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Biomedical subjects

P Brücke

Publications and source records attributed to P Brücke.

At least 19 recordsLinked to original sources
PubMed2000

Comparison of progression of macrovascular diseases after kidney or pancreas and kidney transplantation in diabetic patients with end-stage renal disease.

AIMS/HYPOTHESIS: The aim of the study was to examine the effect of pancreas-kidney transplantation on the progression of macrovascular diseases in Type I diabetic patients with end-stage renal disease. METHODS: The progression of cerebrovascular disease, coronary heart disease and peripheral vascular disease in uraemic patients with Type I (insulin-dependent) diabetes mellitus and who had had simultaneous pancreas-kidney transplantation was compared with that of recipients of a kidney transplant alone. Between 1986 and 1998 a total of 11 uraemic diabetic patients received a simultaneous pancreas-kidney transplantation and 10 diabetic patients a kidney transplant alone. All transplants functioned for at least 24 months, the mean observation period was 69 +/- 37 compared with 70 +/- 33 months in both patient groups. Macroangiopathic diseases were classified in four stages as described earlier. RESULTS: In the group with simultaneous pancreas-kidney transplantation progression of cerebrovascular and coronary heart disease was observed in four patients (36%) and progression of peripheral vascular disease in five subjects (45%). In the cohort with kidney transplant alone four patients (40%) showed progression of cerebrovascular and coronary heart disease and five progression of peripheral vascular disease (50%); the difference is not significant. Mean values of HbA1c (5.8 +/- 0.2 vs 7.5 +/- 0.6%, p < 0.001) and serum triglycerides (1.2 +/- 0.4 vs 2.0 +/- 1.0 mmol/l, p < 0.05) were significantly lower in the patients with pancreas-kidney transplantation than in the patient group with kidney transplant alone. Serum cholesterol concentrations and blood pressures were similar in both cohorts. CONCLUSION/INTERPRETATION: From our results we concluded that pancreas-kidney transplantation reduces risk factors for the development of macroangiopathy but fails to halt progression of macrovascular diseases similar to Type I diabetic patients with kidney transplant alone.

Adult↗
PubMed2000

The incidence of thrombovenous and thromboembolic complications in kidney transplant patients with recurrent glomerulonephritis is dependent on the occurrence of severe proteinuria.

BACKGROUND: Patients with recurrent glomerulonephritis (RG) after kidney transplantation are at high risk for thromboembolic events but it is unclear when the risk begins to increase. PATIENTS AND METHODS: We evaluated the risk for thrombovenous and thromboembolic complications in relation to the occurrence of severe proteinuria (> or = 2 g protein in 24-hour urine) in 15 renal allograft recipients with biopsy-proven RG, who had received 20 allografts RG. The total period of observation was 53 (10-91) months. The post-transplant period before the occurrence of severe proteinuria lasted 18 (1-34) months and the subsequent proteinuric period until the end of the study, 35 (9-85) months. RESULTS: The monthly incidence of thrombovenous and thromboembolic complications was only 1/18 in the first period before and in contrast, 11/35 in the subsequent period after the occurrence of severe proteinuria. The mean urinary protein excretion increased from 0.4 +/- 0.1 g/day immediately after transplantation to 6.1 +/- 4.8 g/day at the end of the study (p < 0.001). During the same period there was a 1.2-fold increase of fibrinogen (from 366 +/- 88 to 442 +/- 120 mg/dl, p < 0.025) and a 1.2-fold decrease of antithrombin III (from 110 +/- 12 to 92 +/- 12%, p < 0.001). All thrombotic complications occurred in 6 patients with 9 grafts; at the end of the study this group showed higher fibrinogen concentrations (454 +/- 155 versus 433 +/- 89 mg/dl, NS) m and lower antithrombin III levels (88 +/- 11 versus 97 +/- 11%, p < 0.05) than the group without thrombotic complications. CONCLUSION: In kidney transplant patients with RG a high risk for thrombovenous and thromboembolic complications can be obs- served after the occurrence of severe proteinuria; this can mainly be explained by high fibrinogen and low antithrombin III levels. Anticoagulation therapy should be started in patients with RG immediately after the occurrence of severe proteinuria.

