Biomedical subjects

Anton Moritz

Publications and source records attributed to Anton Moritz.

68 records · Page 4Linked to original sources

PubMed2002

Surgical treatment of tracheomalacia by bronchoscopic monitored aortopexy in infants and children.

BACKGROUND: Aortopexy has become an established surgical procedure for the treatment of severe tracheomalacia (TM) in infancy. However, postoperative outcome may be improved by intraoperative bronchoscopic control of the aortopexy. METHODS: Between 1992 and 2000, 16 infants and children (2 female, 14 male) with TM were treated by pexis of the aorta via a right (15 patients) or left (1 patient) anterior thoracotomy. Patients age ranged from 4 to 122 months (mean, 26 mon). Three infants had previous surgery for esophagus atresia and tracheoesophageal fistula. Another four patients were operated for gastroesophageal reflux. In all cases, the aortopexy was monitored intraoperatively by bronchoscopy. Respiratory function was verified for each patient by comparing pre- and postoperative tidal expiratory flow values (TEF 25% in ml/sec). RESULTS: Mean follow-up was 36 months (range, 2 to 60 mo). There was no intraoperative or postoperative mortality. 13 patients showed permanent relief of symptoms. Postoperative median TEF 25% increased significantly compared with preoperative values (81 ml/sec vs. 56 ml/sec; p = 0.016). In one patient repeat aortopexy was necessary. CONCLUSIONS: Aortopexy through a right anterior thoracotomy is an efficient and feasible method in the surgical treatment of TM in infancy and, therefore, can improve postoperative respiratory function. Intraoperative bronchoscopy is advantageous.

Aorta↗

PubMed2002

The Heartflo device for distal coronary anastomoses: clinical experiences in 60 patients.

BACKGROUND: The Heartflo anastomotic device automates the suturing process with simultaneous delivery of 10 standard polypropylene sutures through the graft and the coronary vessel wall to construct the anastomosis. We performed clinical testing in 60 patients undergoing coronary artery bypass grafting. METHODS: One automated distal coronary anastomosis was initially placed in each patient, the other anastomoses were created with standard running sutures. After a "flat foot"-shaped prototype was deployed in 30 patients (group I), the design of the foot was modified and deployment of the new device performed in the next 30 patients (group II). RESULTS: In group I, automated anastomoses were completed in 16 patients (53%) using 1.7 +/- 1 additional stitches. In 26 group II patients (86%), a hemostatic anastomosis using 1.2 +/- 1 additional stitches was achieved. Anastomoses were completed in 19.0 +/- 3 minutes in group I and in 15.6 +/- 2 minutes in group II. CONCLUSIONS: We have shown the feasability of coronary anastomoses using the Heartflo device. The modified version improved tissue capture, resulting in a higher rate of completed anastomoses. Because anastomotic time is still prolonged, an easier suture management is mandatory in the next developmental step.

Aged↗

PubMed2002

How safe is the port access technique in minimally invasive coronary artery bypass grafting?

BACKGROUND: This study compares conventional coronary artery bypass grafting (CABG) with port access CABG via a left anterior small thoracotomy in patients requiring surgical multivessel revascularization. Clinical, neuropsychological, and angiographic outcomes were studied, as well as parameters of myocardial and cerebral protection. Pathogenicity of cardiopulmonary bypass (CPB) was further evaluated by measuring parameters of peripheral limb ischemia and inflammatory whole-body response. METHODS: In a prospective randomized study, 40 patients who required multivessel CABG were assigned to either conventional CABG via complete median sternotomy (group A) or port access CABG via minithoracotomy (group B). Control angiograms were performed in group B only. In addition, patients underwent neuropsychological testing after the operation. CK, CK-MB, and Troponin T levels were documented. S-100B protein and neuron-specific enolase (NSE) served to quantify cerebral injury. The terminal complement complex (C5b-9) and myeloperoxidase concentrations were determined to analyze inflammatory whole-body response after CPB. RESULTS: There was no mortality. One patient suffered a retrograde aortic dissection immediately after onset of CPB, but had an uneventful postoperative course after surgical repair. Troponin T and CK-MB showed no difference between groups. CK and myoglobin were significantly higher in the minimally invasive cohort. Changes in complement activation (C5b-9) and myeloperoxidase during CPB markers of the whole-body inflammatory response were similar in both groups. S-100B concentrations in the port access group were significantly higher, whereas NSE levels were similar in both groups. Both groups did not display any significant difference in neuropsychological testing. CONCLUSIONS: Minimally invasive multivessel CABG via minithoracotomy using port access technology is feasible and safe. Though prolonged operating and CPB times with significantly higher S-100B concentrations were observed in group B, equivalent myocardial and cerebral protection and similar whole-body inflammatory response were documented.

