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BACKGROUND AND OBJECTIVE Implantation of a VDD pacemaker (ventricular pacing; dual sensing [atrial and ventricular]; dual response [triggered + inhibited]) together with a single VDD electrode catheter restores synchronous AV ventricular stimulation in patients with higher-grade AV block and intact sinus function. If higher-frequency stimulation occurs it may be a sign of pacemaker malfunction or of inadequate pacemaker programming. This study was undertaken to determine, at first follow-up examination, in how many patients with a VDD pacemaker VVI stimulation occurred more than 5% of the time; how such patients differed from those with 5% or fewer VVI stimulations; and whether a changed program reduced the proportion of VVI stimulations. PATIENTS AND METHODS 67 consecutive patients were tested 1 to 3 months after implantation of the Unity VDD pacemaker (Sulzer Intermedics). The frequency of VVI stimulations was determined via a diagnostic pacemaker memory store. After intermediate analysis, programming was optimized and the patients then re-tested 12 months after the initial implantation. RESULTS At the first follow-up examination 54 patients had VVI stimulations of 5% of the time (19.8 +/- 10.7%). The two groups differed significantly from one another in their lower intervention frequency ( 5% VVI stimulations: 58 +/- 5/min). In particular, the pacemakers in patients with > 5% VVI stimulations had been significantly more often programmed to values of > 50/min. As a result, the pacemakers of these patients were reprogrammed to a lower frequency. A year after implantation there was no longer any difference in the lower intervention frequency, 44 +/- 4/min, between patients with initially > 5% VVI stimulations and those with initially 95%. INTERPRETATION At first follow-up, patients with > 5% VVI stimulations differed from those with 95% by reducing the lower intervention frequency to < or = 50/min.

In einer bizentrischen Studie zur postmortalen In-situ-Messung von Herzschrittmachern und deren Elektroden sollten mogliche Dysfunktionen detektiert und analysiert werden. Die Stichprobe rekrutierte sich uberwiegend aus Schrittmachertragern, die im Rahmen der zweiten auseren Leichenschau vor Kremierung begutachtet wurden. Das entwickelte Messverfahren vor Ort am Leichnam beinhaltete: 1. Ableitung eines Schrittmachersignals von der Korperoberflache, 2. Synchronisationstest mit einem Testschrittmacher, 3. Elektrodenfunktionsprufung. Im Anschluss an die Messung wurden die Schrittmacher explantiert und im Labor einer weiter gehenden Untersuchung unterzogen. Bei in situ erkannten Dysfunktionen wurde die Todesursache nach Moglichkeit zusatzlich autoptisch geklart. Mit Hilfe dieses Messverfahrens sollten forensisch relevante Fragen beantwortet werden, die sich aus der genannten Problematik ergeben. Ergebnisse einer Zwischenauswertung an 415 Schrittmachern belegen eine Gesamtauffalligkeitsrate von 23,2%, dabei lag in 3,9% der Falle eine lebensbedrohliche Dysfunktion vor. Hieraus ableitbare juristische Fragestellungen ergeben sich sowohl unter straf-, als auch zivil- und versicherungsrechtlichen Gesichtspunkten.

Nach penetrierenden Herzverletzungen wird die Prognose im Wesentlichen von einer zielgerichteten Erstversorgung und einer schnellen Einlieferung in die nachstgelegene Akutklinik bestimmt.Dort muss der Verletzte nach Sicherung der Diagnose ohne weiteren Zeitverzug einer operativen Therapie zugeleitet werden.Anhand eines Falles und der aktuellen Literatur wird die Bedeutung eines straffen Notfallmanagements dargestellt.Dem Einsatz der extrakorporalen Zirkulation (HLM) kommt in der Akutversorgung eine eher untergeordnete Bedeutung zu.