Adult↗
PubMed1999

Aortic valve replacement: is the stentless xenograft an alternative to the homograft? Midterm results.

BACKGROUND: This study was performed to assess the midterm clinical results after aortic valve replacement (AVR) with stentless xenograft (SX) compared with cryopreserved aortic or pulmonary homografts (HX). METHODS: In 139 patients (<60 years) undergoing elective AVR, 59 HX and 80 SX were inserted. All patients were followed clinically and by color flow Doppler echocardiography for 45+/-12 months (range 31-58 months). RESULTS: There were 5 in-hospital deaths (3.5%): 4 HX and 1 SX (p = NS). The mean gradient was 6+/-2 mm Hg in HX versus 13+/-6 mm Hg in SX (p<0.001) and remained unchanged during follow-up. Actuarial survival (HX 77%, SX 80%), freedom from endocarditis (HX 91%, SX 99%), freedom from thromboembolic events (HX 98%, SX 90%), and freedom from reoperation (HX 98%, SX 100%) were comparable between groups after 58 months. CONCLUSIONS: Despite slightly higher transvalvular gradients, the stentless aortic valve achieved excellent midterm results, when compared with homografts.

Actuarial Analysis↗
PubMed1999

Midterm results after aortic valve replacement with the autologous tissue cardiac valve.

OBJECTIVE: To assess midterm results after aortic valve replacement (AVR) with an autologous tissue cardiac valve (ATCV). This new technique was developed to construct a tissue prosthesis for AVR using the patients pericardium, harvested at the time of operation with negligible effect on operating time. METHODS: Briefly, glutaraldehyde tanned pericardium is mounted on a stent requiring no suturing. Between March 1994 and December 1996, 87 patients, 44/43 M/F and aged 70 +/- 6 years had AVR for aortic stenosis (80%), aortic insufficiency (6%) and combined lesions (14%), one patient suffered from endocarditis. Additional coronary artery bypass was done in 25%, aortic root enlargement in 7%. Aortic cross clamp and cardiopulmonary bypass times were 69 +/- 21 and 93 +/- 29 min. All patients were followed by clinical examination and color flow Doppler echocardiography in 3-12 months interval. Follow up was 99% complete. RESULTS: There were five perioperative deaths (6%), none of them valve related. Eighty-one patients were followed up to a period of 52 months (mean interval 37.5 +/- 1.3 months), one patient was lost for follow up. Overall survival was 86, 81, 79 and 71% at 12, 24, 36 and 48 months, respectively. There were 14 late deaths with eight (10%) valve related (four cerebral deaths, four sudden deaths). Sixteen patients (20%) had to be re-operated due to severe valve incompetence. Freedom from reoperation was 98, 97, 90 and 63% at 12, 24, 36, and 48 months, respectively. Valve incompetence occurred suddenly, without previous signs in the follow-up examinations. Selection and preparation of the pericardium, the way of fixation of the tissue--brief immersion in glutaraldehyde--and engineering problems might be responsible for this disastrous outcome. CONCLUSION: Due to these results we must state, that the ATCV did not fulfill our expectations and presently we can not recommend it as an aortic valve substitute.

Aged↗
PubMed1998

Aortic homografts versus mechanical valves in aortic valve replacement in young patients: a retrospective study.

