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Biomedical subjects

B Kipfer

Publications and source records attributed to B Kipfer.

34 records · Page 2Linked to original sources
PubMed1998

Definitive cure of recurrent prosthetic endocarditis using silver-coated St. Jude Medical heart valves: a preliminary case report.

Despite progress in the area of antimicrobial treatment and the surgical use of homografts, prosthetic valve endocarditis (PVE) remains one of the most dangerous complications following heart valve replacement. We present the case of a patient treated for acute endocarditis which affected the mitral valve and who developed recurrent PVE and native aortic valve endocarditis. After multiple valve surgery, the infection was controlled following aortic and mitral valve replacement using silver-coated prostheses. The St. Jude Medical (SJM) mechanical heart valve Masters Series with Silzone coating is intended to protect heart valve patients against microbial infection. The Silzone coating is formed by an ion beam-assisted deposition process that incorporates silver into the sewing cuff of the SJM heart valve. It has also been suggested that silver treatment may improve the healing characteristics of the heart valve sewing cuff. This technology may be a valuable option to prevent or cure PVE, in addition to homografts. Although the present patient is an isolated case, it was encouraging to find not only a well-healed mitral valve silver-coated prosthesis but also no persistent or recurrent infection during a nine-month follow up.

Adult↗
PubMed1997

[Acute type B aortic dissection: prognosis after initial conservative treatment and predictive factors for a complicated course].

OBJECTIVE: Today there is still debate concerning the optimal mode of treatment for type B dissection of the aorta. Controversies are mainly due to discordant results regarding survival following medical or surgical treatment. We assessed the early and long-term outcome of acute dissection of the descending aorta after initial conservative treatment. METHODS: Between 1980 and 1995, 225 patients were hospitalized in the medical or surgical department of our institution with the diagnosis of acute type B aortic dissection. 38 patients (16.8%) underwent replacement of the descending aorta within the first week after hospital admission. Primary indications for immediate surgery were rupturing aneurysm in 15 patients, extensive dilatation of the descending aorta in 13, distal malperfusion in 8, and pseudocoarctation syndrome with uncontrollable hypertension in 2. All other patients (n = 187) underwent primary conservative treatment in the intensive care unit, which included appropriate antihypertensive medication. RESULTS: Hospital mortality during and after initial conservative treatment was 17.6% (33/187 patients). Main causes of death were rupture in 14 patients, intestinal malperfusion in 13 and cardiac failure in 3, whereas in 3 patients the cause of death could not be determined. Nine additional patients had to be referred for early surgery during the initial hospitalization because of contained rupture (n = 4), rapidly increasing size of the aorta (n = 2) and suspected intestinal ischemia (n = 3). Hospital mortality after early surgery was 21% (8/38 patients) for the overall time period. After hospital discharge from the initial acute dissection, surgery for chronic dissection was performed in 47 patients, mainly because of expanding descending aortic aneurysm. Hospital mortality was 8% in these patients (4/47). Actuarial survival rates after primary conservative therapy were 76 +/- 5% and 50 +/- 7% after 5 and 8 years respectively. CONCLUSION: Currently, surgery for acute type B dissection is limited to patients with rupturing disease, distal malperfusion or uncontrollable hypertension and pains. Despite aggressive antihypertensive treatment, hospital mortality after primary conservative treatment is still high and a substantial proportion of patients requires surgery during initial hospitalization. Although conservative treatment is recommended in most uncomplicated type B aortic dissections, early surgery should be considered in the following situations: younger patients with 5 cm diameter of the aorta at initial evaluation, as well as those with Marfan syndrome, patients with limited false aneurysm or retrograde dissection into the aortic arch, and those with poor medical compliance or uncontrollable proximal hypertension. Radiographic follow-up for an indefinite period may allow detection of potential late complications and proper planning of elective operations when indicated.

Acute Disease↗
PubMed1997

[Current techniques in heart surgery].

