Biomedical subjects

A M Fabricius

Publications and source records attributed to A M Fabricius.

10 recordsLinked to original sources

PubMed2003

[Surgical treatment of therapy resistant atrial fibrillation].

Atrial fibrillation in patients with isolated, therapy resistant, chronic or paroxysmal atrial fibrillation (AF) or AF in combination with additional valvular and non-valvular cardiac pathology can be surgically treated by different techniques. Unipolar high frequency, cryotherapy and microwave energy is a curative approach for the treatment of the left atrium for AF. The postoperative mortality and morbidity rate is comparable to other cardiac surgery procedures. It is a technically less challenging procedure as compared to the MAZE procedure and can be applied using a minimally invasive approach. Alternative techniques such as new cryotechnologies, laser application and bipolar high frequency energy need to be evaluated for effectiveness and safety.

Atrial Fibrillation↗

PubMed2003

Epicardial treatment of atrial fibrillation using cryoablation in an acute off-pump sheep model.

BACKGROUND: The purpose of this study was to test the feasibility and effectiveness of cryoablation therapy (SurgiFrost trade mark CryoCath, Endocare Inc., Irvine, California, USA) for linear epicardial treatment of atrial fibrillation in an acute off-pump sheep model. METHODS: After thoracotomy, we performed epicardial cryoablation (2 min intervals at -160 degrees C) with pacing electrodes positioned at the left atrial appendage (LAA), the pulmonary veins (PVs), the right atrial appendage (RAA), and the vena cava cranialis (VCC) in 8 sheep. Circular epicardial ablations were performed with online temperature measurement in the ascending aorta and in the esophagus. The sheep were sacrificed two hours after ablation procedure, and heart, lungs, and esophagus were retrieved for histological examination. Out of all 8 sheep, histo-pathological analysis was performed on the RAA and VCC in 6 sheep and on the CAA and PV in all 8 sheep. RESULTS: Thin-walled structures such as PVs and VCC showed electrical isolation. No significant changes in temperature in the descending aorta and the esophagus were observed. There was evidence of extensive transmural alteration including vascular lesions, myocardial degeneration and necrosis as well as epi- and endocardial necrosis in the left atria in three of 8 cases, in the right atria in 5 of 6 cases, in the VCC in 6 of 6 cases, and in the PV in 5 of 8 cases. Mild lesions of the muscular layer of the esophagus were found in 7 of 8 cases. CONCLUSIONS: Epicardial cryoablation is not effective on thicker tissues like LAA and RAA due to the rewarming of the current blood flow. However, thin tissues like VCC and PV can be isolated. Further chronic studies are necessary to evaluate the potential for regeneration of adjacent structures.

Animals↗

PubMed2002

Comparison of ultrasonic scalpel versus argon-beam and conventional electrocautery for internal thoracic artery dissection.

BACKGROUND: We used an ultrasonic scalpel (USS) and an argon beam coagulator (ABC) to test their effectiveness and feasibility in comparison to conventional electrocautery for Internal Thoracic Artery (ITA) takedown, time for takedown, number of clips, thermal impact, along with morphological integrity assessed by histology. PATIENTS AND METHODS: Ninety-three patients undergoing elective coronary bypass surgery were prospectively randomized into three groups. In thirty-one patients, either an ultrasonic scalpel (USS, group A), an argon-beam coagulator (ABC, group B) or conventional electrocautery (CEC, group C) was used for ITA harvesting. RESULTS: Harvest times for ITA takedown using CEC (16.7 +/- 6 min) was significantly faster compared to ABC (21.6 +/- 8.1 min; p = 0.02) and USS (24.1 +/- 8.1 min; p < 0.001). There was no significant difference comparing harvest times of USS and ABC (p = 0.1). The number of hemostatic clips used was significantly lower when using USS (5.5 +/- 4.6 clips) compared to both CEC (16.6 +/- 6.2 clips; p < 0.001) and ABC (20.4 +/- 6.5 clips; p < 0.001) and significantly lower using CEC compared to ABC (p < 0.007). There were no significant differences in bleeding points within the tissue bed among the groups (ABC 11/31 patients, CEC 11/31 patients and USS 12/31 patients). CONCLUSION: This study demonstrates that dissection of the ITA pedicle can be safely done with USS, ABC, and CEC. However, USS is associated with less hemostatic clip demand but prolonged harvest time compared it to ABC and CEC; histological assessment revealed no significant difference when comparing groups and equipment used. A variety in design of the hooks may probably ease ultracision practicability.

