 mm Hg versus postoperatively, 10 +/- 4 mm Hg, p < 0.05). CONCLUSIONS: Both cardiac dysfunction, reflected by reduction of peak ejection rate, and pulmonary hypertension in elderly patients with severe aortic stenosis were reversed, reaching almost normal values 1 month after operation.     

The Geriatric Concentration Test. Results of a study of patients over 65 years of age in Mannheim

In a clinical trial, the influence of repeated intermittent prone position on pulmonary gas exchange was investigated in 6 patients with severe ARDS. Despite various intra- and interindividual differences, oxygenation index (calculated by the paO2:FiO2 ratio) was improved significantly by change from supine to prone position in the first two days of treatment, whereas paCO2 remained unchanged. Later on, a significant improvement of oxygenation could not be verified. In patients with proven or presumed densities of dorsal lung regions, body position changes from supine to prone position in the early phase of treatment may improve arterial oxygenation and may be regarded as a therapeutic principle in conventional ARDS treatment.     

The surgical treatment of traumatic rupture of the aortic valve: report of a case after blunt chest trauma

An elderly patient with traumatic aortic valvular insufficiency was treated surgically with valve replacement, the preferred method of treatment, since prognosis is poor without timely surgical therapy. Further emphasis should be given to early diagnosis of this lesion.     

Treatment of the aortic valve and ascending aorta. The significance of reconstructive methods on the aortic root

BACKGROUND AND OBJECTIVE: The standard surgical repair of disease of the aortic valve and the ascending aorta has been combined replacement, which includes the disadvantage of inserting a mechanical valve. We have investigated an individualized approach which preserves the native valve. PATIENTS AND METHODS: Between October 1995 and October 1997, a consecutive total of 101 patients (72 men, 29 women, aged 21-83 years) underwent operations for disease of the ascending aorta: aortic dissection type A in 34 patients, aneurysmal dilatation in 67. Dilatation of the aortic arch was associated with aortic regurgitation in 58 patients. There were 11 patients with aortic valve stenosis or previously implanted aortic valve prosthesis among a total of 46 whose aortic valve was replaced (group II). Supracommissural aortic replacement with a Dacron tube was performed in 16 patients (group I) with normal valve cusps and an aortic root diameter < 3.5 cm. In 28 patients with an aortic root diameter of 3.5-5.0 cm the aortic root was remodelled (group III). Resuspension of the native aortic valve was undertaken in 11 patients with aortic root dilatation of > 5.0 cm (group IV). RESULTS: Operative intervention was electively performed in 72 patients, without any death. Of 29 patients operated as an emergency for acute type A dissection four died (14%). In 55 of the 58 patients with aortic regurgitation in proved possible to preserve native aortic valve (95%). In the early postoperative phase and after an average follow-up time of 11.8 months, transthoracic echocardiography demonstrated good aortic valve function, except in one patient each of groups III and IV who developed aortic regurgitation grades I or II. CONCLUSION: The described individualized approach makes it possible to preserve the native aortic valve in most patients with aortic regurgitation, at a low risk. Follow-up observations so far indicate good results of the reconstruction.     

The safety of dipyridamole-thallium imaging in patients with critical aortic valve stenosis and angina

BACKGROUND: Screening pretransplantation recipient sera for percent panel reactive antibodies (%PRA) by an anti-human globulin (AHG) assay may identify recipients who are at risk for graft rejection or development of posttransplantation coronary artery disease. However, the pretransplantation AHG-%PRA does not always correlate with the occurrence of graft rejection or coronary artery disease. METHODS: We compared the predictive capacity of the AHG-%PRA with that of an enzyme-linked immunoassay (EIA)-based PRA assay that identifies immunoglobulin G bound to soluble human leukocyte antigen (sHLA) class I molecules from pooled platelets of 240 random donors (sHLA-EIA), and that of an EIA-based assay that detects immunoglobulin G anti-HLA class I antibodies bound to sHLA derived from individual HLA-typed cell cultures (PRA-STAT). The pretransplantation sera from 130 cardiac allograft recipients were comparatively tested and results evaluated. RESULTS: Although AHG-%PRA- and sHLA-EIA-determined PRA results were comparable, neither assay discriminated potential recipients at risk for rejection or coronary artery disease. However, cardiac allograft recipients with pretransplantation PRA-STAT sera > 10% were at risk for (1) graft rejection (77% vs 56%, p < .05); (2) more rejections/recipient (1.9 vs 1.0, p < .02); (3) graft rejection within 30 days (92% vs 38%, p < .001); or (4) development of coronary artery disease (48% vs 23%, p < .05) than recipients with pretransplantation PRA-STAT sera < 10%. CONCLUSIONS: PRA-STAT analysis of pretransplantation sera from potential cardiac allograft recipients may be more clinically informative about HLA alloimmunity and a better predictor of adverse clinical events than either AHG-%PRA- or sHLA-EIA-determined PRA.     

