Search PubMed⌕ Search

Biomedical subjects

H Dalichau

Publications and source records attributed to H Dalichau.

At least 37 records · Page 2Linked to original sources
PubMed2000

Preimplant ultrastructure and calcification tendency of various biological aortic valves.

BACKGROUND AND AIM OF THE STUDY: In recent years a number of fixation and anti-calcification methods have been developed, but little is yet known about the calcification process of biological valves. The aims of this study were to: (i) perform a systematic ultrastructural investigation on various biological valves; and (ii) determine the extent of calcification of these valves in a subcutaneous rat model. METHODS: The following porcine aortic prostheses were investigated: Toronto-SPV, Intact, Freestyle, Mosaic and Hancock-II. Samples taken from the valve leaflets, and in the case of the Freestyle and Toronto-SPV valves also from the aortic wall, were examined ultrastructurally using scanning and transmission electron microscopy. Other samples were implanted subcutaneously in Wistar rats for 12 weeks. The calcium content of the samples was measured using atomic absorption spectrophotometry. RESULTS: All valves examined showed a considerable loss of the endothelial cover. Significant changes in valve ultrastructure were also detected. With regard to calcium content, two valve groups could be distinguished (p <0.05): (i) those with high calcium content, e.g. Toronto-SPV and Intact (>40 mg/g dry tissue); and (ii) those with low calcium content, e.g. Mosaic, Freestyle and Hancock-II (<5 mg/g). CONCLUSION: Fixation methods have pronounced effects on the ultrastructural integrity of bioprostheses. The degenerative calcification of bioprostheses can be effectively inhibited by glutaraldehyde-free fixation and anti-calcification treatments.

Animals↗
PubMed2000

Chyloperitoneum. A rare complication after abdominal aortic aneurysm repair.

We report a case of chylous ascites as a rare complication following elective aortic aneurysm repair in a 66-year-old male. After its early development on the second post-operative day, re-laparotomy was performed with ligation of fistulas and omentumplasty. After recurrence of chylous ascites, conservative treatment for three months including parenteral nutrition and low-fat diet under continuous peritoneal drainage led finally to success.

Aged↗
PubMed1999

[Traumatic pulmonary hernia].

The traumatic pulmonary hernia is a rare and uncommon observation. We report a case of a 52-year-old patient who had a car accident. Beside multiple polytraumatic injuries we were able to diagnose an incarcerated pulmonary hernia. Hernia size, incarceration and the respiratory insufficiency of the patient necessitating immediate surgical intervention. We relocated the hernia into the chest and stabilized the thoracic wall. The postoperative course was uneventful.

Female↗
PubMed1999

Unsuspected idiopathic mediastinal fibrosis complicating coronary bypass operation.

A 66-year-old woman was referred for coronary bypass operation to the left anterior descending and the circumflex arteries. She had a systemic inflammatory process of unknown origin. On opening the pericardium, fibrotic plaques encircling the entire ascending aorta were found. Aortic cannulation and proximal anastomosis of the planned vein graft were impossible. The right internal mammary was anastomosed to the left anterior descending artery, the left to the obtuse marginal after femoral arterial cannulation. Pathologic examination revealed idiopathic mediastinal fibrosis.

Aged↗
PubMed1999

Leiomyosarcoma of the diaphragm.

An asymptomatic, intrathoracic mass was found on imaging studies in a 53-year-old man. After excision it proved to be an extrapulmonary leiomyosarcoma, a rare malignancy of smooth muscle, originating from the right diaphragm. The location of this malignant tumor is rare in an adult. The tumor was resected, the diaphragm was reconstructed, and the patient should have a long-term cure and good quality of life.

Diaphragm↗
PubMed1999

Calcification tendency of various biological aortic valves in an experimental animal model.

The present study aimed at investigating the influence of fixation methods on the ultrastructure and calcium content of five different aortic biovalves. Biovalves subcutaneously implanted in Wistar rats for 12 weeks demonstrated significant differences in their calcium contents. Using Scheffe tests, two different groups of biovalves could be distinguished: (i) valves with high calcium content, such as Toronto-SPV (165 +/- 42 mg/g dry tissue) and Intact (193 +/- 36 mg/g dry tissue), and (ii) valves with low calcium content, such as Mosaic (2.7 +/- 1.8 mg/g dry tissue), Freestyle (2.3 +/- 1.1 mg/g dry tissue) and Hancock-II (3.6 +/- 1.2 mg/g dry tissue) (P < 0.05). All biovalves with an ultrastructurally preserved endothelium exhibited a low calcification tendency. The data suggest that if the endothelium is lost as a result of the fixation procedure, then calcification can only be prevented by appropriate anticalcification methods.