Aged↗

PubMed2001

Early angiographic control of perioperative ischemia after coronary artery bypass grafting.

OBJECTIVE: To assess the impact of immediate angiography in patients with defined clinical and laboratory criteria of perioperative myocardial infarction after coronary artery bypass operation. PATIENTS AND METHODS: Between January 1999 and December 1999 2052 patients underwent coronary artery bypass grafting in our institution. Out of this cohort 131 (6.4%) patients met the criteria of perioperative myocardial ischemia, which was defined as: (a) increase in the isoenzyme ratio of creatinine phosphokinase (CK/CK-MB] above 10%; (b) ischemic electrocardiographic episodes (defined as a new onset of elevated ST-segment change lasting at least 1 min and involving a shift from baseline of greater than or equal to 0.1 mV of ST-depression and a new association of a postoperative Q; (c) recurrent episodes of, or sustained ventricular tachyarrhythmia as well as ventricular fibrillation; (d) hemodynamic deterioration despite adequate inotropic support. RESULTS: Angiography was performed in 108 patients (5.3%, group A) whereas 23 patients (1.1%, group B) were immediately re-operated due to severely compromised hemodynamics. Angiographic results in group A showed regular grafts in 45 patients (2.2%); 63 patients (3.1%) had either an occlusion (n=41), incorrect anastomosis (n=29), graft stenosis (n=14), graft spasm (n=6), displaced graft (n=6), poor distal run-off (n=5) or incomplete revascularization (n=2). In group A 43 patients underwent a re-operation (34 patients) or an early angioplasty (nine patients). Due to poor coronary artery status no intervention was performed in the remaining 20 patients with angiographic findings. Operative findings in group B showed graft occlusion in ten patients (43.5%), incorrect anastomosis in five patients (21.7%), bleeding, stretched graft, venous graft spasm and displaced graft in one patient (4.3%) each, and no patho-morphological finding in 4 patients (17.4%). Thirty-day mortality rate was ten patients in group A (9.3%), all of them with angiographic findings, as opposed to nine patients (39.1%) in group B. CONCLUSION: ST-change and elevated CK/CK-MB enzyme ratio is highly indicative for possible graft failure and should be followed early angiographic control to assess the need for reintervention.

Adult↗

PubMed2001

Floating thrombus on an ASD occluder device in a patient with hemophilia A.

The case presented is that of a 29-year-old man with a history of hemophilia A who was admitted with recurrent onsets of transient cerebrovascular ischemia; he had undergone a transvenous closure of an atrial septal defects with an occluder device (Cardioseal Starflex) two months ago. Due to a factor-VIII deficiency, no further anticoagulation therapy was initiated. On admission, transesophageal echocardiography revealed a floating thrombus on the left atrial side of the umbrella. The device was explanted via a right minithoracotomy, and the atrial septal defect was closed. The patient had an uneventful recovery.

Adult↗

PubMed2001

Acute aortic dissection during pregnancy.

We review the cases of two women with acute aortic dissection during their last trimester of pregnancy who underwent aortic root replacement. One patient with type A dissection had to undergo surgical intervention immediately, and required extracorporal membrane oxygenation for four days. The other patient with a pre-diagnosed Marfan's disease had suffered a type B dissection and had to undergo emergency operation after developing a type A dissection nine days later.

Adult↗

PubMed2000

Minimally invasive saphenous vein harvesting techniques: morphology and postoperative outcome.

BACKGROUND: Conventional saphenous vein harvest is associated with numerous complications, which may be reduced by minimally invasive vein-harvesting techniques. The integrity of the venous endothelium must be guaranteed before using new saphenous vein harvesting techniques. This short-term study compared the clinical outcome of two minimally invasive techniques with the conventional technique, and compared morphology as documented by light and electron microscopy. METHODS: Ninety-two patients were prospectively randomized into three groups. Two different minimally invasive techniques of greater saphenous vein harvesting were used in sixty-two patients. One used a video-assisted dissector (group A, n = 31), and one used a light-coupled retractor (group B, n = 31). Thirty patients were treated by the conventional technique (group C). RESULTS: Incision lengths were 7.6+/-2.1 cm in group A and 9.3+/-3.2 cm in group B, as compared with 38.9+/-8.7 cm in the conventional group. Harvesting time was prolonged by a mean of 26% when using a minimally invasive technique. Conversion rate to the open technique was 3 of 31 (9.3%) in group A and 2 of 31 (6.2%) in group B. No wound complications were noted in group A, but one wound inflammation was seen in group B; only a mild hematoma was seen in both groups. Edge necrosis, wound separation and inflammation were noted in the conventional group. Light and electron microscopy revealed no significant denudation of the endothelial layer in groups A and B as compared with group C. CONCLUSIONS: These data show an excellent postoperative result when using the minimally invasive technique as compared with the conventional group. The safety of the technique is demonstrated by the preservation of endothelial integrity.