Aged↗

PubMed2002

Initial in vivo results of the new Medtronic Advantage(TM) bileaflet valve in aortic position and comparison to the SJM.

The present study investigated the Medtronic Advantage (MA) bileaflet valve in an animal model and compared the results to the St. Jude Medical (SJM) valve. Systolic performance and coronary artery flow in different orientations were studied.A rotation device holding either a MA or SJM aortic valve size 23 mm was implanted into eight pigs. Transvalvular pressure gradients and ventricular dimensions were investigated with the valves in different orientations. Coronary artery flow was measured at normal and high cardiac output. Orientation significantly influenced the hemodynamic performance of both valves. The best results for both valves were obtained with one orifice proximal to the right cusp. Pressure gradients and ventricular dimensions of the MA corresponded to the SJM. Coronary artery flow was higher for the MA. The systolic performance of the new MA bileaflet valve was similar to the SJM. During diastole, the MA showed significantly higher LAD coronary flow.

Animals↗

PubMed2002

Vacuum-assisted suction drainage versus conventional treatment in the management of poststernotomy osteomyelitis.

OBJECTIVE: The purpose of our study was to compare vacuum-assisted suction drainage (VASD) to conventional wound management, in the treatment of poststernotomy osteomyelitis (SOM). METHODS: We included a total of 42 patients that developed poststernotomy osteomyelitis and required open wound management, between 1998 and 2000, in this study. Twenty of these patients were treated by VASD and the other 22 by conventional wound management. The patients were well comparable with regards to age, presenting postoperative day, infecting organism and risk factors for osteomyelitis. This was a retrospective study. RESULTS: The patients treated by VASD had a significantly reduced treatment duration (mean 17.2+/-5.8 vs. 22.9+/-10.8 days, P=0.009) and total hospital stay (mean 27.2+/-6.5 vs. 33.0+/-11.0 days, P=0.03). Perioperative mortality was similar, with one early death in each group. CONCLUSION: We conclude from our experience in the treatment of 42 patients with poststernotomy osteomyelitis that VASD shortened wound healing and hospital stay and thus proved to be an excellent alternative to conventional open management of these wounds.

Aged↗

PubMed2002

Robotically enhanced placement of left ventricular epicardial electrodes during implantation of a biventricular implantable cardioverter defibrillator system.

Biventricular pacing has gained increasing acceptance in advanced heart failure patients. One major limitation of this therapy is positioning the left ventricular stimulation lead via the coronary sinus. This report demonstrates the feasibility of totally endoscopic direct placement of an epicardial stimulation lead on the left ventricle using the daVinci surgical system.

Aged↗

PubMed2002

Effect of mechanical aortic valve orientation on coronary artery flow: comparison of tilting disc versus bileaflet prostheses in pigs.

