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C Schmidtke

Publications and source records attributed to C Schmidtke.

18 recordsLinked to original sources
PubMed2005

Echocardiographic and hemodynamic characteristics of reconstructed bicuspid aortic valves at rest and exercise.

Repair of diseased bicuspid aortic valves has gained increasing interest as an alternative to conventional valve replacement. Hemodynamic data at exercise have not been reported before. The aim of this study was to investigate the clinical and echocardiographic status of patients after bicuspid aortic valve repair at rest and exercise. Between 03/94 and 09/02 a reconstruction of an incompetent bicuspid aortic valve was performed in 25 patients (mean age 35+/-12.1 years, group A, mean insufficiency 2.8 preoperatively). Patients were investigated clinically and echocardiographically after 2.1+/-2.4 (0.1-8.9) years at rest and exercise and compared to 20 controls (group B). Clinical followup was complete. There were no deaths, reoperations, thromboembolic or bleeding complications. At last examination 21 patients were in NYHA class I, n=4 in NYHA class II and mean aortic valve insufficiency (AI) was 1.0 with one patient having an AI>II degrees. Maximum and mean pressure gradient (dPmax/mean) across the aortic valve at rest were 14+/-5.5/7+/-2.6 mmHg for patients of group A and 7+/-2.5/3.6+/-1.1 mmHg in group B. Mean AVA at rest was 2.6+/-0.8 (group A) vs 2.9+/-0.6 cm(2) (group B, p=0.025), valvular resistance 13.4+/-4.8 (group A) vs 13.6+/-2.9 dyn x s x cm(-5) (group B, p>0.05). All individuals were stressed up to 100 W (dPmax/mean 21+/-6.8/11+/-3.6, group A vs 11+/-2.9/6+/-1.3 mmHg, group B). 56% of group A and 85% of group B could be stressed up to 175 W with dPmax/mean 24.5+/-8.3/12+/-4.2 and 16+/-3.6/8+/-1.4 mmHg, respectively (p<0. 01). Heart rate and blood pressure behavior were comparable. Left ventricular mass regression (preoperatively 369.3+/-76.4 vs 277.3+/-80.7 g at last examination, p<0.01) was significant in group A but did not reach normal values (group B, 227.8+/-71.1; p<0.01). Bicuspid aortic valve reconstruction reduces left ventricular volume load significantly. Although residual mild subclinical obstruction and incompetence were observed, the behavior of hemodynamics at exercise was comparable to controls. The clinical relevance of these findings in long term follow-up has to be evaluated.

Adolescent↗
PubMed2003

[The Ross procedure (pulmonary autograft) as an alternative for aortic valve replacement].

BACKGROUND AND OBJECTIVE: The Ross procedure (pulmonary autograft) has since the 1980s attracted growing interest as an alternative to the widely practised insertion of a prosthetic aortic valve. The 12-year experience of a consecutive series from one centre are reported here. PATIENTS AND METHODS: Between February 1990 and January 2002 a Ross procedure, predominantly with the subcoronary technique, was performed in 244 consecutive patients with aortic valve disease (244 men, 54 women, mean age 46 +/- 13.5 years). Annual follow-up clinical examinations (mean postoperative period 32.9 +/- 29.5 months in 99 % of the cohort) were performed. RESULTS: Perioperative mortality was 0.8 % (n=2), and there were two late deaths unrelated to the aortic valve disease. Seven patients had to be re-operated for failure of the homograft (n=4) or autograft (n=4). According to clinical criteria, 99 % of the followed-up patients were in New York Heart Association (NYHA) functional class I or II, only two patients, with pulmonary comorbidity, were in class III. Echocardiography demonstrated autografts with nearly normal transvalvular gradient (mean maximal pressure gradient 6.5 +/- 3.3 mmHg), while nine patients had second-degree aortic regurgitation. The mean maximal gradient across the homograft valve in the pulmonary position was 12.0 +/- 6.9 mmHg, while ten patients had second-degree and one had third-degree pulmonary regurgitation. CONCLUSION: The technically demanding Ross procedure produced excellent clinical and hemodynamic mid-term results. It is thus an appealing alternative to the widely used replacement by a prosthetic valve. Definitive assessment awaits further long-term follow-up.