BACKGROUND: Whether aortic homografts (AH) or mechanical devices (MD) are the valves of choice for aortic valve replacement in young patients (age 20 to 50 years) is unclear. Hence, we examined all aortic valve replacements performed with AH and MD in a retrospective study. METHODS: Between 1988 and 1995, 45 patients (mean age, 38.6+/-8.5 years) underwent aortic valve replacement with an AH and 40 patients (mean age, 42.0+/-7.2 years) with an MD. Patients' demographic data were comparable in all respects, except acute endocarditis, which was an absolute indication for the use of an AH. RESULTS: The mean follow-up time was 51.7+/-22.6 months for AH versus 44.6+/-26.9 months for MD (not significant). There were significant differences in postoperative outcome among the two groups (p < or = 0.05): perioperative death (4 versus 0 for AH and MD, respectively); reoperation (8 for AH versus 0 for MD); and endocarditis (5 versus 0 for AH and MD). There were higher incidences of embolism (2 versus 0) and hemorrhage (2 versus 0) in MD compared with AH. Only late death was comparable among the two groups with 5 patients in each group. CONCLUSIONS: The mechanical valves in our midterm follow-up are superior to homografts. However, embolic and hemorrhagic complications in MD are continuously impending and cumulative during a long-term follow-up. The surprisingly high rate of endocarditis in the AH group is only partly caused by the indication: 2 cases were recurrent, but there were also 2 new onsets of endocarditis. In 4 cases structural deterioration was responsible for reoperation. Aortic valve replacement with aortic homografts showed a rather unfavorable midterm outcome in this selected group of young patients. A surprisingly high rate of graft endocarditis and structural deterioration led to subsequent reoperations. Although our results with mechanical valves are satisfying, embolism and hemorrhage are impending risk factors for many years to come in these young patients.

Adult↗
PubMed1998

Cardiac valve endothelial cells: relevance in the long-term function of biologic valve prostheses.

OBJECTIVE: For reasons that are still unclear, biologic heart valve prostheses undergo degeneration after implantation. We studied the possible role of the immune system in this process. METHODS: We examined the expression of immunologically relevant molecules by human cardiac valve endothelium in situ and in vitro and studied re-endothelialization of implanted allogeneic and xenogeneic valvular surfaces using explanted bioprostheses and valves obtained from donor hearts at cardiac retransplantation. RESULTS: We demonstrate that human cardiac valve endothelial cells express molecules capable of initiating immune responses and might therefore play a role in the degeneration of viable cardiac valve prostheses. Also, we show evidence of re-endothelialization on the surfaces of xenografts and allografts but not on valves obtained from previously transplanted hearts. CONCLUSION: Inasmuch as valves from previously transplanted hearts seem to be free from degeneration, we conclude that reduction of the immunogenicity of allograft valve prostheses by HLA matching or immunosuppressive treatment might further improve long-term results after allograft valve replacement.

Antigens, CD↗
PubMed1998

Bilateral nephrectomy: the best, but often overlooked, treatment for refractory hypertension in hemodialysis patients.

Bilateral nephrectomy for treatment of refractory hypertension in chronic hemodialyzed patients has been infrequently carried out. We analyzed the benefits of this operation on blood pressure, clinical state, drug treatment, and quality of life. In 10 hemodialyzed patients with refractory hypertension, systolic (SBP) and diastolic (DBP) blood pressure were measured 1 month before nephrectomy bilateral and 3, 6, 9, and 12 months after. In addition, the use of antihypertensive drugs before and after surgery was evaluated. Four patients had SBP and DBP values characteristic of malignant hypertension. In all 10 patients hypertension responded neither to reduction of plasma volume by ultrafiltration nor to multiple antihypertensive drug therapy. Hypertensive crises were associated with cerebral hemorrhage in two patients, severe encephalopathy with persistent neural dysfunction in one patient, and encephalopathy and diplopia in another. Three months after bilateral nephrectomy blood pressure decreased significantly (P < .005) and was normal in nine patients. In one noncompliant patient with intradialytic body weight increases of nearly 10%, blood pressure was still elevated. Malignant or drug-resistant hypertension with hypertensive crises is an indication for bilateral nephrectomy. The clinical state and quality of life improved in all patients in the present study and antihypertensive treatment is no longer necessary.

Adult↗
PubMed1997

Efficacy and safety of a low-molecular-weight heparin and standard unfractionated heparin for prophylaxis of postoperative venous thromboembolism: European multicenter trial.