Background From March 2007 to July 2010, we performed 14 AB0-incompatible (AB0i) living kidney transplantations using donor blood group-specific immunoadsorption (IA), anti-CD20 monoclonal antibody, and intravenous immunoglobulin (IVIG) pretreatment. Methods To analyze the effect of a presumed anti-donor blood group–specific antibody transfer by IVIG administration (0.5 g/kg; 5.4 ± 0.9 days pretransplant), we assessed AB0i antibody titers in different IVIG preparations and evaluated their impact on patient AB0i antibody titers. Results AB0i antibody IgG titers before treatment ranged from 8 to 1024. We performed 6.9 ± 1.1 IA procedures pretransplant to reach AB0i antibody titers ≤4, which enabled successful transplantation in all pretreated patients. Their mean serum creatinine at discharge was 1.5 ± 0.1 mg/dL. IVIG preparations differed profoundly in their AB0i antibody titers: The lowest titers were observed in Sandoglobulin preparations (1–8) compared with Intratect (2–128), Octagam (4–32) and Gamunex (2–512). Usually, administration of the IVIG preparation containing the lowest isoagglutinin titer resulted in low AB0i antibody titer increments in patient sera: Sandoglobulin, 2 titer steps ( n = 2), 1 titer step ( n = 1), and 0 titer steps ( n = 5). In contrast, Octagam showed 0 titer steps ( n = 2) and Intratect, 0 titer steps ( n = 3). However, after Gamunex administration, the AB0i antibody titer of 8 and the AB0i antibody titer rose 3 titer steps (16 to 128; n = 1), which could not be explained by passive transfer of isoagglutinin alone. Conclusion Our data showed that the choice of IVIG preparation with the lowest AB0i antibody levels is a time- and cost-sparing step in the pretreatment of AB0i living donor kidney recipients. Posttransplant, a high isoagglutinin content within the IVIG preparation has the potential to induce antibody-mediated rejection.

Atrial synchronous ventricular pacing seems to be the best pacing mode for patients with advanced AV block and impaired LV function. The long-term follow-up of single lead VDD pacing was studied in 33 patients with impaired LV function and compared to 42 patients with normal LV function. All patients received the same VDD lead and VDDR pacemaker. The lead model with 13-cm AV spacing between the atrial and ventricular electrode was implanted in 89% of the patients. Follow-ups were 1, 3, 6, and 12 months after implantation. The percentage of atrial sensing and the P wave amplitude were determined at each follow-up. Minimal P wave amplitude at implantation was 2.0 +/- 1.4 mV in patients with impaired and 1.7 +/- 0.9 mV with normal LV function (not significant). At the 12-month follow-up, 33 patients with normal and 23 patients with depressed LV function remained paced in the VDD mode. The remaining patients died in five (impaired LV function) and seven cases (normal LV function) or their pacemakers were programmed to the VVI/VVIR pacing mode in four (impaired LV function) and three cases (normal LV function). P wave amplitude did not differ in the two groups (e.g., at month 12: impaired: 1.17 +/- 0.42 mV; normal: 1.09 +/- 0.49 mV). The atrial sensitivity was programmed in most patients to sensitive settings with no differences between the two groups (e.g., at month 12: impaired: 0.13 +/- 0.06 mV; normal: 0.13 +/- 0.05 mV). The diagnostic counters indicated nearly permanent atrial sensing (e.g., at month 12: impaired: 99.3 +/- 2.2%; normal: 99.0 +/- 1.0 mV). In conclusions, single lead VDD pacing restored AV synchronous ventricular pacing in patients with normal and with impaired LV function indicating that it could be an alternative to DDD pacemakers, but not to dual-chamber pacing.