Adult↗
PubMed2003

Decellularized pulmonary homograft (SynerGraft) for reconstruction of the right ventricular outflow tract: first clinical experience.

INTRODUCTION: Cryopreserved homograft valve conduits have been used to reconstruct the right and left ventricular outflow tract. Long-term studies have shown homograft degeneration and calcification, and it has been postulated that immunological mediated phenomena in a manner similar to that seen in chronic rejection may contribute to the degeneration process. The development of a decellularized, non-glutaraldehyde-fixed valve conduit creates a non-immunogenic connective tissue matrix for autologous recellularization by host cells. The aim of the study was to characterize the clinical and hemodynamic pattern in human implants of the novel decellularized pulmonary homografts (SynerGraft). METHODS: Reconstruction of the right ventricular outflow tract was performed in 17 patients: 15 patients with aortic valve disease and the Ross procedure, and two patients with redo procedures following Fallot tetralogy and severe pulmonary regurgitation. Patients with the Ross procedure with standard cryopreserved homografts as neopulmonic conduits served as controls. Within the follow-up over six months morphological and hemodynamic parameters were characterized by echocardiography: maximal and mean pressure gradient across the right and left ventricular outflow tract, their effective orifice areas, determination of neopulmonic and neoaortic regurgitation. RESULTS: One patient died six weeks following surgical treatment due to non-valve related end-stage cardiopulmonary failure; all patients were free of valve-related complications during the follow-up period. The matched Ross patients showed a gradual but significant increase of both the maximal and mean pressure gradient across the right ventricular outflow tract (Delta P max 5.5+/-2.5 to 11.4+/-6.4 mmHg, p=0.002; Delta P mean 3.0+/-1.3 to 6.2+/-3.9 mmHg, p=0.003), whereas in the SynerGraft group increase of pressure gradients were measurable but did not reach statistical significance (Delta P max 7.1+/-3.7 to 10.1+/-3.9 mmHg, p=0.11; Delta P mean 3.6+/-1.6 to 5.5+/-2.3 mmHg, p=0.12). The pulmonary effective orifice areas decreased in the control group from 1.74+/-0.33 to 1.18+/-0.36 cm(2)/m(2) (p=0.001). Within the SynerGraft group time dependent reduction of the orifice area was significantly less (1.51+/-0.37 to 1.25+/-0.26 cm(2)/m(2); p=0.08). CONCLUSION: Up to six months after implantation reconstruction of the right ventricular outflow tract with decellularized homografts was safe, stable, and the morphological and hemodynamic features are promising.

Adult↗
PubMed2001

Time course of aortic valve function and root dimensions after subcoronary ross procedure for bicuspid versus tricuspid aortic valve disease.