OBJECTIVE: Orientation for optimal systolic performance of tilting disc and bileaflet aortic valves was defined in previous studies. The present study investigates the influence of valve orientation on coronary artery flow in an animal model. METHODS: A rotation device holding either a Medtronic Hall tilting disc (n = 4; Medtronic, Inc, Minneapolis, Minn), a St Jude Medical bileaflet (n = 4; St Jude Medical, Inc, St Paul, Minn), or a Medtronic Advantage bileaflet (n = 3) aortic valve was implanted. The device allowed rotation of the valve without reopening the aorta. Flow through the left anterior descending coronary artery was measured preoperatively and at normal versus high cardiac output after weaning from extracorporeal circulation. Measurements were performed at the best and worst hemodynamic position, as defined previously. RESULTS: Coronary flow rates were similar in all animals preoperatively (26 +/- 4.1 mL/min). After aortic valve replacement, left anterior descending flow increased significantly to 58.2 +/- 10.6 mL/min. Highest flow rates at normal cardiac output were found in the optimum orientation, especially for the Medtronic valves (Medtronic Hall, 64 +/- 8.7 mL/min; Medtronic Advantage, 64.6 +/- 11.6 mL/min; St Jude Medical, 48.3 +/- 10.3 mL/min), whereas the worst position demonstrated significantly lower left anterior descending flow, with no differences among valves (Medtronic Hall, 37.5 +/- 1.3 mL/min; St Jude Medical, 35.7 +/- 10.7 mL/min; Medtronic Advantage, 39.8 +/- 10 mL/min). Left anterior descending artery flow increased significantly with higher cardiac output. CONCLUSIONS: Coronary blood flow was significantly influenced by mechanical aortic valve implantation and the orientation of prostheses. For both valve designs, the previously defined optimum orientation with respect to pressure gradients and turbulence demonstrated the highest left anterior descending flow rates. Even in its optimum orientation, the St Jude Medical valve showed significantly lower coronary flow than the other valves.

Animals↗

PubMed2002

Techniques for the detection of coronary atherosclerosis: multi-detector row CT coronary angiography.

PURPOSE: To investigate the accuracy of different computed tomographic (CT) reformation techniques in assessing the coronary arteries. MATERIALS AND METHODS: Sixty-four patients undergoing both multi-detector row CT and invasive coronary angiography were consecutively included in a retrospective study. CT scans were obtained with collimation of 4 x 1 mm, pitch of 1.5, and rotation time of 500 msec. Retrospective electrocardiographic gating was used for image reconstruction, with 1.25-mm section thickness and 0.5-mm increment. The CT data set of each patient was evaluated by independent observers using transverse scanning, virtual endoscopic, and three-dimensional reformation and multiplanar reformation. RESULTS: Hemodynamically relevant stenoses (>50%) were detected with highest sensitivity at transverse scanning (58 of 79 [73.4%] stenoses), followed by virtual endoscopic (38 of 79 [48.1%] stenoses) and three-dimensional reformation (34 of 79 [43.0%] stenoses), and multiplanar reformation (37 of 79 [46.8%] stenoses). Atherosclerotic plaques were identified with comparable sensitivities at transverse scanning (143 of 218 plaques [65.6%]) and at three-dimensional (139 of 218 [63.8%] plaques) and virtual endoscopic reformation (136 of 218 [62.4%] plaques). Multiplanar reformation had distinctly poorer results (217 of 218 [58.3%] plaques). Combined interpretation with all four techniques increased sensitivity to 74.7% (59 of 79) for stenosis and 71.6% (156 of 218) for atherosclerosis. Calculated overall specificity was 91.4% or greater. Sufficient vascular evaluation was possible only in vessels larger than 1.6 mm in diameter. Thus, even in patients with heart rates below 60 bpm, only 80.0% of all coronary segments could be visualized, while at higher frequencies, visibility decreased to 66.2%. CONCLUSION: Although multi-detector row CT is a favorable alternative procedure in evaluating coronary arteries, its clinical value still is restricted to low heart rates and proximal coronary arterial segments.

Aged↗

PubMed2002

Coronary artery bypass grafting through complete sternotomy in conscious patients.

BACKGROUND: Complete sternotomy is the standard approach in cardiac surgery, and coronary artery bypass grafting (CABG) is the most common revascularization procedure to use this approach. A new technique has been developed that permits complete surgical revascularization with arterial grafts in awake patients. This technique, which we refer to as awake coronary artery bypass grafting, avoids general anesthesia, mechanical ventilation, and extracorporeal circulation, thereby creating the least invasive method for heart operations yet described. METHODS: A thoracic epidural catheter was placed at T2-T3 level one day before surgery. In 12 patients, single (n = 6), double (n = 5), or triple (n = 1) vessel coronary artery bypass grafting was performed without general anesthesia. In six patients, this procedure was performed after complete median sternotomy. RESULTS: Ten patients remained awake throughout the whole procedure. Two patients required secondary intubation due to incomplete analgesia in one case and pneumothorax in the other. Procedural time was 98.2 +/- 19.8 minutes. Intermediate care stay was 4.9 +/- 0.6 hours. There were no perioperative complications, and early angiographic results before discharge were excellent in all patients. CONCLUSIONS: The data presented show the feasibility and safety of complete surgical revascularization via median sternotomy using arterial grafts without general anesthesia. This approach shortens recovery time and increases patient comfort, suggesting that outpatient cardiac surgery may eventually be possible.

