Biomedical subjects

A Moritz

Publications and source records attributed to A Moritz.

At least 37 records · Page 2Linked to original sources

PubMed2004

Elimination of microbubbles from the extracorporeal circuit: dynamic bubble trap versus arterial filter.

BACKGROUND: Open heart surgery is associated with important risk of cerebral and peripheral organ dysfunction, attributed in part to microbubbles generated in or not eliminated from the ECC. For elimination of microbubbles, a dynamic bubble trap (DBT) was developed for the arterial line of ECCs. METHODS: Bubble eliminating properties of an arterial filter were evaluated in four CABG patients and compared to the performance of the DBT in four patients. One patient received both devices. RESULTS: Elimination of bubbles between 40-120 microm was significantly higher with the DBT (88% vs. 57% with arterial filter, p=0.034). Reduction of bubbles below 40 microm was equivalent in both groups. The combination of both devices was most effective (94% for bubbles >40 microm). CONCLUSION: Arterial filter and DBT are equally effective in elimination of smaller gas bubbles. However, bigger bubbles possibly causing cerebral and peripheral organ damage are eliminated to a greater degree by the DBT.

Coronary Artery Bypass↗

PubMed2004

Inhibition of neutrophil activity in cardiac surgery with cardiopulmonary bypass: a novel strategy with the leukocyte inhibition module.

Recently, we showed that the arterial in-line application of the leukocyte inhibition module (LIM) within the heart-lung machine limits overshooting leukocyte activity and cardiac tissue damage. Moreover, significantly better cardiac function was found in an experimental animal model when LIM was used. In the meantime, the first promising clinical data exist. LIM has to be regarded as an essential tool in extracorporeal circulation, in the future, to improve postoperative clinical outcome and to reduce costs. This review summarizes the biological background of LIM and the current experience obtained in experimental models and clinical studies.

Animals↗

PubMed2003

Perioperative elastase activity in cardiac surgery and its role in endothelial leakage.

OBJECTIVE AND DESIGN: The functional activity and pathophysiological effects of polymorphonuclear elastase (PMNE) in cardiac surgery patients are unknown. This in vitro study was done to evaluate whether PMNE activity in patient blood samples may be correlated with decreased endothelial wall integrity. METHODS AND SUBJECTS: PMNE was serially analyzed by PMNE activity in plasma samples from 40 high risk cardiac surgery patients. Endothelial cell cultures were used to study the influence of patient serum on the intercellular integrity. RESULTS: Ex vivo, samples with high PMNE activity (>1.0 mg/ ml), found in 14 patients (35%), neither induced hyperpermeability in cultured endothelial cells nor resulted in intracellular redistribution of the junction molecules cadherin-5 or beta-catenin. However, pretreatment of endothelial cells with these samples but not with low activity (<0.5 mg/ml) samples augmented neutrophil transendothelial migration (>20-fold) in conjunction with formation of intercellular gaps and irregular membrane-associated beta-catenin staining. Neutrophil transmigration was inhibited by blocking neutrophil beta1 integrin but not by the proteinase inhibitor methoxysuccinyl-Ala-Ala-Pro-Ala. CONCLUSIONS: Augmented PMNE activity in cardiac surgery patients does not directly induce endothelial leakage but may indirectly promote neutrophil extravasation and thus perioperative endothelial hyperpermeability.

Blood-Air Barrier↗

PubMed2003

[Thrombosed pseudoaneurysm after aortic root replacement-sternal penetration with skin perforation as a late complication].

Aortic pseudoaneurysm is a potential complication after aortic root replacement. Occurrence has been reported up to 7% of cases, and is due to dehiscence of the anastomotic suture line. We report a case of sternum erosion and skin perforation 8 years after composite graft replacement as a consequence of a ventricular-aortic dehiscence that led to a giant spontaneously healed thrombotic pseudoaneurysm. Our patient developed a secondary sternal fistula without pain or other clinical symptoms. Chest Xray examination revealed an abnormal mediastinal mass. The tumor was recognized on a computed tomography scan; the mass was identified as spontaneously healed thrombosed pseudoaneurysma with sternal penetration. Repair could be performed on the beating heart. Postoperative right heart failure with signs of myocardial infarction was attributed to the chronically occluded right coronary artery.