BACKGROUND: The freestanding aortic root, which is the currently preferred operative technique for pulmonary autografts, is reported to dilate and potentially promote aortic insufficiency, which has led to a controversial debate on the appropriate surgical technique, especially for congenital bicuspid aortic valve disease. Desirable data on the time course of valve function and root dimensions for the alternative subcoronary technique comparing bicuspid and tricuspid aortic valve disease are scarce. METHODS AND RESULTS: Echocardiographic examinations of 31 patients with congenital bicuspid aortic valve disease (group A; age 50.5+/-11.0 years) and 51 patients with acquired tricuspid aortic valve disease (group B; age 48.1+/-15.7 years) who were operated on between June 1994 and August 1998 were performed twice postoperatively. At first and second follow-up, respectively, maximum (mean) pressure gradients were 6.0+/-2.0 (3.6+/-1.0) and 5.1+/-2.1 (2.9+/-1.1) mm Hg in group A and 6.5+/-3.5 (3.9+/-1.9) and 5.0+/-1.7 (2.9+/-1.0) mm Hg in group B (P>0.05 between groups). In group A, grade 0 aortic insufficiency at first and second follow-up occurred in 8 and 7 patients, respectively, grade 0-I in 12 and 9 patients, grade I in 9 and 11 patients, grade I-II in 1 and 0 patients, and grade II in 1 and 4 patients; in group B, grade 0 aortic insufficiency occurred in 16 and 18 patients, grade 0-I in 16 and 8 patients, grade I in 17 and 21 patients, grade I-II in 0 and 1 patient, and grade II in 0 and 1 patient (P>0.05). Aortic insufficiency decreased in 10 patients (17%). However, there was an overall tendency for aortic insufficiency to increase over time (n=23, 38%), although it remained subclinical. Aortic root dimensions did not differ between groups and were constant during follow-up. CONCLUSIONS: This study provides some evidence that the function of the subcoronary pulmonary autograft in bicuspid aortic valve disease is excellent, with stable root dimensions, and is not different from that of tricuspid aortic valves at least up to 5.5 years postoperatively, which suggests the subcoronary technique should be reconsidered.

Adult↗
PubMed2001

Does histocompatibility affect homograft valve function after the Ross procedure?

BACKGROUND: Homograft valves have been shown to be immunogenic, but it is unknown whether this affects valve function. Therefore, we prospectively studied the degree of histoincompatibility (defined as the number of human leukocyte antigen [HLA] mismatches between valve donor and recipient) and the response of the recipient (measured by antibodies against HLA) in relation to echocardiographic parameters of homograft valve function after the Ross procedure. METHODS AND RESULTS: Twenty-six patients (mean age 41+/-14 years; 20 males, 6 females) and the cryopreserved pulmonary homograft valves that were implanted during a Ross procedure were typed for HLA-A, HLA-B, and HLA-DR. After a mean follow-up of 15+/-6 months, 14 (54%) of the patients were anti-HLA class I antibody positive. In all but 1 patient, these antibodies were shown to be donor specific. During follow-up, there was a significant increase of the maximal (+6.2+/-7.1 mm Hg) and mean (+3.2+/-4.3 mm Hg) transhomograft pressure gradients but not of homograft regurgitation. Neither the number of HLA mismatches nor antibody status was found to have significant impact on homograft valve function. In a multivariate analysis, smaller homograft size (P=0.001) and younger recipient age (P=0.044) were shown to be significantly associated with increased transhomograft pressure gradients. CONCLUSIONS: Implantation of a cryopreserved pulmonary homograft during the Ross procedure can induce a specific humoral response. We observed a significant increase of the transhomograft pressure gradients within 15+/-6 months after surgery. For this period, we were unable to demonstrate a relationship between this increase and the degree of histoincompatibility.

Adult↗
PubMed2001

Quality of life in aortic valve replacement: pulmonary autografts versus mechanical prostheses.

OBJECTIVES: We sought to determine whether the quality of life (QoL) is different in patients after aortic valve replacement with mechanical prostheses or pulmonary autografts. BACKGROUND: Quality of life after mechanical valve replacement may be affected by the risk of thromboembolism and anticoagulation, and after autograft implantation, by the risk of degeneration and re-operation especially of the homograft. METHODS: Two groups of 40 patients each--one after the autograft procedure (group I) and one after mechanical valve implantation (group II)--were matched for age, gender and length of follow-up. At latest follow-up, all patients underwent routine echocardiography, the short-form health survey (SF-36) QoL survey and an extensive psychological investigation. RESULTS: Patients with an autograft showed better QoL scales, as compared with mechanical valve recipients. The difference was significant for both the physical (72.72+/-20.00 vs. 60.27+/-26.07, p = 0.021) and psychological health sum scores (74.71+/-21.03 vs. 64.71+/-23.49, p = 0.046) and for the subtests of physical functioning (73.72+/-22.44 vs. 62.77+/-25.42, p = 0.049), physical pain (88.39+/-19.13 vs. 73.36+/-27.08, p < or = 0.006), general health perception (64.37+/-17.88 vs. 51.86+/-22.86, p < or = 0.008) and health change (61.89+/-18.94 vs. 50.11+/-24.37, p = 0.02). The QoL variables did not correlate to pressure gradients, ejection fraction and New York Heart Association functional class. Psychometric tests revealed no meaningful differences between the groups. CONCLUSIONS: This study provides some evidence that patients with pulmonary autografts have greater benefit in terms of QoL, as compared with recipients of mechanical valve substitutes.