Da sich die Stimulationsimpedanz invers zum Stimulationsstrom verhalt, senken hohe Impedanzwerte bei gleichbleibenden Stimulationsimpulsen zusatzlich den Stimulationsstrom. Inwieweit der intraoperativ gemessene Impedanzwert der Ventrikelstimulation reprasentativ fur den Langzeitverlauf ist, wurde bei 87 Patienten untersucht, die die VDD-Einzelelektrode UniPass 425 und den Schrittmacher Unity (Sulzer Intermedics) erhalten hatten. Es wurden die Impedanzanderungen zwischen Implantations- und 6-Monats-Zeitpunkt ermittelt. Als gleiche Impedanzwerte wurde definiert, wenn beide Meswerte ≤± 100 Ω voneinander abwichen. Kleinere bzw. grosere Impedanzwerte lagen 6 Monate nach Implantation vor, wenn sie sich > ± 100 Ω vom Implantationswert unterschieden. Intraoperativ betrug die Impedanz 535 ± 98 Ω (Spannweite: 333–811 Ω) und war nach 6 Monaten signifikant auf 604 ± 160 Ω (Spannweite: 361–1150 Ω) angestiegen. Der Unterschied zwischen den beiden Impedanzwerten betrug 69 ± 162 Ω (Spannweite: -336 bis +560 Ω). Gleiche Impedanzwerte lagen bei 43 (Implantation: 527 ± 75 Ω, 6 Monate: 531 ± 87 Ω), kleinere bei 11 (Implantation: 660 ± 83 Ω, 6 Monate: 494 ± 73 Ω) und grosere bei 33 Patienten (Implantation: 503 ± 99 Ω, 6 Monate: 735 ± 168 Ω) vor. Im Vergleich zu den Patienten mit gleichbleibenden Impedanzwerten hatten Patienten mit niedrigeren Impedanzen bei Implantation signifikant hohere Ausgangswerte. Schlusfolgerungen: Die Stimulanzimpedanz nimmt im Laufe von 6 Monaten nach Implantation signifikant zu. Bei 51% der Patienten kommt es zu deutlichen Veranderungen der Stimulationsimpedanz. Diese lassen sich in der Tendenz, aber nicht im Einzelfall voraussagen.

OBJECTIVE By means of transcranial Doppler sonography (TCD), microembolic signals (MES) representing embolic events can be registered during cardiac surgery and extracorporeal circulation in a considerable number of patients. We conducted the present study to determine the neuro-psychiatric consequences of MES. METHODS 25 patients scheduled for elective aorto-coronary bypass grafting (ACBG; n = 10) or aortic valve replacement (AVR; n = 15) were studied pre- and postoperatively with neuropsychiatric testing. Results were related to the number of MES noted intraoperatively. In addition, we registered the intraoperative changes of middle cerebral artery blood flow velocity, mean arterial pressure, arterial blood gases, haemoglobin and haematocrit. Statistics included t-test, two-way analysis of variance, Mann-Whitney-U-test and Spearman correlation with p < 0.05 considered significant. RESULTS Regarding demographic data and intraoperative parameters, both study groups (ACBG vs. AVR) were comparable except for age. AVR patients showed significantly more MES than those undergoing ACBG (p < 0.012) which was most pronounced in the late state of surgery (aortic clamp off; p < 0.0003). However, MES counts did not correlate with neuropsychiatric test results. CONCLUSIONS In contrast to recent reports, we were unable to show a deterioration of postoperative neuropsychiatric state related to high intraoperative MES count in our patients. Future TCD studies should focus on the differentiation between gaseous emboli and particles even in the clinical setting, as the latter may well play a major role for the development of cerebral dysfunction following cardiac surgery and extracorporeal circulation.

Background In patients with carotid artery disease, poor intracerebral collateralization is reflected by impaired cerebrovascular reactivity to carbon dioxide inhalation, which will improve after endarterectomy. The relationship between preoperative reactivity to carbon dioxide using transcranial Doppler sonography (TCD) and intraoperative changes of somatosensory evoked potentials (SEP) and TCD parameters were investigated. Methods In 94 patients, preoperative carbon dioxide reactivity was examined and defined impaired if mean blood flow velocity in the middle cerebral artery (Vm-MCA) increased less than 1.5% mmHg during carbon dioxide challenge. Patients then underwent 100 carotid operations under general anesthesia with both SEP and TCD monitoring. Shunts were placed if SEP amplitude decreased to less then 50% of control or central conduction time increased by 20% after clamping (critical SEP changes). TCD changes were defined as critical in case of a postclamping/preclamping Vm-MCA ratio < or = 0.4. The incidence of critical SEP and TCD changes was compared to preoperative carbon dioxide testing using Fisher's exact test with P < 0.05 considered significant. Postoperatively, neurologic state and carbon dioxide responsiveness were re-examined. Results Twelve patients showed impaired preoperative carbon dioxide reactivity on the side of operation, which improved markedly after surgery. The incidence of critical SEP changes in these cases (8.3%) was not significantly different from that in the remaining patients (14.8%). Critical SEP changes were significantly correlated with critical TCD changes (P < 0.0001). Conclusions Patients with poor carbon dioxide reactivity (preoperative TCD testing) did not have an increased risk of cerebral ischemia during carotid surgery, as assessed by intraoperative SEP recording.