Adult↗

PubMed2003

Operative techniques in awake coronary artery bypass grafting.

BACKGROUND: Off-pump coronary artery bypass grafting was implemented to reduce trauma of surgical coronary revascularization by avoiding extracorporeal circulation. High thoracic epidural anesthesia further reduces intraoperative stress and postoperative pain. In addition, this technique even allows awake coronary artery bypass grafting, avoiding the drawbacks of mechanical ventilation and general anesthesia in high-risk patients. METHODS: Thirty-four patients underwent awake coronary artery bypass grafting with left internal thoracic artery to left anterior descending coronary artery by partial lower ministernotomy (n = 20), H-graft technique (n = 2), or rib cage-lifting technique (n = 2). In 9 cases we performed double bypass grafting, and in 1 case we performed triple-vessel coronary artery revascularization through complete median sternotomy. In addition to clinical outcomes, visual analog scale pain scores were recorded on days 1, 2, and 3 after surgery. RESULTS: Thirty-one patients remained awake throughout the whole procedure. Three patients required secondary intubation because of incomplete analgesia (n = 1) or pneumothorax (n = 2). Procedure time was 90 +/- 31 minutes, and recovery room stay was 4.2 +/- 0.6 hours. There were no in-hospital deaths or serious postoperative complications. In 1 case a graft occlusion was documented on predischarge angiography. Early postoperative pain was low (visual analog scale score of 30 +/- 6). CONCLUSION: These data demonstrate the feasibility and safety of various surgical coronary revascularization techniques without general anesthesia. Continuation of thoracic epidural analgesia provides good pain control and fast mobilization postoperatively. Surprisingly, the awake coronary artery bypass grafting procedure was well accepted by the patients.

Aged↗

PubMed2003

Do surface modifying additives (SMA) influence blood loss and thrombogenicity in conventional cardiopulmonary bypass for coronary artery bypass grafting?

Cardiopulmonary bypass (CPB) leads to activation of the coagulation and fibrinolytic cascades, partially associated with foreign surface contact. Hemorrhage and the need for blood products is associated with rising cost and increased risk of infection. Treatment with surface modifying additives (SMA) has been shown to reduce thrombogenicity and improve biocompatibility. 76 elective CABG-patients were randomly assigned to surface modifying additives (group I, n=39) or untreated circuits that were otherwise identical (group II, n=37). Measurements of coagulation activity and fibrinolysis, platelet count and function were made. The postoperative blood loss and blood product replacement was also assessed. Thrombin formation measured by prothrombin fragments 1+2 (5.7+/-0.4 nmol/l vs. 5.6+/-0.4 nmol/l), fibrinolytic activity measured by plasmin-antiplasmin complex (1752.6+/-216.8 microg/l vs.1180.0+/-74.8 microg/l) and the postoperative platelet count and function did not differ significantly between the two groups. Blood loss and transfusion requirements were slightly lower in the SMA group. The treatment of extracorporeal surfaces with surface modifying additives does not appear to reduce coagulation disorders and bleeding after conventional CPB.

Aged↗

PubMed2003

Performance of stentless versus stented aortic valve bioprostheses in the elderly patient: a prospective randomized trial.

OBJECTIVES: Although stentless aortic bioprostheses are believed to offer improved outcomes, benefits remain unsubstantiated. The aim of our study was to compare stentless with stented bioprostheses, with regard to postoperative changes in left ventricular mass and hemodynamic performance, in the elderly patient. METHODS: Forty patients with aortic stenoses, over the age of 75 years, were randomized to receive either the stented Perimount (n=20) or the stentless Prima Plus (n=20) bioprosthesis. Left ventricular mass regression, effective orifice area, ejection fraction and mean gradients were evaluated at discharge, 6 months and 1 year after surgery. RESULTS: Overall a significant decrease in left ventricular mass was found 1 year postoperatively. However, there was no significant difference in the rate of left ventricular mass regression between the groups. Furthermore, 1 year postoperatively, the hemodynamic performance of the valves and the change in the ejection fraction did not differ between the groups. CONCLUSIONS: Our study shows that in a randomized cohort of elderly patients with aortic stenosis, we were not able to detect significant differences, with regard to hemodynamic performance and regression of left ventricular mass, between the stentless and stented valve groups. To our surprise, previously reported findings of non-randomized trials that showed faster and more complete regression of left ventricular mass and hemodynamic benefits of stentless valves were not reproducible.