Aortic Valve↗
PubMed2001

[Quality of life after aortic valve replacement. Self-management or conventional anticoagulation therapy after mechanical valve replacement plus pulmonary autograft].

BACKGROUND: The improvement of quality of life gains increasing importance for the judgement of operative techniques. Besides the commonly used mechanical substitutes or bioprostheses for aortic valve replacement, the interest in the Ross procedure is growing. The aim of the study was to compare the quality of life after the Ross procedure with that after mechanical aortic valve replacement with two different anticoagulation regimes (self-management or conventional therapy). METHODS AND RESULTS: Clinical, echocardiographic and quality of life investigations (SF-36) were performed in patients with mechanical aortic valve replacement and self-management of anticoagulation (group A, n = 20) or conventional anticoagulation therapy (group B, n = 20) and in patients after the Ross procedure (group C, n = 20). The mean ages were 59.5 +/- 9.2 (group A), 61.2 +/- 8.1 (group B) and 59.3 +/- 9 years (group C). Significantly lower values of quality of life (SF-36) were observed in group B compared with group A (5 of 9 subtests) and with group C (6 of 9 subtests) and also in the physical and mental health sum scales. CONCLUSION: In this study the quality of life in patients after the Ross procedure and similarly after mechanical valve replacement and self-management of anticoagulation is superior to the quality of life after mechanical valve replacement and conventional anticoagulation.

Adult↗
PubMed2001

Anti-HLA class I antibodies and pulmonary homograft function after the Ross procedure.

BACKGROUND: The Ross procedure provides excellent long-term results in the majority of patients. However, degeneration of the pulmonary homograft in some patients remains an unresolved problem that may be related to immunologic factors. Therefore, we studied the prevalence of antihuman leukocyte antigen (HLA) class I antibodies and echocardiographic results of homograft function at rest. METHODS: Forty-seven patients (37 men, 10 women; 47 +/- 15 years) were seen for echocardiography 1.1 to 63.9 months (median, 27 months) postoperatively. The presence of anti-HLA antibodies was tested against a panel of lymphocytes of 50 donors. RESULTS: Twenty-seven (57%) of the patients produced anti-HLA class I antibodies. No difference in the maximal or mean transhomograft pressure gradient, or in the frequency of homograft regurgitation according to the presence or absence of anti-HLA antibodies was found. However, the right ventricle was slightly but significantly larger in antibody-positive patients (26.3 +/- 4.2 versus 30.7 +/- 3.5 mm; p = 0.001). CONCLUSIONS: In the first years after the Ross procedure, we could not detect significant evidence of an association between anti-HLA class I antibodies and echocardiographic results of homograft function at rest in adults.

Adult↗
PubMed2001

Hemodynamics of semilunar valves at rest and exercise at an average of more than two years after the Ross procedure.