Background Since 2007, we have performed 14 AB0-incompatible (AB0i) living kidney transplantations to increase the number of living kidney transplantations. Methods To prevent clotting, donor kidneys were perfused with an HTK/heparin solution with heparin washed out immediately pretransplantation. However, in 4/14 recipients, significant postoperative diffuse hemorrhage occurred with the need for surgical intervention in 3 patients. To analyze the cause of postoperative diffuse bleeding, sequentially before and after opening the graft anastomosis, we prospectively performed coagulation studies: partial thromboplastin time (PTT), thrombin time, thromboplastin time, fibrinogen, antithrombin, d - dimers, plasminogen, and thrombelastography. Results We found no clotting disturbances owing to blood group–specific immunoadsorption. However, 3/4 patients with bleeding complications showed elevated PTT values even 2 hours after opening the anastomosis, which was proven to be a heparin effect by in vitro application of heparinase. Hyperfibrinolysis and disturbances of platelet aggregation were not detected. Because of these results, we lowered the heparin dose administered after donor nephrectomy from initially 10,000–20,000 to 4000 IU resulting in significantly lower PTT values at 2 hours (34.6 ± 4.5 s among patients 6–14 vs 69.0 ± 16.3 s among patients 1–5; P = .012). There were no further bleeding complications. Lowering the heparin dosage had no impact on graft function: serum creatinine at discharge of 1.5 ± 0.1 versus 1.6 ± 0.2 mg/dL. Conclusion Our data indicated that postoperative hemorrhage after AB0i kidney transplantation was associated with the amount of heparin used for graft perfusion after donor nephrectomy. The use of antifibrinolytic agents may be harmful; no hyperfibrinolysis takes place in the AB0i transplant setting.

Neurologic, cardiologic, and dopplersonographic findings of 303 patients undergoing coronary bypass surgery were evaluated in a prospective study. About 5% of the patients suffered from a prior stroke. Nearly 9% had a significant stenosis of an internal carotid artery detected by dopplersonography. Central nervous system complications occurred in 18.2% of the patients, predominantly temporary mental disturbances. Old patients and those with complicating heart failure were at higher risk for mental disorders. Approximately 3% of the patients suffered from a stroke with a permanent deficit. Half of them had a potential source of cardiogenic embolism. The risk of a complicating stroke was raised by the presence of a stenosis of a carotid artery, a heart failure, or an arrhythmia. The frequency of peripheral nervous system complications was 13.5% with temporary symptoms in about half of the cases. Brachial plexus paresis predominated with a particular risk in mammaria bypass grafting.

Aim The hypothesis was that there is more undetected dysfunction of implanted pacemaker systems than that detected and corrected. This prompted a research project (sponsored by the German Research Foundation) to detect pacemaker abnormalities and evaluate their complications for patients, thus, proving or disproving the hypothesis. Methods and results Four hundred and fifteen pacemakers of deceased patients were analyzed assessing their functionality by in situ measurements and bench tests including five measurements and one telemetric interrogation. Results were divided into four categories and statistically evaluated. Life-threatening abnormalities were found in 3.8%, potentially life-threatening in 3.7%, probably symptomatic, divided into atrial and ventricular problems, 13.3% and 2.8%, respectively, and premature exhaustion in 1.2%. Three of 179 bipolar ventricular leads and 2 of 131 bipolar atrial leads had insulation defects corresponding to 1.7% and 1.5%, respectively. The bipolar complication rate was 2.8 times higher than unipolar. Conclusion The pacemaker patients investigated, living 4 years with their pacemaker on average, had a post-mortem evaluated complication rate of the category ''life-threatening'' of 3.8%. This result corresponds to an annual complication rate of 0.94% compared with a rate of only 0.39% in an earlier investigation.