Animals↗
PubMed1999

Giant primary cardiac liposarcoma vascularized via the circumflex coronary artery.

A 51-year-old patient presented with a history of chest pain and progressive dyspnea. CT scan demonstrated a lipomatous mass encircling the heart and compressing the left lung. After median sternotomy, an intrapericardial tumor of 3200 g with a vascular pedicle arising from the circumflex coronary artery was resected. A histologic diagnosis of a well-differentiated liposarcoma was made. The patient is alive and well 2 years postoperatively. This tumor with its unusual vascularization is the largest of the few primary cardiac liposarcomas that have been reported.

Cardiac Surgical Procedures↗
PubMed1999

Combined approach for internal carotid artery stenosis and cardiovascular disease in septuagenarians--a comparative study.

OBJECTIVE: The best surgical approach for concomitant carotid artery and cardiac disease remains controversial. Many studies proved the safety and efficiency of simultaneous surgery. We aimed to demonstrate the same benefits for patients > or = 70 years. METHODS: We retrospectively evaluated 205 patients simultaneously operated upon between 1988 and 1998. Group A comprised patients < 70 years (n = 110), group B > or = 70 years, (n = 95). Risk factors, neurologic and cardiac history, angiographic findings, operative data, morbidity and mortality (30-day-postoperatively) were analysed. The mean age was 62 years in group A and 75 years in group B. All patients with symptomatic carotid artery disease, stenosis > 70% or ulcerative carotid disease had simultaneous surgery. Always, the carotid artery was addressed first. RESULTS: Patients in group B had a higher prevalence of peripheral vascular disease (P = 0.0005), renal insufficiency (P = 0.0011) and COPD (P = 0.03). Urgent operation was indicated in 19% of group A patients vs. 37% in group B. In group A 70% were asymptomatic regarding the carotid vs. 48% in group B. Left ventricular dysfunction was present in 45% (group A) and 58% (group B). In the present study 4% in group A and 7% in group B suffered a perioperative myocardial infarction. Pathologic changes of the contralateral carotid were found in 42 vs. 57% (A vs. B). Mortality due to cardiac causes was 1 and 5%, respectively. The combination of persistent neurologic deficit and neurologic death occurred in 3% in group A (n = 3) and 5% in group B (n = 5). Postoperative neuro-cognitive dysfunction was more common in group B (35 vs. 16%; P = 0.01). CONCLUSIONS: The incidence of persistent neurologic deficits and neurologic mortality in patients > or = 70 years is acceptable, and low in patients < 70 years. Preoperative risk factors are increasing with age and are related to the higher mortality in elderly patients. Due to our results we will conclude that the combined approach for carotid stenosis and cardiovascular disease is the method of choice in this high-risk population.

Aged↗
PubMed1999

[Deep leg and pelvic vein thrombosis in aplasia of the inferior vena cava].

Deep phlebothromboses of iliacal vein and aplasia of the inferior vena cava Coincidence of deep phlebothromboses of iliacal vein and aplasia of the inferior vena cava is a rare condition but has significance for further therapy. Two cases of this anatomical malformation with complications are presented and the importance of therapeutical strategies are discussed. We report on our experiences with the operative procedures of venous thrombectomy and arteriovenous fistula, aimed at increasing the venous flow in the collaterals of the aplastic inferior vena cava.

Adult↗
PubMed1999

Incidence and importance of lower extremity nerve lesions after infrainguinal vascular surgical interventions.

OBJECTIVES: To determine the incidence of peripheral nerve lesions after arterial vascular surgery of the lower extremity. MATERIALS AND METHODS: 436 patients who underwent peripheral vascular surgery from January 1992 until December 1996 underwent a detailed postoperative neurological examination. RESULTS: 147 patients underwent profundaplasty, 140 above-knee femoropopliteal bypasses, 106 below-knee femoropopliteal bypasses and 56 femorotibial bypasses. There were 182 women and 254 men. Peripheral nerve lesions were observed in 11 patients (4%) after primary operations. 166 patients underwent reoperations (38%) and 55 of these developed nerve lesions (33%). CONCLUSIONS: Reoperation carries an 8-fold increased risk of nerve lesions compared with patients undergoing primary surgery. Detailed explanation of the risk of peripheral nerve lesions before vascular surgery of the lower limb is advisable.