A randomized, double-blind multicenter trial was performed to compare the safety and efficacy of a new low-molecular-weight heparin (LMWH) (LU 47311, Clivarine) and standard unfractionated heparin for the prophylaxis of postoperative venous thromboembolism. Altogether 1351 patients scheduled to undergo abdominal surgery were included. Main outcome measures included the incidence of thromboembolic events (deep vein thrombosis, pulmonary embolism, or both) and bleeding complications, including wound hematoma. A total of 655 patients received 1750 anti-Xa IU of LMWH plus a placebo injection daily; 677 patients received 5000 IU of unfractionated heparin (UFH) twice a day. Both drugs were found to be equally effective, as 4.7% of patients in the LMWH group and 4.3% in the UFH group developed postoperative thromboembolic complications. However, the incidence of bleeding complications was significantly reduced in the LMWH group: 55 (8.3%) patients in the LMWH group and 80 (11.8%) in the UFH group developed bleeding complications, a relative risk (RR) of 0.70 (95% CI 0.51-0.97;p = 0.03); wound hematoma occurred in 29 (4.4%) of the LMWH group compared with 55 (7.7%) in those in the UFH group for an RR of 0.57 (95% CI 0.37-0.88;p = 0.01). This study confirmed that a very low dose of 1750 anti-Xa IU daily of this new LMWH is as effective as 10,000 IU of UFH for preventing postoperative deep vein thrombosis. At this dose its administration is associated with a significant reduction in the risk of bleeding including wound hematoma.

Adult↗
PubMed1997

Influence of case scheduling on outcome in cardiac surgery.

OBJECTIVE: Whether scheduling of patients for cardiac surgery as dictated by the availability of cardiopulmonary machines (CPBM) may influence postsurgical outcome, thought not to be an issue in the past, is unknown. EXPERIMENTAL DESIGN AND SETTING: Cardiac surgical outcomes were compared between two consecutive 12 months intervals surrounding the acquisition of a second CPBM by our department in a general hospital. PATIENTS: Patients in Group A (n=416) underwent surgery when only 1 CPBM was available (February 1990-January 1991) and in Group B (n=603) when 2 CPBM were used (February 1991 to January 1992). A cohort, Group C, consisted of patients (n=73), found only in Group A, scheduled as a 3rd and 4th operative case in the same day. RESULTS: There were no significant differences in demographic and clinical characteristics, the duration of ICU stay or hospital discharge between groups A and B. The surgical or technical staff did not change, and the nurse to patient ratio remained constant. Median total bypass time was significantly greater in Group B (80 vs 73 min in Group A, p<0.05), but the frequency of mortality within the first 14 postoperative days was nevertheless lower in Group B than in Group A (3.3% vs 4.6%, respectively, p<0.05). Recurrent myocardial infarction, postoperative bleeding, arrhythmia, pulmonary embolism, acute renal failure, and duodenal ulcer were also significantly higher in Group A compared to Group B (p<0.05). The excess in postoperative complications could be attributed mainly to Group C. Overall, the relative risk for morbidity and mortality decreased when a second CPBM was implemented (p<0.001). CONCLUSIONS. Postoperative complications in our unit were significantly reduced by acquisition of a second CPBM permitting two cases to be started concomitantly early in the day. This data may be valuable to guide decision analysis in departments which need to expand resources in order to cope with the demand of expanding clinical case load.

Aged↗
PubMed1996

Autologous tissue cardiac valve for aortic valve replacement: technical aspects and early results.

BACKGROUND: The known complications of heterograft bioprostheses and homograft valves have renewed the interest in the use of autologous material. A new technique to construct a tissue prosthesis for aortic valve replacement using the patient's pericardium harvested at the time of operation was developed. The glutaraldehyde-tanned pericardium is mounted on a stent requiring no suturing. Intraoperative testing assures adequate valve function. METHODS: The autologous tissue cardiac valve was implanted in 50 patients in the aortic position between March 1994 and May 1995. Echocardiograms were performed in all patients before hospital discharge, at 3 months (41 patients), and at the end of first postoperative year (12 patients). The mean age was 69.8 +/- 5 years (range, 58 to 82 years). Eighty-four percent of patients presented with aortic stenosis and 16% had a combined lesion. Additional cardiac procedures were performed in 21 patients. RESULTS: Aortic cross-clamp time was 72 +/- 19 minutes, and bypass time was 97 +/- 28 minutes. There were three in-hospital deaths, and 2 patients died within the first postoperative year. Predischarge echocardiography demonstrated excellent hemodynamics, with a mean gradient of 20 +/- 8 mm Hg and no or trivial aortic insufficiency in 45 patients. One patient had moderate aortic insufficiency. At first follow-up 36 patients (90%) were in New York Heart Association class I and 4 patients were in class II. Echocardiography showed no evidence of valve failure or degeneration (mean gradient, 17 +/- 5mm Hg; aortic insufficiency = grade 0 [trivial] in 35 patients, grade II in 3 patients, and grade III in 1 patient). Similarly, no degeneration or valve failure with increasing aortic insufficiency was seen in the patients studied at the end of the first postoperative year. CONCLUSIONS: These results demonstrate that an autologous tissue cardiac valve can be manufactured in the operating room without significant additional operating time. Intraoperative testing minimizes the risk of primary failure with aortic insufficiency. Short-term results are encouraging with good hemodynamic performance of the valve and no signs of degeneration. However, long-term durability needs to be demonstrated.