The outcome of patients with penetrating heart injuries depends to a great extent on aggressive primary care and fast transport to the closest appropriate trauma center. There, after confirming the diagnosis, the injured victim has to be transferred without any delay to the operating room where the penetrating injury can be dealt with. The importance of resolute emergency management is shown based on a case presentation and a review of the current literature. The employment of extracorporal circulation (heart-lung machine) is rather subordinate in the primary care of these patients.

As pacing impedance is inversely related to pacing current, the increase of pacing impedance additionally decreases pacing current. Whether the impedance measurement at implantation predicts the outcome during follow-up, was studied in 87 patients who received the VDD-single lead UniPass 425 connected to the pacemaker Unity (Sulzer Intermedics). The impedance changes between implantation and 6 months follow-up were assessed for each patient. Similar impedance values were defined, if the two measurements were within a rangeor = -100 to +100 omega. Six-months impedance was lower or higher compared to implantation, if the difference exceeded-100 or+100 omega. At implantation, impedance was 535 +/- 98 omega (range: 333-811 omega) and significantly increased to 604 +/- 160 omega (range: 361-1150 omega) after 6 months. Mean difference between the two measurements was 69 +/- 162 omega (range: -336 bis + 560 omega). Similar impedance had 43 (implantation: 527 +/- 75 omega, 6 months: 531 +/- 87 omega), lower values 11 (implantation: 660 +/- 83 omega, 6 months: 494 +/- 73 omega) and higher values 33 patients (implantation: 503 +/- 99 omega, 6 months: 735 +/- 168 omega). Compared to the patients with similar impedance patients with lower impedance had a significantly higher impedance values at implantation.Pacing impedance increased significantly within 6 months after implantation. Pacing impedance changed100 omega in 51% of the patients. The long-term follow-up of pacing impedance can be predicted generally, but not for the individual patient.

Implantation of a VDD pacemaker (ventricular pacing; dual sensing [atrial and ventricular]; dual response [triggered + inhibited]) together with a single VDD electrode catheter restores synchronous AV ventricular stimulation in patients with higher-grade AV block and intact sinus function. If higher-frequency stimulation occurs it may be a sign of pacemaker malfunction or of inadequate pacemaker programming. This study was undertaken to determine, at first follow-up examination, in how many patients with a VDD pacemaker VVI stimulation occurred more than 5% of the time; how such patients differed from those with 5% or fewer VVI stimulations; and whether a changed program reduced the proportion of VVI stimulations.67 consecutive patients were tested 1 to 3 months after implantation of the Unity VDD pacemaker (Sulzer Intermedics). The frequency of VVI stimulations was determined via a diagnostic pacemaker memory store. After intermediate analysis, programming was optimized and the patients then re-tested 12 months after the initial implantation.At the first follow-up examination 54 patients had VVI stimulations ofor = 5% (0.5 +/- 0.9%) and 13 had5% of the time (19.8 +/- 10.7%). The two groups differed significantly from one another in their lower intervention frequency (or = 5% VVI stimulations: 47 +/- 6/min;5% VVI stimulations: 58 +/- 5/min). In particular, the pacemakers in patients with5% VVI stimulations had been significantly more often programmed to values of50/min. As a result, the pacemakers of these patients were reprogrammed to a lower frequency. A year after implantation there was no longer any difference in the lower intervention frequency, 44 +/- 4/min, between patients with initially5% VVI stimulations and those with initiallyor = 5% stimulations. At the same time, the proportion of VVI stimulations fell to 4 +/- 6%, with 67% of patients having AV synchronicity of95%.At first follow-up, patients with5% VVI stimulations differed from those withor = 5% stimulations with regard to an increased lower intervention frequency. In most of these patients the proportion of AV stimulations was increased to95% by reducing the lower intervention frequency toor = 50/min.