Impact of size mismatch and left ventricular function on performance of the St. Jude disc valve after aortic valve replacement

BACKGROUND: The hemodynamic function of the St. Jude valve may change relative to changes in left ventricular function after aortic valve replacement for aortic stenosis. From theoretical reasons one may hypothesize that prosthetic valve hemodynamic function is related to left ventricular failure and mismatch between valve size and patient/ventricular chamber size. METHODS: Forty patients aged 24 to 82 years who survived aortic valve replacement for aortic stenosis with a standard St. Jude disc valve (mean size, 23.5 mm; range, 19 to 29 mm) were followed up prospectively with Doppler echocardiography and radionuclide left ventriculography preoperatively and 9 days, 3 months, and 18 months after the operation with assessment of intravascular hemolysis at 18 months. Follow-up to a maximum of 7.4 years (mean, 6.3 years) was 100% complete. RESULTS: Left ventricular muscle mass index decreased from 198 +/- 62 g.m-2 preoperatively to 153 +/- 53 g.m-2 at 18 months (p < 0.001), paralleled by a significant increase in left ventricular ejection fraction, peak ejection rate, and peak filling rate; only 18% of the patients had normal left ventricular muscle mass index and only 32% normal ventricular function (normal left ventricular ejection fraction, peak ejection rate, peak filling rate, early filling fraction, and late filling fraction during atrial contraction) at 18 months. Prosthetic valve peak Doppler gradient dropped from 20 +/- 6 mm Hg at 9 days to 17 +/- 5 mm Hg at 18 months (p < 0.05). Reduction of left ventricular muscle mass index was unrelated to peak gradient and size of the valve. Peak gradient at 18 months rose with valve orifice diameter of 17 mm or less (by 6 mm Hg), orifice diameter/body surface area of 9 mm.m-2 or less (by 5 mm Hg), left ventricular enddiastolic dimension (by 23 mm Hg per 10 mm increase), and impaired ventricular function (by 3 mm Hg). All but 2 patients (5%) had intravascular hemolysis; none had anemia. Two patients with moderate paravalvular leak had the highest serum lactic dehydrogenase levels; 4 patients with trivial leak had higher serum lactic dehydrogenase levels than those without leak. Serum lactic dehydrogenase levels rose with moderate paravalvular leak, impaired ventricular function, and valve orifice diameter. Six patients with trivial or moderate paravalvular leak had a cumulative 7-year freedom from bleeding and thromboembolism of 44% +/- 22% compared with 87% +/- 5% for those without leak (p < 0.05). CONCLUSIONS: The peak gradient of the St. Jude aortic valve dropped marginally over the first 18 postoperative months in association with incomplete left ventricular hypertrophy regression and marginal improvement of ventricular function. Mismatch between valve size and ventricular cavity size or patient size and impaired function of a dilated ventricle significantly compromised the performance of the St. Jude valve. Probably explained by platelet destruction or activation, paravalvular leak was related to bleeding and thromboembolic complications.     

Long-term results of fasting. Results from 132 consecutive patients after 1-6 1/2 years

132 consecutive patients were reexamined 1-6.5 years (m = 2.8) after total fasting in hospital. 37 patients had continued to lose weight, 20 patients had maintained their fasting result (+/-2 kg) and 7 patients had slightly regained (less than 1/3 of their weight loss during fast). These 3 groups, totalling 64 patients (48%), were considered successful. Their mean overweight was diminished from 57 to 29%, corresponding to a 60% reduction of mortality in certain age groups. On the other hand, 63 patients (48%) had regained more than 1/3 of their original weight loss. Five patients (4%) were lost to follow-up. Selection of patients and long-term follow-up appeared to have a decisive bearing on long-term results of fasting, whereas factors such as age, sex, degree of overweight, onset of overweight in childhood and sports were without significant effect. From the long-term results presented, it is concluded that under certain conditions fasting in hospital is warranted. Behaviour therapy is a possible alternative in the treatment of obesity.     

Dicrotic pulse observed in a patient with prolapse of the aortic valve without aortic regurgitation

We describe a case of dicrotic pulse in a patient who exhibited marked prolapsed aortic cusp without aortic regurgitation. Echo-Doppler in the abdominal aorta showed deep reversal flow confined to early diastole. We conclude that this prolapse was the cause of the steep dicrotic notch and the dicrotic pulse, because of the concomitance of non-leaking aortic valves.     

Tetanus in patients three years of age and up. A personal series of 230 consecutive patients

My experience with 230 patients with tetanus who were admitted to the intensive care unit of the H?pital Albert Schweitzer during a period of four years and four months is presented. We have observed a male predominance and the prognostic importance of age. The survival rate of over 84 per cent that we have achieved has resulted from the dedicated care of our nursing personnel and the collaboration of collegues of various specialties. Tetanus antitoxin, 10,000 units, is sufficient. Diazepam provides adequate relaxation and sedation. Gastrostomy and tracheostomy play a considerable role.