Aged↗
PubMed1995

Aortic valve replacement: is the stentless xenograft an alternative to the homograft? Early results of a randomized study.

From November 1992 to October 1993 we randomized 101 patients over 60 years of age undergoing elective aortic valve replacement, with or without concomitant coronary artery bypass grafting, to receive either a cryopreserved aortic or pulmonary homograft (n = 38) or a stentless porcine aortic valve xenograft (Edwards Prima 2500) (n = 63). The majority of all valves (92%) were inserted freehand in the subcoronary position. Six homografts (16%) were implanted as a free-root replacement and two xenografts (3%) were used as a mini root. There were four in-hospital deaths (4%), three in the homograft group and one in the xenograft group (homograft, 7.9% versus xenograft, 1.6%; p = not significant). Forty-one patients were followed at 3- to 6-month intervals for 9 +/- 2 months (3 to 14 months) and valve pathology was assessed routinely by means of color flow Doppler echocardiography. Two patients in the homograft group developed new aortic insufficiency grade II; all others remained with trivial or no valve incompetence. The mean gradient remained unchanged to immediate postoperative measurements (homograft, 5 +/- 1 mm Hg versus xenograft, 11 +/- 4 mm Hg; p < 0.001). Despite a slightly higher transvalvular gradient, xenografts achieved excellent initial results when compared to homografts. Ease of implantation and freedom from thromboembolism indicate that xenografts can be an acceptable alternative to homografts, particularly in older patients with small aortic annuli. Long-term studies assessing the durability of the xenograft are necessary for final evaluation.

Aged↗
PubMed1995

Aortic valve replacement with cryopreserved pulmonary allografts: five years' follow-up.

Excellent clinical results with pulmonary autografts and experimental evidence that pulmonary valves can withstand the higher stress in the systemic circulation led us to use the cryopreserved pulmonary allograft for aortic valve replacement. From September 1988 until March 1993, 126 consecutive patients (61 +/- 10 years; 74 men and 52 women) underwent aortic valve replacement with a cryopreserved pulmonary allograft. All allografts were inserted freehand in the subcoronary position. There were four in-hospital deaths (3.2%), and 1 patient had severe valvular incompetence immediately postoperatively, requiring reoperation after 4 weeks. One hundred twenty-one patients were followed up in 3- to 6-month intervals for 25.3 +/- 16.3 months (range, 6 to 66 months), and valve performance was assessed routinely by means of color-flow Doppler echocardiography. Nine patients (7.1%) died during follow-up. Two patients died of multiple septic emboli during bacterial endocarditis, and 1 patient died of a massive stroke. The other 6 patients died of myocardial infarction (4), respiratory insufficiency due to chronic obstructive lung disease (1), and carcinoma (1). Ninety-four patients (78%) had absent or trivial aortic valve regurgitation. Valvular incompetence class II was present in 3 patients (2.5%), whereas 5 others (4%) demonstrated class II to III. Severe aortic regurgitation (class III or IV) could be detected in 10 patients (8.3%). All underwent reoperation and replacement of the valve with a prosthetic device. Bacterial endocarditis caused graft incompetence in 3 patients, valve degeneration was detected in another 3, and technical mistakes at valve implantation caused valve failure in the other 4.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMed1995

[Heart surgery in the elderly].