Aged↗

PubMed2003

Thoracic epidural anesthesia does not influence the incidence of postoperative atrial fibrillation after beating heart surgery.

BACKGROUND: At least 20 - 30 % of patients undergoing coronary artery bypass graft surgery (CABG) or beating-heart surgery develop postoperative atrial fibrillation (AF). We evaluated the effect of thoracic epidural anesthesia (TEA) on the occurrence of postoperative AF in patients submitted to CABG without cardiopulmonary bypass (OPCABG). METHODS: We performed a retrospective analysis of 125 patients undergoing myocardial revascularization. Early postoperative incidence of AF was compared between three groups of patients - 50 after conventional CABG, 45 after OPCABG, and 30 after OPCABG combined with TEA intraoperatively and postoperatively. Clinical profile of the patients, including factors with a potential influence on postoperative AF was matched for groups. RESULTS: Postoperative AF occurred in 13.3 % of the TEA-treated patients, in 17.7 % of the patients in the OPCABG group, and in 26 % of the patients in the CABG group. This difference did not carry any statistical significance. Risk factors and incidence of postoperative complications were comparable in all groups. CONCLUSION: TEA has no effect on the incidence of postoperative AF in patients undergoing beating-heart surgery.

Aged↗

PubMed2003

Five-year follow-up after long plaque-bridging coronary arteriotomy for diffuse coronary artery disease.

UNLABELLED: Long arteriotomy bridging a stenotic plaque or segment may improve runoff in diffuse coronary artery disease. However, patency might be impaired due to vascular wall pathology. OBJECTIVE: To determine the patency rates of plaque-bridging arteriotomy compared to conventional coronary artery bypass grafting. METHODS: Between May 1995 and December 1998, 104 patients with a mean age of 65 +/- 7 years received a long arteriotomy extending over a heavily plaqued area in an effort to treat their diffuse coronary artery disease. The length of the arteriotomy ranged from 14 mm to 40 mm. We retrospectively analyzed the intra-individual bypass graft patency rates by multidetector-computed tomography or coronary angiography. RESULTS: The mean follow-up was 5 years. There were 5 (4.8 %) early and 10 (9.6 %) late deaths, three non-cardiovascular. Graft patency for internal thoracic artery (ITA) to left anterior descending artery (LAD) (plaque-bridging) was 94.8 %, for saphenous vein graft (SVG) to circumflex artery (CX) (plaque-bridging) 67 %, and SVG to right coronary artery (RCA) (plaque-bridging) 79.5 %. Graft patency for ITA to LAD (conventional) was 94.9 %, for SVG to CX (conventional) 72.4 %, and SVG to RCA (conventional) 75 %. Freedom from angina was 82.8 % (n = 58/70), freedom from myocardial infarction was 95.7 % (n = 67/70), freedom from reintervention was 91.4 % (n = 64/70) and freedom from reoperation was 100 % (n = 70/70). CONCLUSION: Diffuse coronary artery disease can be treated by extending the arteriotomy over the plaques, with graft patency rates comparable to bypass grafts onto less diseased segments.

Aged↗

PubMed2003

Cardiopulmonary bypass impairs left ventricular function determined by conductance catheter measurement.