Significant advances in open heart surgery during the last two decades were achieved in the field of the extracorporal circulation and the preservation of the myocardium. In the last few years, new therapeutical tools were introduced to treat patients with coronary artery disease. The transmyocardial laser revascularization (TMR) technique was introduced for clinical investigation 1990. Despite limited experience with this device in selected patients, some conclusions after a short follow-up period are available. Patients treated with TMR have significantly less anginal pain and need fewer hospitalisations. With PET follow-up studies, a better subendocardial perfusion at the expense of the subepicardial perfusion was demonstrated. On the other hand, there was no substantial increase found in terms of ejection fraction in treated patients. Minimally invasive procedures have also gained acceptance during the last few years, especially the minimally invasive coronary artery bypass procedures (MIDCAB). Introduced initially to treat solitary stenoses of the LAD without cardiopulmonary bypass, this procedure is actually often used in conjunction with PTCA for three-vessel disease in selected patients. Due to the different methods used and summarized under the term of MIDCAB, definite conclusions about the advantages of this method are difficult to formulate. There is a trend to reduced patency rates of the IMA bypasses in MIDCAB procedures compared to the conventional technique due to the difficulty with limited access.

Angioplasty, Balloon, Coronary↗
PubMed1997

[Homograft in the therapy of cardiovascular diseases].

Despite considerable progress in prosthetic valve technology, there is actually no ideal artificial heart valve that may be employed in all circumstances, when replacement of a diseased aortic valve is necessary. The choice for optimal valve substitute includes mechanical prosthesis, bioprosthetic xenografts, homografts and pulmonary autografts. More recently an aortic valve sparing operation has been proposed in younger patients presenting with anulo-aortic ectasia. The use of homograft heart valves has now been widely accepted in the treatment of congenital heart defects, as well as for an increasing number of valvular pathologies, especially in infective endocarditis. Heart valve preservation by cryopreservation techniques helps to store the small amount of donor material for special indications without loss of quality, thus permitting elective surgery. In vascular surgery, some concern persists regarding the use of prosthetic material for the treatment of mycotic aneurysms and graft infection. In situ repair with a new vascular prosthesis and resection followed by extra-anatomic reconstruction carry a high peri-operative mortality and substantial morbidity. Cryopreserved vascular homografts represent a valuable alternative in these challenging situations.

Aortic Valve↗
PubMed1997

[Myocardial revascularization in geriatric patients].

The results of percutaneous transluminal coronary angioplasty (PTCA) in 71 patients over 75 years of age were retrospectively analyzed and compared with those of 55 patients aged over 75 who underwent surgical revascularization (CABG) during the same time period (1992-1995). The main indication for revascularization was unstable angina. The clinical success in PTCA patients was 92%, with a lesion success rate of 93%. Major cardiac complications occurred in 5% of patients with an in-hospital mortality of 1%. The mean hospital stay was 4 days. During a follow-up period of 16 (range 1-36) months, 23% of patients treated with PTCA needed repeat revascularization (17% PTCA, 6% CABG) and 4 patients (6%) suffered nonfatal myocardial infarction. In-hospital mortality and complications were higher among the surgically treated patients (mortality 7%, major complications 45%), a fact probably related to their poorer clinical condition preoperatively. Repeat revascularization rate in the surgically treated group was 2%. The long-term mortality rate in both groups was 10%. Among long-term survivors, 92% of patients indicated that revascularization (PTCA or CABG) improved their quality of life. More than 80% led normal lives, and > 90% would undergo a second procedure if needed. In selected patients aged over 75, PTCA has a high immediate success rate with low complications and mortality. Long-term recurrence rate is high, however, and repeat revascularizations are frequent. Patient satisfaction after myocardial revascularization (PTCA or CABG) is excellent and the majority of elderly patients can lead an active and independent life.

Aged↗
PubMed1997

Long-term Doppler echocardiographic follow up in normally functioning aortic St. Jude Medical prosthesis.

BACKGROUND AND AIMS OF THE STUDY: Mean and peak Doppler gradients remain the most frequently used parameters for follow up of prosthetic aortic valves. Gradients that deviate from baseline recordings can lead to uncertainty among physician and patient, especially if symptoms have not completely subsided after surgery, or have recurred. This study aimed to document long-term evolution of mean and peak gradients in patients with stationary clinical symptoms and signs. METHODS: Seventy-six patients (48 men, 28 women), of mean age 56.1 +/- 14.5 years (range: 23 to 82 years) who underwent St. Jude Medical bileaflet prosthesis implantation were followed up for a mean of 3.9 years (range: 1 to 7 years), both clinically and echocardiographically. Evolution of mean and peak gradients, left ventricular function, other valvular lesions and rhythm as well as adequacy of anticoagulation were examined. RESULTS: Mean gradient increased from 12.3 +/- 5.5 to 14 +/- 5.7 mmHg (p = 0.002). Mean gradient increased in 47 patients, decreased in 17 and was unchanged in 12. There was no correlation between left ventricular function, appropriate anticoagulation, left ventricular hypertrophy, age or gender with change in mean or peak gradient. Change in peak gradient correlated excellently (r2 = 0.82) with that in mean gradient. CONCLUSIONS: The range of evolution of Doppler gradients in normally functioning St. Jude Medical prostheses has been defined in this study. Slight long-term increases in mean and peak pressure gradients are normal findings and do not warrant a change in management strategy if unaccompanied by deterioration of symptoms and/or clinical signs. Although we recommend routine determination of baseline flow measurements within three months of prosthesis implantation, mean and peak gradients are adequate follow up parameters. Peak gradient correlated well with mean gradient and may be a useful adjunct for follow up in clinical practice.