The number of octogenarian patients undergoing an open heart procedure in our unit is the fastest increasing group of patients. Between June 1985 and July 1994 112 octogenarians (mean age 81.7 years, 60 males, 52 females) underwent cardiac operations. The postoperative course was uneventful in 90 patients (80.4%). The perioperative mortality rate was 8.9% (10 patients). Mortality was lowest in the group receiving aortic valve replacement, with one death out of 30 patients (3.3%). The cause of death was left- or biventricular heart failure in more than half of the fatalities. Postoperative complications included: AV-block III (n = 1), postoperative bleeding (n = 2), unstable sternum (n = 3), acute cholecystitis (n = 1), low cardiac output syndrome (n = 1), stroke (n = 1), pneumothorax (n = 2) and urinary tract infections (n = 1). We consider open heart procedures in octogenarians, despite a mortality rate of 8.9%, as justified. According to the severity and course of clinical symptoms and the type of surgery required, selection of patients for operation should be decided on at an early stage of the disease. Not only life expectancy increases, but there is also a significant increase in life quality for these patients.

Aged↗
PubMed1994

[Use of autologous femoral vein in superior vena cava thrombosis. Case report and review of the literature].

We report on a 52-year old male patient who underwent implantation of an insulin pump because he had diabetes and in whom superior vena cava syndrome developed as a long-term complication. After unsuccessful lysis therapy superficial femoral vein was implanted to form a bypass from the internal jugular vein to the right atrium. The postoperative course was uneventful from the aspects of both the bypass and the leg after explantation of the superficial femoral vein. The bypass is still patent 7 months after the operation, and the patient has no symptoms. Autogenous superficial femoral vein can be used successfully in the reconstruction of large venous vessels. It should be the graft of choice for young patients with benign diseases. We compare our result and those obtained with different substitutes described in the literature that have been used for reconstruction in superior vena cava syndrome.

Femoral Vein↗
PubMed1994

Mycotic aneurysms of the thoracic aorta.

Between February 1982 and December 1992 we operated on five patients (three men, two women; aged 40 to 70 years) with mycotic aneurysms of the thoracic aorta. One patient had an aneurysm of the ascending aorta, once the aortic arch and in three cases the descending thoracic aorta were involved. In four of the five patients, excision of the aneurysm and in situ reconstruction of the aorta with a Dacron graft was performed, one patient required a Dacron graft repair and aortic valve replacement. We employed deep hypothermia with circulatory arrest (2), extracorporeal circulation (1), an axillofemoral shunt (1) and a centrifugal pump (1) for cerebral and spinal cord protection. One patient died 4 months postoperatively, the other four patients were without recurrent graft infection and are free of symptoms between 20 months and 5 years postoperatively.

Adult↗
PubMed1994

The octogenarians--a new challenge in cardiac surgery?

The per- and early postoperative outcomes of 75 consecutive octogenarians (38 male, 37 female, mean age 81.7 years) who underwent open heart surgery were analysed to identify independent variables of risk factors influencing morbidity and mortality. There were 48 coronary bypasses. 20 valve replacements, and 7 combined procedures. Multivariate analysis revealed that functional class (New York Heart Association), operative procedure, aortic cross clamp time, total bypass time, and age are independent predictors for morbidity and mortality (p < 0.05). There were 6 postoperative deaths (8%). Postoperative complications included haemorrhage (2), stroke (1), unstable sternum (2), acute cholecystitis (1), pneumothorax (2), and urinary tract infection. It is concluded that octogenarians may benefit from open heart surgery at an acceptable risk.

Aged↗
PubMed1994

Coronary disease and tracheal stenosis with tracheo-oesophageal fistula: a combined surgical procedure.

A patient with coronary disease class III of the New York Heart Association and tracheal stenosis with a tracheo-oesophageal fistula, which developed after long-term intubation, is described. As both conditions were symptomatic, an aortocoronary double bypass was combined with resection of the trachea and closure of the fistula. Postoperative recovery was uneventful and the patient is symptom-free after 3 years.

Adult↗