Aged↗
PubMed1999

Experiences with the Toronto SPV bioprosthesis after three years follow-up.

BACKGROUND: Stentless aortic valve prostheses are considered to be hemodynamically superior to mounted bioprostheses. The Toronto SPV bioprosthesis is a Dacron covered stentless porcine aortic prosthesis. METHODS: From March 1993 to October 1997, 175 patients underwent aortic valve replacement with the Toronto SPV bioprosthesis, 126 patients with leading aortic stenosis, 14 with valve insufficiency, and combined lesion in 35 patients. Preoperatively all patients were in NYHA class III-IV. All patients underwent transesophageal echocardiography (TEE) intraoperatively after institution of cardiopulmonary bypass (CPB). The patients underwent clinical and echocardiographic examinations at 1 week, 6 months, 12 months, 24 months, and 36 months postoperatively. RESULTS: Mean age was 71.3 years (range 29-84). Additional coronary artery bypass grafting (CABG) was performed in 74 patients. Mean ischemic time was 58 minutes (range 49-129) for singular aortic valve replacement (AVR) and 86 minutes (range 66-136) with additional CABG. The 30-day mortality was low at 4% (7/175). 139 patients were seen at 2 years and 77 at 3 years follow-up. At 3 years 67% (51/77) of our patients were in NYHA functional class I and 33% (26/77) were in class II. Minimal aortic valve incompetence was seen in 17% (13/77) at 3 years. CONCLUSIONS: The Toronto SPV bioprosthesis shows good results both hemodynamically and clinically. Most patients are in NYHA functional class I or II after 3 years. Perioperative mortality was low and no valve-related complications occurred.

Adult↗
PubMed1999

Chest re-exploration for complications after lung surgery.

BACKGROUND: Review of the most recent chest re-explorations for lung surgery complications may show methods by which risks can effectively be reduced. METHODS: The data on rethoracotomies following lung surgery over the past 14 years in our department were retrospectively reviewed. The indication, the type of operation, the outcome, and various factors influencing the postoperative mortality were analyzed. From 1983 to 1996, 1960 patients underwent primary thoracotomies for various lung diseases. Among these, 73 (3.7%) patients required re-exploration for various postoperative complications. RESULTS: Mean age was 56.8 years (15-80 years). There were 66 (90.4%) men and 7 (9.6%) women. The most common indication for rethoracotomy was hemorrhage in 38 (52%) patients. The source of bleeding was a mediastinal and/or bronchial blood vessel in 8 patients and an intercostal blood vessel in 6 patients. Six patients had to be reoperated because of hemorrhage from a major artery of the hilus. In 14 cases the postoperative hemothorax occurred without evident surgical origin. Further indications for rethoracotomy were bronchopleural fistula (BPF) in 13 (17.8%) patients, and persistent parenchymal leak in 8 (10.9%) patients. There were 8 additional causes distributed among the remaining 14 (19.3%) patients. The overall mortality rate was 17.8% (13/73), with the highest (38.4%) among BPF patients. CONCLUSIONS: Postoperative complications following lung surgery which require rethoracotomy are rare. The most common complication is postoperative bleeding. This is followed by bronchial stump insufficiency which is associated with the highest mortality and morbidity. Our experience shows that the need for re-exploration can hardly be reduced but the indication for re-exploration should be established as early as possible to avoid late complications.

Adolescent↗
PubMed1999

Heart transplantation after successful donor postpartum pulmonary embolectomy.

A fulminant pulmonary embolism can be treated surgically if thrombolytic therapy is contraindicated. A 31-year-old woman developed a fulminant pulmonary embolism after right-sided deep venous thrombosis 1 day after undergoing a cesarean section. A pulmonary embolectomy with cardiopulmonary bypass was performed, but the patient was brain-dead. After 2 days of echocardiographic observation, her heart was explanted for a 61-year-old man with ischemic cardiomyopathy. His right heart data were unremarkable, and he remains well 16 months after transplantation. Despite the sudden strain on the right ventricle that occurs with a pulmonary embolism, such a heart may be transplanted successfully after a pulmonary embolectomy.

Adult↗
PubMed1999

Coronary artery bypass procedures in septuagenarians are justified. Short and long-term results.