Feasibility Studies↗

PubMed2000

Endothelial function of human vena saphena magna prepared with different minimally invasive harvesting techniques.

OBJECTIVES: Minimally invasive saphenous harvesting techniques have been shown to reduce post-operative morbidity. However, when applying new techniques of vein harvesting, endothelial integrity should be preserved in order to guarantee graft quality. We investigated the impact of two different minimally invasive saphenous vein harvesting techniques on endothelial function compared with the traditional 'open' technique by inducing endothelium-dependent in vitro relaxation. METHODS: Two different minimally invasive techniques for harvesting the greater saphenous vein were used in 66 patients, either using a video-assisted dissector (ETHI, n=33) or a light coupled retractor (AUTS, n=33); other patients were treated conventionally (CONV, n=30). The physiological response was tested in vitro using an organ chamber on vein segments exposed to acetylcholine after precontraction with potassium. RESULTS: In both minimally invasive groups, two patients each had to be converted to the traditional open technique and dropped out of the study. The endothelial function of the other veins harvested by either of the minimally invasive techniques showed no significant difference compared with veins harvested conventionally. Reactivity was measured as the percentage relaxation of pharmacological contraction and was significant in all groups (P<0.05); ETHI, 49.1+/-4.2%; AUTS, 48.8+/-5.1%; and CONV, 51.7+/-6. 0%. The responder/non-responder ratio was similar in all groups: ETHI (two drop-outs), 28/3 (90.3%); AUTS (two drop-outs), 28/3 (90. 3%); and CONV, 27/3 (90.0%). CONCLUSION: Veins harvested by minimally invasive techniques have not shown an impaired reactivity of the endothelium compared with the conventional technique.

Endothelium, Vascular↗

PubMed2000

Primary left-atrial leiomyosarcoma.

A patient rapidly developing right heart failure due to a left-atrial leiomyosarcoma was admitted for surgery. A large tumor, originating in the left atrium and extending into both pulmonary veins, was removed. Histology showed an unusual epitheloid appearance of many cells with occasional mitoses and a strong immunexpression to desmin and actin. Six months later heart failure developed again: computer tomography demonstrated regrowth of the tumor in the left atrium with invasion of the mediastinum and the para-aortal lymph nodes. The patient died shortly after.

Aged↗

PubMed2000

Functional and morphologic assessment of saphenous veins harvested with minimally invasive techniques using a modified laryngoscope.

BACKGROUND: Minimally invasive saphenous vein harvesting techniques have been shown to reduce postoperative morbidity. Commercially available and often disposable instruments add significant costs to the operation. To lower expenses and to reduce postoperative morbidity, we used an ordinary laryngoscope fitted with a modified # 3 Heine blade for harvesting the greater saphenous vein for coronary artery bypass surgery. OBJECTIVE: To assess the integrity and function of the autologous, undistended, long saphenous vein harvested by a modified laryngoscope. METHODS: Morphology was examined by light and scanning electron microscopy. Endothelial function was assessed by vascular reactivity in an isolated organ bath. Veins, randomly taken and prepared traditionally, served as a control group. Contractile function was measured in response to potassium chloride. Endothelium-dependent relaxation was assessed by use of acetylcholine and calculated as percentage relaxation. RESULTS: There were no significant differences, in response to the constricting or dilating agent, in vein rings taken with the modified laryngoscope compared with the traditional 'open' technique (n = 10, p > 0.05 by ANOVA). Histologic examination by light and scanning electron microscopy showed no significant damage to the endothelial layer. CONCLUSION: Minimally invasive saphenous vein harvesting, using a modified laryngoscope yields morphologically and biologically intact veins.

Analysis of Variance↗