OBJECTIVE: Postoperative cardiac depression is attributed to ischemia and the effects of cardiopulmonary bypass (CPB). To evaluate the effect of CPB alone on postoperative left ventricular (LV) dysfunction, we used a conductance catheter to determine the LV performance by pressure-volume relation before and after CPB. METHODS: Twenty-two 3-week-old piglets underwent sternotomy and normothermic CPB for one hour. A conductance catheter was placed in the LV cavity. End-systolic pressure-volume relationships (ESPVR), left ventricular end-diastolic pressure (LVEDP) and systemic vascular resistance (SVR) were measured under steady-state conditions before and 15 min after weaning from CPB in group A (n = 11). Group B included 11 piglets without CPB and served as control. RESULTS: There was no difference between groups before initiating CPB. As an indication of depressed LV function, the ESPVR slope (mmHg/ml) was significantly lower in group A after weaning from CPB than in group B (1.69 +/- 0.5 vs. 1.86 +/- 0.55; p = 0.008). In group A, peak dP/dt (max index) (mmHg/s/m (2)) decreased markedly (1596 +/- 339 vs. 2045 +/- 206; p = 0.03), while LVEDP (mmHg) was significantly increased (11.7 +/- 2.6 vs. 5.4 +/- 0.9; p < 0.0001). In addition, SVR (index) (dyn x s x cm (-5)/m (2)) in group A was significantly lower (1407 +/- 176 vs. 1677 +/- 313; p < 0.0001) than in group B. CONCLUSION: Using the very sensitive conductance catheter technique in a pig model, we could show that CPB leads to a significant depression of LV contractility and elastance even without ischemic arrest.

Animals↗

PubMed2002

Leukocyte filtration fails to limit functional neutrophil activity during cardiac surgery.

OBJECTIVE AND DESIGN: The beneficial effects of leukocyte filtration on the outcome of cardiac surgery with cardiopulmonary bypass (CPB) is probably due to the limitation of pathogenesis mediated by over-stimulated neutrophils. However, the influence of leukocyte filtration on the functional neutrophil activity has not been studied in detail. Therefore, by using different filtration timing strategies we determined neutrophil effector functions before and after the filter passage as well as blood surrogate markers for neutrophil activation. METHODS: We randomly assigned 80 cardiac surgery patients to four groups (n = 20 each) without (1) and with three different filtration timing strategies (II-IV). As functional end points neutrophil phagocytic activity and oxidative burst upon ex vivo stimulation with E.coli were analyzed from blood of 31 patients whereas polymorphonuclear elastase (PMNE), myeloperoxidase, and malondialdehyde (MDA), a marker for lipid peroxidation was determined in plasma samples from 80 patients. Blood was harvested immediately before and behind the filter (Pall LG6) at different times during CPB. RESULTS: We found that none of the filtration strategies either reduced the number of neutrophils capable of eliciting phagocytic activity and oxidative burst or the activity per cell. In contrast, PMNE and MPO levels in peripheral venous blood were found to be significantly increased in groups II-IV compared with group I throughout the entire filtration period in all patients. MDA was not enhanced in the filter groups. CONCLUSIONS: Our results show that the leukocyte depletion filter in the arterial line of the heart-lung machine failed to limit neutrophil stimulation but rather augmented PMNE plasma levels. We speculate that augmented PMNE and MPO levels mainly stem from neutrophils that are captured within the mesh of the leukocyte filter.

Aged↗

PubMed2002

[Total arterial bypass operations with complete sternotomy in the awake patient].

BACKGROUND: In minimally invasive coronary artery bypass surgery beating heart procedures and operations via limited incisions became more popular and are routinely performed in many centers. An additional approach to minimize general trauma is avoidance of general anesthesia endotracheal intubation. PATIENTS AND METHODS: Between March and June 2001, 14 spontaneously breathing patients underwent coronary artery bypass grafting on the beating heart without general anesthesia. Intra- and postoperative analgesia management was performed using continuous epidural infusion of local anesthetics at level Th2-Th3. Single (n = 8) as well as double (n = 5) and triple (n = 1) bypass grafting was performed with the off pump technique. Surgical access to the chest cavity was created via partial (n = 8) or complete sternotomy (n = 6). RESULTS: Twelve patients remained awake throughout the procedure; 2 patients required secondary intubation due to incomplete sensory block and pneumothorax. Operating time was 94 +/- 18 minutes. Intermediate care monitoring time amounted to 4.8 +/- 0.6 hours. No surgery-related complications or myocardial infarction occurred. Postoperative angiography reviewed good graft function in all patients. CONCLUSION: Our preliminary experience shows that complete surgical revascularization is safe and feasible without endotracheal intubation and general anesthesia. Thus, invasiveness in cardiac surgery is further reduced with less need for intensive care unit monitoring enabling faster mobilization and recovery.