Aged↗

PubMed2002

Comparison of hemodynamic performance of Medtronic Hall 21 mm versus St. Jude Medical 23 mm prostheses in pigs.

BACKGROUND AND AIM OF THE STUDY: The ideal prosthesis for aortic valve replacement in the small annulus remains controversial, and has yet to be defined. In previous studies, the Medtronic Hall (MH) tilting disc valve showed superior hemodynamic performance in the hemodynamically optimum orientation compared to the St. Jude Medical (SJM) bileaflet valve, especially in smaller-sized valves. Using an animal model, the hemodynamics of 21 mm MH and 23 mm SJM valves, both of which have shown identical performance in previous clinical studies, were compared. METHODS: A rotation device holding either a MH or a SJM aortic valve was implanted into eight pigs. The device allowed rotation of the implanted valve without reopening the aorta. In different orientations (best and worst orientation hemodynamically as defined previously), transvalvular pressure gradients and ventricular dimensions were measured using transesophageal echocardiography at constant hemodynamic conditions. RESULTS: In the optimum hemodynamic orientation, pressure gradients of the MH valve (6.3+/-1.7 mmHg) corresponded to those obtained with the SJM valve (6.3+/-3.7 mmHg), whereas in the worst orientation the MH showed a tendency towards higher gradients (14.0+/-2.9 versus 10.3+/-4.0 mmHg) (p = not significant). A significant increase in left ventricular enddiastolic diameter was observed for both valve designs with rotation from the optimal into the worst orientation. CONCLUSION: In the optimum hemodynamic orientation, the 21 mm MH valve matched the hemodynamic performance of the 23 mm SJM valve. Thus, implantation of the MH valve might be an alternative to root enlargement and implantation of a larger SJM valve in patients with a small aortic annulus, though optimum orientation is required.

Animals↗

PubMed2002

Totally endoscopic bilateral internal thoracic artery bypass grafting in a young diabetic patient.

BACKGROUND: The introduction of robotics into cardiosurgical practice in 1998 has enabled totally endoscopic closed chest procedures. Totally endoscopic grafting of the LAD (TECAB) is no longer an experimental procedure. CASE REPORT: We report on a case with totally endoscopic bilateral internal thoracic artery bypass grafting to the left anterior descending and right coronary artery in a 36-year-old obese female diabetic patient using the daVinci surgical system. The patient, suffering from juvenile diabetes for 26 years, presented with stable angina (CCS class II). A coronary angiogram revealed 2-vessel disease with a long complex proximal lesion of the left anterior descending artery (LAD) (90%) and 80% stenosis of the proximal right coronary artery (RCA). Due to the condition of the proximal LAD (high risk PTCA with rather poor prognosis), the patient was referred for minimally invasive operative revascularisation of the LAD and the RCA. After informed consent was obtained the patient underwent totally endoscopic double internal thoracic artery bypass revascularisation on the arrested heart using computer-enhanced telemanipulation technology. RESULTS: The feasibility and safety of successful closed chest, totally endoscopic double coronary bypass grafting with two internal thoracic arteries is demonstrated in this case. Preservation of a stable chest cavity and reduced risk for wound healing complications in diabetics with an excellent cosmetic result are the obvious advantages of the techniques described.

Adult↗

PubMedDate not supplied

Relocalization of endothelial cell beta-catenin after coculture with activated neutrophils from patients undergoing cardiac surgery with cardiopulmonary bypass.