BACKGROUND AND AIM OF THE STUDY: Rest, and especially exercise, hemodynamics are valuable determinants to assess outcome of the Ross procedure. In this study, the degree of insufficiency and pressure gradients at rest across the autograft and homograft, as well as the pressure gradients at exercise, were measured. METHODS: Among 115 patients operated on between February 1990 and February 1999, 67 were evaluated echocardiographically at rest and moderate exercise. The mean patient age at subcoronary implantation was 52 +/- 13 years. The mean interval between surgery and investigation was 27.3 +/- 17.4 months. The exercise level was 100 W (n = 47), 75 W (n = 14) or 50 W (n = 6). RESULTS: Fifty-two patients had no or trace aortic insufficiency, 23 were grade I/IV, and two were grade II/IV. Pulmonary insufficiency was graded as none (n = 45), mild (n = 21), and moderate (n = 1). Heart rate increased from 70 +/- 12 beats/min at rest to 108 +/- 19 beats/min at exercise. The maximal pressure gradient across the autograft increased from 6.1 +/- 2.3 mmHg at rest to 8.7 +/- 4.1 mmHg at exercise. The maximal pressure gradient across the homograft increased from 11.8 +/- 5.3 mmHg at rest to 17.7 +/- 8.2 mmHg at exercise. A pressure gradient across the homograft >25 mmHg was measured in 13 patients. CONCLUSION: In most patients, hemodynamics at rest and moderate exercise at an average of more than two years after the Ross procedure were excellent. Some homografts developed pressure gradients at exercise; this finding will form the target of future surgical and scientific investigations.

Adult↗
PubMed2000

Valve-sparing aortic root replacement (remodeling/reimplantation) in acute type A dissection.

BACKGROUND: High reoperation rates after supracommissural tube graft replacement for acute type A dissection due to sinus of Valsalva dilation have been reported. Valve-sparing operations focusing on the replacement of the sinus of Valsalva are an appealing alternative. The applicability of these techniques in acute type A dissection remains debatable and results are limited. METHODS: From 1992 to 1998, 20 patients with acute type A dissection received a valve-sparing aortic root replacement. Two different types of aortic valve-sparing operations were performed: the remodeling technique in 11 patients and the reimplantation technique in 9 patients. Patients were followed for 26 +/- 18 months. Echocardiographic studies were performed every 6 months. RESULTS: There were 2 early postoperative deaths and no late death, no reoperation, and no thromboembolic events. The latest echocardiographic studies of the 18 survivors showed a competent valve in 12 and a trivial aortic valve insufficiency in 6 patients. The mean aortic valve pressure gradient was 4.3 +/- 1.3 mm Hg. CONCLUSIONS: These midterm results support the surgical strategy of valve-sparing aortic root replacement in patients with acute type A dissection.

Aortic Dissection↗
PubMed2000

Size and distensibility of the aortic root and aortic valve function after different techniques of the ross procedure.

OBJECTIVES: In the Ross procedure, 3 different techniques are used for aortic valve replacement with the pulmonary autograft: freestanding root, inclusion, and subcoronary implantation. The objective of this study was to evaluate echocardiographically the influence of the particular operative technique on dimension, distensibility, and valve function. METHODS: Between February 1990 and August 1998, the Ross procedure was performed in 111 patients (mean age, 48.6 +/- 14.1 years; range, 15.2-70.6 years), with 1 early and 1 late death, 1 autograft replacement, and 1 patient lost to follow-up. The remaining patients underwent the freestanding root (n = 9 patients), inclusion (n = 14 patients), and subcoronary techniques (n = 84 patients). Echocardiography was performed at a mean follow-up of 26 +/- 21.3 months after operation and was compared with the echocardiographic findings of the control subjects (n = 10 subjects). Root sizes were measured at the level of the anulus, sinus, and supra-aortic ridge; the distensibility was calculated as pressure strain elastic modulus and percent change of radius. RESULTS: Size and distensibility of the aortic root were normal, except for a larger diameter at the sinus level in the root technique in comparison to the subcoronary technique (P <.05; maximum diameter, 41.3 +/- 8.6 mm vs 32.6 +/- 4.0 mm). Aortic valve function was comparable among groups with low pressure gradients and most patients with no or trace aortic insufficiency. CONCLUSIONS: The freestanding root, inclusion, and subcoronary techniques in the Ross procedure provide comparable excellent hemodynamics, normal root size, and distensibility, except for the enlarged sinus diameter in the freestanding root. These results may have some impact on the operative procedure and follow-up investigations.