Aged↗

PubMed2002

[Successful reoperation of a ruptured aortic arch aneurysm in Takayasu arteritis].

Successful reoperation of a ruptured aortic arch aneurysm in a patient with Takayasu's disease. Takayasu's disease is an inflammatory arteriopathy that often progresses to stenosis or aneurysms of the large arteries of the aortic arch. In this connection aneurysms of the ascending aorta are rare. We report the case of a 33 years old female with a ruptured aneurysm of the ascending aorta complicated by a former operation of a truncobicarotidal bypass and severe sclerosis. After ascending aorta and aortic arch replacement was performed in deep hypothermia circulatory arrest we could discharge the patient in good condition on the 11. postoperative day.

Adult↗

PubMed2002

Sutured coronary artery grafting utilizing the Heartflo anastomosis device--first clinical experiences.

BACKGROUND: The Heartflo device was developed to facilitate consistency in distal coronary anastomosis quality. The device automates the suturing process during the anastomosis procedure via simultaneous delivery of ten standard 7-0 polypropylene sutures through the graft and the coronary vessel wall. METHODS: In 30 elective coronary artery bypass patients, one distal anastomosis was intentionally performed with the anastomosis device. Device success was stated if a patent anastomosis with a minimal flow of 50 ml/min resulted, additional stitches were counted if bleeding occurred. RESULTS: 4 cases of device failure occurred in the first 5 patients. The subsequent patients were operated without any mechanical problems. In 16 patients (53 %), a patent anastomosis with a mean flow of 75 +/- 6 ml/min using 1.7 +/- 0.3 additional stitches was achieved. Anastomoses were completed in 19.0 +/- 0.7 min; postoperative course was uneventful in all patients. CONCLUSIONS: We have shown that coronary anastomoses are feasible using the Heartflo device, representing a promising step on the way to automated coronary anastomoses. Its application is still limited by the size and tissue quality of the target vessel and difficult suture management during the anastomosis procedure.

Aged↗

PubMed2002

Five-year experience with valve sparing surgery for aortic root aneurysms.

BACKGROUND: The aim of this study was to analyze the mid-term results of aortic root reconstruction. METHODS: Between September 1995 and March 2001, 32 patients (25 males, 7 females, median age 58 +/- 21 years) underwent aortic root reconstruction as described by T. David. Indications for operation were aortic insufficiency with ascending aortic aneurysm in 27 patients, and acute aortic dissection (Stanford type A) in 5 patients. In all patients the native valve was preserved and suspended inside a tubular prosthesis with reimplantation of the coronary arteries. In 10 patients the classic reconstruction technique was modified by shaping a "Neosinus." RESULTS: There was one perioperative death due to myocardial infarction. Two patients suffered a stroke. 26 patients were followed up 12 months postoperatively. 22 out of 26 patients were in NYHA functional class I, 2 patients in class II and the remaining 2 in class III. Three patients died in the postoperative period. Six patients had trivial AR, 4 mild and 1 moderate regurgitation. There were no thromboembolic events during follow up. The mean transvalvular gradient was 3.5 +/- 2.2 mmHg. Compared to a normal cohort of patients (n = 20), resuspended aortic valves opened (26.4 +/- 5.8 vs. 61.3 +/- 22.1 cm/sec, p < 0.0001) and closed (22.8+/- 6.9 vs. 57.9 +/- 22.3) at a higher speeds and also showed shorter opening (0.053 +/- 0.12 vs. 0.023 +/- 0.09 sec, p < 0.0001) and closing times (0.051 +/- 0.07 vs. 0.23 +/- 0.07 cm/sec) of the aortic leaflets. CONCLUSIONS: Aortic valve reimplantation is a reliable technique able to reduce long term complications when compared to conventional composite graft replacement of the aortic root. Altered leaflet opening and closing dynamics do not impair midterm durability.