Aortic Valve↗
PubMed1996

[Acute dyspnea].

A 75 year old patient was hospitalized because of acute dyspnea. For two weeks she suffered from a flu-like illness with low-grade fever, cough, and fatigue. On auscultation systolic and diastolic murmurs were found whose intensity changed depending on the position assumed by the patient. Transthoracic and transoesophageal echocardiography showed a tumor in the left atrium obstructing the left ventricular inflow tract. The tumor was removed surgically because of this obstruction and the imminent danger of embolism to the peripheral arteries. The diagnosis of an atrial myxoma was confirmed intraoperatively and by histology.

Acute Disease↗
PubMed1995

Surgery for acute ascending aortic dissection: closed versus open distal aortic repair.

One hundred twelve consecutive patients with acute ascending aortic dissection and submitted to immediate surgery were retrospectively analyzed with regard to perioperative mortality and morbidity. The patients were divided into two groups according to whether distal aortic repair was carried out by the open procedure (using deep hypothermic circulatory arrest, group A: 68 patients) or by the closed technique (without circulatory arrest, group B: 44 patients). Patients' ages ranged from 24 to 78 years (mean 57.4 years). No significant difference was found between the two groups in terms of age and sex distribution. However, the prevalence in the extent of clinical and anatomical alterations was significantly higher in group A (hemodynamic instability, pericardial tamponade and neurological deficit). The duration of hypothermic circulatory arrest for group A patients averaged 25 min and ranged from 12 to 65 min. The overall perioperative mortality was 17% (19/112 patients); it was 20.6% (14/68) in group A and 11.4% (5/44) in group B; the difference was not statistically significant but consistent with a clear trend. The trend towards a higher mortality in group A mainly reflected the more severe and complex anatomical characteristics and could not be attributed to the circulatory arrest per se. The period of deep hypothermic circulatory arrest in the survivors (25 min) was similar to that of the group with lethal outcome (32 min). Among the non-lethal complications, however, group A patients more frequently showed clinical signs consistent with cerebral injury: apart from the transient symptoms suggestive in reversible diffuse cerebral damage, five patients in group A had a permanent focal neurological deficit (versus one patient in group B).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1995

[Non-Hodgkin's lymphoma with heart, mediastinum and lung hilar involvement].

We performed an exploratory thoraco-, pericardio- and cardiotomy in a 70-year-old male patient suffering from a biatrial tumor after a thorough diagnostic procedure had failed to reveal the correct diagnosis. Histologically, the tumor proved to be a centrocytic-centroblastic non-Hodgkin-lymphoma. This case demonstrates the diagnostic difficulties in cardiac involvement of lymphomas and presents the therapeutic options.

Aged↗
PubMed1994

Acute traumatic rupture of the thoracic aorta: immediate or delayed surgical repair?

The appropriate management of traumatic aortic rupture is often difficult to determine, particularly if the rupture is associated with severe additional lesions. Between 1986 and 1991, ten consecutive patients with acute traumatic rupture of the thoracic aorta (ATRTA) and concomitant injuries were initially treated medically and submitted to delayed aortic repair. Within the same period no other patient had emergency reconstruction of the thoracic aorta. Diagnosis of ATRTA was established immediately after admission in eight patients. Five patients underwent emergency surgery for severe concomitant injuries. With regard to the aortic lesion, all patients were managed medically and submitted to pharmacological treatment in an attempt to reduce cardiac shear forces. None of the patients developed clinical signs of imminent free rupture while waiting for aortic surgery. In the absence of a significant hemothorax and when no coarctation syndrome is evident, the risk of free aortic rupture is considered to be rather low if the patient reaches the hospital in a stable circulatory condition. Postponement of aortic reconstruction is particularly indicated when severe concomitant lesions preclude safe immediate repair of the aortic tear. Following the patient's recovery from associated major injury, aortic surgery can be performed as a low risk procedure using cardiopulmonary bypass which is recognised as the most effective technique to prevent spinal cord ischemia and to reduce the risk of paraplegia.