Adult↗
PubMed2000

Up to seven years of experience with the Ross procedure in patients >60 years of age.

OBJECTIVES: The objective of this study was to compare the outcome of patients >60 years of age with younger patients after the Ross procedure. BACKGROUND: Currently, the Ross procedure is performed predominantly in young patients. Main arguments against the Ross procedure in the elderly are the complexity of the operation and related risks. Experience with the Ross procedure in patients >60 years of age is scarce. METHODS: Between February 1990 and August 1998, the Ross procedure was performed in 27 patients (15 men and 12 women) >60 years of age (mean 64.2 +/- 3.1 years, range 60.5 to 70.6; group A) and in 84 patients (68 men, 12 women) <60 years of age (mean 43.8 +/- 12.4 years, range 15.2 to 59.4; group B). Echocardiography was applied at a mean follow-up of 28.4 +/- 21.0 and 25.2 +/- 21.4 months, respectively, to determine hemodynamic variables (ejection fraction, fractional shortening, stroke volume, cardiac output), cardiac dimensions and autograft and homograft valve function. RESULTS: There was one early and one late (esophageal bleeding) death in group B; the mortality rate was 0% in group A. One autograft was replaced because of a subvalvular aneurysm, and one patient was lost to follow-up (group B). There were no significant differences in cardiac dimensions, grade of insufficiencies across homografts and autografts and hemodynamic variables, except for a higher pressure gradient across the homograft in group B (maximal pressure gradient 11.3 +/- 5.6 vs. 7.7 +/- 4.6 mm Hg in group A). The median New York Heart Association functional class was I in both groups. CONCLUSIONS: Our seven years of experiences (mean follow-up 28 months) indicate that the Ross procedure may be performed in selected patients >60 years of age without increased risk for mortality or complications in experienced centers.

Adolescent↗
PubMed1999

Opening and closing characteristics of the aortic valve after different types of valve-preserving surgery.

BACKGROUND: The surgical approach to aortic root aneurysm and/or dissection remains controversial. The use of valve-sparing operations, which are thought to have many advantages, is increasing. We hypothesized that the particular technique and type of surgery could influence valve motion characteristics and function. Therefore, we studied the instantaneous opening and closing characteristics of the aortic valve after the main 2 types of valve-sparing surgery. METHODS AND RESULTS: In 20 patients (10 with tube replacement of the aortic root, group A; and 10 with separate replacement of the sinuses of Valsalva, group B) and 10 controls (group C), transthoracic and transesophageal studies on aortic valve dynamics were performed. Three distinct phases of aortic valve motion were identified. They were as follows: (1) a rapid opening, with a velocity of 20.9+/-4.2 cm/s in group C, 27.1+/-10.9 cm/s in group B (P=NS), and 58.3+/-18.4 cm/s in group A (group A versus group C, P<0. 001; group A versus group B, P=0.001); (2) a slow systolic closure, with 12.5+/-6.6% and 10.8+/-2.2% of maximal opening in groups C and B, respectively (P=NS), and 3.8+/-1.6% in group A (group A versus group C, P=0.001; group A versus group B, P<0.001); and (3) a rapid closing movement, with a velocity of 26.3+/-5.6 cm/s in group C, 32. 4+/-11.4 cm/s in group B (P=NS), and 21.8+/-3.5 cm/s in group A (group A versus group C, P=NS; group A versus group B, P=0.008). The pressure strain of the elastic modulus was different in groups C and B only at the commissures (682+/-145 g/cm(2) versus 1896+/-726 g/cm(2), respectively; P<0.001). At all root levels, the distensibility was reduced in group A (P<0.001). Systolic contact of aortic cusps and wall occurred only in group A. CONCLUSIONS: Near-normal opening and closing characteristics can be achieved by a technique that preserves the shape and independent mobility of the sinuses of Valsalva.