Adolescent↗

PubMed2002

Computer-enhanced telemanipulation enables a variety of totally endoscopic cardiac procedures.

BACKGROUND: Since its introduction in the field of cardiac surgery in 1997, computer-enhanced telemanipulation has been used in a number of different specialized areas. In cardiac surgery, various procedures have been successfully completed in totally endoscopic fashion ever since. Between June 1999 and January 2002, 75 closed-chest cardiac procedures have been performed at our institution using the da Vinci telemanipulation system. PATIENTS AND METHODS: In 42 patients, a single-vessel totally endoscopic coronary artery bypass was performed on the arrested heart (left internal thoracic artery (LITA) to left anterior descending artery (LAD), n = 36; right internal thoracic artery (RITA) to right coronary artery (RCA), n = 6). 12 patients had different types of multivessel revascularization using both internal thoracic arteries. 8 patients underwent LITA-to-LAD grafting on the beating heart. 10 patients underwent closure of an atrial septal defect (9 direct, 1 patch). 3 patients received an epicardial left ventricular pacemaker lead, 2 of which were reoperations. RESULTS: Overall conversion rate to any kind of incision was 25 %. The last 26 LITA to LAD patients on the arrested heart had a conversion rate of 4 %. There were no mortalities, 3 patients required reexploration via a median sternotomy, and one patient suffered a hypoxemic brain damage. The first 22 TECAB patients demonstrated excellent graft patency in angiographic control upon discharge. None of the atrial septal defect (ASD) closures showed any residual shunt on the intraoperative transesophageal echocardiogram (TEE). Patients with end-stage heart failure had successful biventricular stimulation. CONCLUSION: Our current experience confirms the feasibility of various totally endoscopic cardiac procedures with good clinical outcomes. After a steep learning curve, the conversion rate could be lowered to an acceptable figure. Some of these procedures at our institution became a reasonable treatment alternative in selected patients.

Coronary Artery Bypass↗

PubMed2002

Left ventricular thrombus capture by an intra-aortic filter device.

Left ventricular aneurysmectomy in patients with mobile, protruding thrombi is associated with increased risk of neurological complications due to loss during left ventricular luxation or embolisation of residual thrombotic material after incomplete removal. Embolisation can be prevented by application of an intra-aortic filter device. Here, we report on a case involving an important left ventricular thrombus captured in a patient referred for coronary artery bypass grafting, left ventricular aneurysmectomy, and thrombectomy.

Adult↗

PubMed2002

Totally endoscopic coronary artery bypass grafting on cardiopulmonary bypass with robotically enhanced telemanipulation: report of forty-five cases.

BACKGROUND: Robotically enhanced telemanipulation is a new powerful tool for minimally invasive procedures that allows totally endoscopic cardiac surgery. Between June 1999 and February 2001, 45 robotically enhanced totally endoscopic coronary artery bypass grafting procedures on the arrested heart were performed at our institution with the use of the da Vinci telemanipulation system (Intuitive Surgical, Inc, Mountain View, Calif). METHODS: In 37 patients a single-vessel totally endoscopic coronary bypass operation was performed. Eight patients had different types of multivessel revascularization with both internal thoracic arteries. The initial conversion rate was 22% and dropped to 5% in the last 20 patients. Two patients required reexploration via median sternotomy. The first 22 patients had excellent graft patency on discharge. The procedural time for single-vessel totally endoscopic bypass was 4.2 +/- 0.4 hours, bypass time was 136 +/- 11 minutes, and aortic crossclamp time amounted to 61 +/- 5 minutes. CONCLUSION: The present data show the feasibility of closed chest single- and double-vessel revascularization, with good clinical results. However, procedural time is prolonged and the complex endoscopic and endoaortic occlusion techniques, as well as the extensive anesthesiologic monitoring, are demanding. The need for conversion to an open procedure diminished after a relatively short learning curve. All postulated benefits of totally endoscopic surgery other than excellent cosmesis must be evaluated in larger cohorts.

Aged↗