BACKGROUND: Elective coronary artery bypass surgery can be performed with low operative mortality. There is a controversial discussion whether short-term and long-term results of CABG justify this procedure in elderly patients. METHODS: To add to this discussion, we evaluated retrospectively, the clinical profile, operative technique, short- and long-term results of 1127 patients over 70 years of age who underwent myocardial revascularization between January 1985 and December 1996. RESULTS: Mean age of the cohort was 73.9 years and it rose continuously. In 1996, septuagenarians represented 21.5% of our coronary patients, in comparison to 6.4% in 1985. Analysis of risk factors showed an increasing prevalence of renal failure, obesity, hyperuricemia and a history of smoking. Preoperatively, 87% of our patients were in NYHA-class III or IV, and thus operated to relieve severe symptoms. The percentage of emergent operations decreased over the observed period by 10.3%. The internal mammary artery was used with rising frequency (44.8% in 1985-1992 vs 61.5% in 1993-1996). The number of simultaneous valve replacements increased, too. Postoperatively, we noted a rising incidence of respiratory failure (17.1%) and neurological disorders (13.7%). On the other hand, the need for intra-aortic balloon pumping and hemofiltration declined by 6.6% and 2.9%, respectively. Perioperative mortality (< or =24 hrs) was 3.65%, hospital mortality (< or =30 days) was 9.64%. The actuarial survival (standard error) at 1 year was 82% (+/-4.3%), and 65.7% (+/-3.8%) at 5 years. CONCLUSIONS: Our data suggest that coronary artery bypass grafting can be performed in septuagenarians at an acceptable risk. Since the large majority of patients improve symptomatically, surgery is a recommendable option for a growing number of elderly patients suffering from severe angina.

Aged↗
PubMed1999

Mitral valve replacement through dilated aortic annulus in Marfan's syndrome.

A 30-year-old man presented with severe aortic regurgitation due to an ascending aortic aneurysm and mitral valve insufficiency in conjunction with active endocarditis. He underwent combined aortic root replacement by a composite graft and mechanical mitral valve replacement. After excision of the aortic valve cusps the mitral valve was approached through the extremely dilated aortic annulus. This technique is seldom used. Mitral valve replacement through the aortic root can be advantageous in selected patients to minimize trauma and reduce myocardial ischemic time.

Adult↗
PubMed1999

Development of cardiovascular procedures before abdominal aortic aneurysm repair over 16 years.

INTRODUCTION: Preoperative screening, interventional and surgical therapy of cardiovascular diseases are of pivotal importance for a successful outcome after abdominal aortic aneurysm (AAA) surgery. METHODS: In a retrospective study all patients who underwent surgery for AAA were reevaluated for preoperative diagnostic and therapeutic interventions for cardiovascular diseases. Two study periods 1980-1989 and 1990-1996 were defined. Of 603 patients operated upon because of AAA between 1980 and 1996, 449 were operated on an elective basis and 154 as an emergency. Preoperative diagnostic studies for coronary artery disease (CAD) were performed in electively operated patients only and were positive in 76.8% (1980-1989: 76.1%, 1990-1996: 77.5%). Coronary angiography was performed in 108 patients (29.6%). Medical therapy of CAD declined by 2.3%, interventional procedures by 18.8%. In contrast, myocardial revascularization with subsequent aneurysm resection increased by 26. 6% and 12 patients (16%) required urgent simultaneous cardiac and aortic surgery. Early mortality after AAA surgery dropped from 4.2% to 2.9%, the frequency of primary cardiac failure as the cause of death was reduced from 33.3% to 22.2% (p < 0.05). CONCLUSIONS: 42.6% more cardiac surgical procedures were performed before AAA surgery since 1990 compared with the period 1980-1989. In contrast, the number of interventional procedures fell by 18.8%. Surgical therapy of cardiac disease reduces early mortality after elective AAA surgery.

Aged↗
PubMed1999

Incarcerated postraumatic intercostal lung hernia. Case report and review of the literature.

Traumatic lung hernia is a rare diagnosis. A 52-year-old female motorvehicle passenger was admitted as a trauma patient after a motorvehicle accident. She was found to have an incarcerated lung hernia. Size of the hernia, incarceration and respiratory insufficiency mandated immediate surgical intervention with reposition, drainage and stabilisation of the chest wall. The postoperative course was uneventful. The management of the patient is discussed and the available literature reviewed.

Female↗