Adult↗
PubMed1999

Effects of intensified antihypertensive treatment in diabetic nephropathy: mortality and morbidity results of a prospective controlled 10-year study.

OBJECTIVE: The aim of this study was to describe the effect of intensified antihypertensive therapy based on a structured teaching and treatment programme on the prognosis of hypertensive type 1 (insulin-dependent) diabetic patients with kidney disease. DESIGN: The study was a controlled, prospective, parallel, 10-year follow-up trial. PATIENTS AND INTERVENTIONS: A sequential sample of 91 hypertensive type 1 diabetic patients with overt diabetic nephropathy was prospectively followed for 10 years. Forty-five patients (intensified antihypertensive therapy; IT group) participated in an intensified antihypertensive therapy programme and 46 patients received routine antihypertensive treatment as provided by family physicians, consultants and local hospitals (routine antihypertensive therapy; RT group). OUTCOME MEASURES: The main endpoint was death; secondary endpoints were renal replacement therapy, blindness and amputation. RESULTS: Blood pressure was reduced in the IT group and increased in the RT group. During the follow-up period, 29 patients died, seven in the IT group and 22 in the RT group. The survival curves were significantly different (P = 0.0008). The main causes of death were cardiac. In a multiple Cox proportional hazards model, allocation to the IT group reduced the mortality risk [relative risk (RR) = 0.213; 95% confidence interval 0.089-0.509, P = 0.00051, while age (P = 0.0039) and mean blood pressure (P= 0.0113) increased this risk. In multiple Cox or multiple logistic regression models, the risks of dialysis (RR = 0.269, 95% confidence interval 0.110-0.656, P = 0.0039), blindness (odds ratio = 0.158, 95% confidence interval 0.037-0.684, P= 0.0136), and amputation (RR = 0.181, 95% confidence interval 0.047-0.703, P= 0.0135) were significantly lower in the IT group compared with the RT group (log rank P = 0.0008). CONCLUSION: We conclude that intensified antihypertensive treatment, based on a hypertension teaching and treatment programme, reduces long-term morbidity and mortality in patients with diabetic nephropathy.

Adult↗
PubMed1998

Electron-microscopic findings after transmyocardial laser revascularization in an acute ischemic pig model.

OBJECTIVE: The clinical benefit in terms of angina reduction after transmyocardial laser revascularization (TMLR) in patients with diffuse coronary artery disease who are not candidates for conventional procedures has been proved. The exact mechanisms of TMLR however, are still unknown. The aim of this study was to investigate the cellular changes in relation to intramyocardial partial oxygen pressure (ptiO2) after TMLR in a model of acute ischemia in pigs by electron microscopical methods (TEM). METHODS: Seven pigs were included in this study (five animals with acute myocardial ischemia and additional TMLR and two animals with acute myocardial ischemia and without TMLR for control). Acute ischemia was induced by ligation of diagonal branches of the left anterior descending artery (LAD). Intramyocardial partial oxygen pressure was measured before induction of ischemia and thereafter continuously for up to 6 h in all animals. Biopsies of all animals were taken before induction of ischemia and thereafter at 30 min, 3 and 6 h. Analysis of the myocardial ultrastructure was focused on mitochondria, cell nucleus, T-tubules and myofibrils. RESULTS: Ultrastructural changes were seen in all animals. At 6 h after induction of ischemia, mitochondria showed a destruction of the internal as well as the external membrane and of the cristae. The nuclei showed margination of the chromatin. Myofibrils were characterized by ruptures in the Z-stripes. Lipid droplets as an indicator of ischemia could be identified. PtiO2 between 40 and 80 mmHg before intervention decreased down to 0-2 mmHg within the first 9 min after diagonal branch ligation and did not increase even after TMLR. CONCLUSIONS: In this acute ischemic model using pigs, TEM evaluation following TMLR proves irreversible changes of the myocardial ultrastructure. Furthermore, TMLR was not able to increase ischemically induced decrease of ptiO2. These data provide some evidence that TMLR thus, may not be able to ameliorate acute ischemia at least in the pig model. Further investigations are needed to investigate the effect of TMLR in chronic myocardial ischemia.