Cardiac surgery with cardiopulmonary bypass (CPB) is associated with neutrophil activation, inflammation, and consecutive edema. The impairment of endothelial junction molecules, and thus, hyperpermeability elicited by the interaction of activated neutrophils with endothelial cells may be important in this regard. Cocultures with human endothelial cells and neutrophils from 10 cardiac surgery patients with CPB were used to evaluate the role of neutrophils in modifications of the endothelial zonula adherens molecules VE-cadherin and beta-catenin. Laser scan microscopic analyses showed that neutrophils, which were isolated after the beginning of CPB, significantly impaired intracellular redistribution of endothelial beta-catenin with regard to membrane association (p <.0002) and staining pattern (p <.0001). VE-cadherin localization was not found to be significantly modified. Western blots with total cell extracts showed that amounts of beta-catenin did not vary significantly after co-culture with activated neutrophils. Activated neutrophils during cardiac surgery with CPB may induce endothelial dysfunction by impairing beta-catenin localization and thus contribute to endothelial hyperpermeability.

Antigens, CD↗

PubMedDate not supplied

Cardiac surgery with extracorporeal circulation: neutrophil transendothelial migration is mediated by beta1 integrin (CD29) in the presence of TNF-alpha.

Cardiac surgery with extracorporeal circulation is associated with neutrophil activation, inflammation, and edema. Endothelial hyperpermeability elicited by the interaction of activated neutrophils and/or cytokines with endothelial cells may be critical in this regard. However, the immune and cellular mechanisms involved are not fully understood. Cocultures with human endothelial cells and neutrophils from cardiac surgery patients were used to evaluate the role of beta1 integrin activity and the proinflammatory cytokine tumor necrosis factor (TNF)-alpha in neutrophil transendothelial migration and in impairment of the integrity of endothelial cell-to-cell contacts. Blocking of CD29 (heavy chain of beta1 integrins) totally prevented neutrophil adhesion and transendothelial migration. Pretreatment of neutrophils with either a CD29-stimulating monoclonal antibody or the addition of TNF-alpha (0.1-10 U/ml) to the coculture failed to induce transendothelial migration. However, coculture of endothelial cells with CD29-stimulated neutrophils in the presence of 0.1-10 U/ml TNF-alpha strongly induced neutrophil transmigration. CD29/TNF-alpha-mediated transmigration was associated with intracellular redistribution of endothelial beta-catenin. We further showed that CD29/TNF-alpha-mediated effects involved PI3K and tyrosine kinase-dependent signaling via MAPK but were independent of nuclear transcription factor (NF)-kappaB activity. Inhibition of CD29/TNF-alpha might be a therapeutic option to limit endothelial dysfunction following cardiac surgery with extracorporeal circulation.

Cell Movement↗

PubMedDate not supplied

First efficacy and safety results with the antibody containing leukocyte inhibition module in cardiac surgery patients with neutrophil hyperactivity.

Systemic administration of immune modulating antibodies may play an important role in reducing neutrophil hyperactivity, for example, in patients undergoing cardiac surgery with extracorporeal circulation or in trauma patients. However, this strategy has extremely high costs and is often associated with severe adverse effects. We developed the Leukocyte-Inhibition-Module (LIM), an extracorporeal circulation (ECC) device housing a polyurethane matrix with covalently bound Fas (CD95; APO-1) stimulating antibodies to rapidly prevent neutrophil hyperactivation. A feasibility study with 14 patients undergoing cardiac surgery with the use of immunogenic ECC without (n = 5) and with (n = 9) LIM (venous line) was performed. Our data show that the usually observed ECC associated perioperative increase in neutrophils (control) was prevented by LIM (p = 0.023). Moreover, the increase of the proinflammatory markers tumor necrosis factor (TNF)-alpha and polymorphonuclear elastase was limited by LIM (p = 0.038 and p = 0.002). In both groups, no significant changes in liver enzymes or in clotting were detected after surgery, and up to 12 months follow up, no unusual complications were reported. This study shows for the first time to our knowledge the feasibility, efficacy, and safety of a new cost effective, immune management strategy in patients with aberrant immune activation by exposing the blood stream to immobilized agonistic anti-Fas antibodies.

Antibodies↗