Acute Disease↗
PubMed1994

Hemofiltration during cardiopulmonary bypass: quality assessment of hemoconcentrated blood.

UNLABELLED: Hemofiltration is often used during cardiopulmonary bypass (CPB) for water removal. In a prospective random study 11 patients undergoing elective coronary artery surgery with hemofiltration during CPB were observed and compared to 11 patients without filtration. The quantitative and qualitative aspects of blood before and after filtration while still on CPB and until the first postoperative day were assessed. Intra- and postoperative volume requirements, standard hematology and chemistry, as well as hemolysis, complement activation, and coagulation factors were analysed at nine sequential points in time. RESULTS: There were no significant differences in pre- and postoperative patient data between the two groups except that the majority of patients in the study group (55%) were anticoagulated and required a significantly longer CPB time with higher doses of protamine and had higher postoperative drainage (2.9 vs. 1.4 L). Intra- and postoperative hemoglobin concentrations, transfusion and volume requirements were similar in both groups. 927 ml of plasma water were filtered during CPB within 4 min 20 s without hemodynamic changes or electrolyte imbalance. Hemoglobin and protein concentrations increased significantly during hemofiltration (Hb increases 3.6 g/dl). Hemolysis and activated complement fractions were elevated during CPB but showed no further increase during filtration; in contrast C4a, C5a, and prothrombin F1 + 2 increased significantly after cessation of CPB. In conclusion, hemofiltration during CPB is a safe and efficient method for water removal and for concentration of red blood cells and proteins without adverse effects on the patient's hemodynamics, blood quality, and volume requirements. More especially, no negative influence of hemofiltration could be determined with regard to activation of the coagulation and complement system.

Blood Cell Count↗
PubMed1993

Impending rupture of the ascending aorta due to giant cell arteritis.

Giant cell arteritis may occasionally lead to vessel perforation without previous dissection. At the level of the ascending aorta, however, such an event has been reported only three times. We report a fourth case of impending rupture of the ascending aorta due to a small and isolated lesion of giant cell arteritis. In contrast to previous reports, laboratory and clinical manifestations suggestive of giant cell arteritis were absent in this case so that the diagnosis could only be established on histologic examination of the operative specimen.

Aortic Rupture↗
PubMed1993

[Therapy of pulmonary arteriovenous aneurysm].

Connections of branches of the pulmonary artery to branches of the pulmonary vein resulting in aneurysmatic dilatation are defined as pulmonary arterio-venous aneurysm (pava). The spontaneous course shows a morbidity of 26% and a mortality of 11% within a six-year observation period following diagnosis. If there is an arterial branch with small diameter (< 15 mm) we recommend the embolisation with the catheter; this procedure is less stressing for the patient and does not involve the loss of pulmonary tissue. If the arterial branch has a big diameter, if a complex pava or a pulmonary abscess is present a conventional surgical resection should be envisaged.

Adult↗
PubMed1990

[Heart and vascular surgery interventions with hypothermic circulatory arrest in adults].

In the period between 1981 and 1988, 51 patients were operated on the thoracic aorta using the hypothermic circulatory arrest technique. 31 patients had a dissection of the thoracic aorta, in 16 cases, an aneurysm was the reason for the intervention. In addition, we used the hypothermic circulatory arrest for a thrombectomy in the aortic arch and two mitral-valve replacements. The following operations were performed: 14 x composite graft, 19 x supracoronar prosthesis (6 x with aortic valve replacement, 3 x with partial replacement of aortic arch), 17 operations were performed either for aortic arch or aorta descendens replacement. In our retrospective study, 7 courses were fata (14%), 3 patients had complications with residuals. Compared with a group of 105 patients operated on the thoracic aorta in the same period without circulatory arrest, we found no difference with regard to the lethality and morbidity. We conclude that the hypothermic circulatory arrest is a safe technique for selected problems in cardiovascular surgery in adults.

Aortic Dissection↗