Animals↗
PubMed1998

Long-term follow-up after resectional surgery in patients with Crohn's disease involving the colon.

BACKGROUND: The majority of patients with Crohn's disease will eventually have colonic involvement, and more than 50% of these patients undergo resectional colonic surgery. The extent of colonic resection is discussed controversially. AIMS: We evaluated prognostic factors influencing the long-term outcome after resectional surgery including the colon. METHODS: We analyzed the postoperative course in 170 patients (mean follow-up 7.4 years) after first colonic surgery. Lifetable and multivariate factor analysis were performed to assess the influence of various factors on the postoperative long-term outcome. 85% of the patients had concomitant ileal disease, 40% had rectal disease, 48% percent of the patients had extensive colonic disease at the time of primary surgery. RESULTS: In 17% of the initial operations a colectomy was performed, the remaining 83% operations consisted in segmental colonic resections. The cumulative risks of clinical recurrence/reoperation were 63%/33% after ten years and increased by the presence of anal fistulas (relative risk 1.7/3.0) and after colocolonic type of anastomosis (relative risk 1.9/2.8). Ileal disease, rectal disease, extent of resection and pattern of colitis did not influence the recurrence rates. The risk to undergo completion colectomy was 11% ten years after segmental resection and not higher in the presence of extensive colonic disease. The risk of a definitive stoma was 11% after ten years and higher after ileorectal anastomosis (25% versus 8% after segmental resection: p < 0.003). CONCLUSION: Colocolonic type of anastomosis and the presence of anal fistulas are risk factors for recurrence after initial colonic resection. Segmental resections were not followed by increased recurrence rates or a higher stoma rate. To maintain colonic length and intestinal continuity segmental colonic resection is the treatment of choice in patients undergoing surgery for local complications, even in the presence of extensive colonic disease.

Adult↗
PubMed1997

Progression and prognosis of Crohn's colitis.

BACKGROUND: Inflammation refractory to medical treatment frequently characterizes the course of Crohn's colitis, often leading to colectomy and need for a stoma. The influence of disease extent within the colon on prognosis and disease progress over time has not been studied so far. AIMS: We evaluated the disease progress and the long-term outcome in 323 patients with Crohn's colitis followed-up for a mean of 9.8 years. METHODS: The charts were analyzed retrospectively, the mean number of documented examinations was 18.5 per patient. The influence of disease pattern, rectal disease and perianal fistulas on the long-term outcome was evaluated using actuarial methods and independent factor analysis. RESULTS: The probabilities of having pancolitis or rectal disease were 77.1% and 78.8% after 15 years, respectively, and higher in patients with initially left-sided or segmental colitis compared with right-sided colitis. The chance of having perianal fistulas was 43.3% after 15 years. The risk of undergoing resectional colonic surgery was 62.2% after 15 years and higher in the presence of right-sided colitis. The cumulative risk of colectomy was 18.2% after 15 years and higher in patients with pancolitis, left-sided colitis or in the presence of perianal fistulas. The 15-year probabilities of proctectomy (12%) and of having a temporary stoma (21%) were only influenced by the presence of perianal fistulas but not by rectal disease or pattern of colitis. CONCLUSIONS: Most patients with colonic Crohn's disease will eventually have pancolitis but only 20% of them will loose the colon. The proctectomy rate is low despite a high frequency of rectal disease. Perianal fistulas and the presence of total or left-sided colonic involvement are adverse risk factors with regard to preservation of colonic length.

Adult↗