The endothelium appears to play an important role in the regulation of intravascular coagulation. Thrombomodulin is one of the anticoagulant substances that is expressed by endothelial cells. The influence of age and illness on the thrombomodulin-protein C system was studied prospectively in 80 cardiac surgery patients. Patients70 yr old (n = 20) were compared with patients50 yr (n = 20) (group I), and patients undergoing a simple cardiac procedure (n = 20) were compared with patients scheduled for complex surgery (n = 20) (group II). Thrombomodulin (normal40 ng ml-1), protein C and (free) protein S plasma concentrations were measured by enzyme-linked immunosorbent assays (ELISA) after induction of anaesthesia (baseline values), during and after cardiopulmonary bypass (CPB), at the end of surgery, 5 h after CPB and on the first day after operation. Blood loss and use of homologous blood and blood products were significantly greater in patients70 yr and in those undergoing complex surgery. At baseline, thrombomodulin concentration was increased in patients undergoing complex surgery (mean 52 (sd 9) ng ml-1). After bypass and after operation, thrombomodulin increased most in patients70 yr (from 40 (8) to 78 (10) ng ml-1) and in those patients who underwent complex cardiac operations (from 52 (8) to 79 (10 ng ml-1) (P0.05). Changes in protein C and protein S concentrations were similar in all groups. On the first day after operation only, protein C concentrations were reduced in patients70 yr and in patients who underwent complex cardiac surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac operations using cardiopulmonary bypass (CPB) are associated with a systemic inflammatory response most likely attributable to the release of various inflammatory mediators and activation of complement or coagulation cascade. In addition, (circulating) adhesion molecules, such as endothelial leukocyte adhesion molecule (ELAM-1), vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1), appear to be of central importance in the CPB-related inflammatory process. In this situation, antiproteases, such as aprotinin, may help to prevent damage of endothelial integrity. In a prospective study, 40 consecutive patients undergoing elective cardiac operation were randomly divided into two groups (with 20 patients in each group): in group 1 "high-dose" aprotinin was used (2 million IU of aprotinin before CPB, 500,000 IU/h until end of operation, 2 million IU added to the prime) (with aprotinin), and in group 2 no aprotinin was given (without aprotinin). Circulating adhesion molecules (cICAM-1, cELAM-1, and cVCAM-1) were measured from arterial blood samples using ELISA after induction of anesthesia (baseline), during CPB, at the end of the operation, 5 hours after CPB, and on the first postoperative day. The two groups were comparable concerning their biometric profile and CPB data. Baseline values of circulating adhesion molecules were within normal range and similar in both groups. During CPB, hemodilution resulted in a decrease in all circulating adhesion molecules. On the first postoperative day, cICAM-1 (with aprotinin, 215 +/- 32 ng/mL; without aprotinin, 230 +/- 40 ng/mL) and cELAM-1 (with aprotinin, 28 +/- 6 ng/mL; without aprotinin, 31 +/- 6 ng/mL) returned to baseline values.(ABSTRACT TRUNCATED AT 250 WORDS)

The purpose of this retrospective study is the analysis of dysrhythmias following internal cardioversion/defibrillation of ventricular tachycardia (VT) or fibrillation (VF) and to discuss their relevance to the therapy with automatic implantable devices. Therefore, 304 internal conversions of VT/VF during and/or after implantation of automatic defibrillators were evaluated in 51 patients. Significant post-shock arrhythmias (bradycardia, atrial fibrillation, non-sustained VT ofor = 10 cycles) were absent after 89% of internal shocks. Pauses of2 s were observed in 2/9 patients without VVI-back-up pacing. The heart rate wasor = 50 bpm in 10/51 patients. Atrial fibrillation occurred in 7 patients. Non-sustained, mostly polymorphic VT consisting ofor = 10 cycles followed 18/304 (6%) internal shocks in 13 patients. The VT rate wasor = 200/min in 17/18 episodes and triggered an inadequate shock once. The incidence of non-sustained VT post-shock was unrelated to shock energy, type, and duration of the converted arrhythmia. In conclusion, automatic implantable devices should provide back-up pacing. Tachycardic rhythms can mislead automatic interpretation of the effect of internal shocks.

In patients suffering from constrictive pericarditis, the best hemodynamic results can be achieved by total mobilization of the heart and complete resection of the pericardium. Among 72 patients operated upon from 1969 to 1991, the use of extracorporeal circulation became necessary only twice. Therefore, we suggest the use of heart lung machine only in patients with bad myocardial function or in patients who need correction of additional diseases. Routine use of extracorporeal circulation is not mandatory.

Bei der Perikarditis constrictiva ist nur durch eine vollstandige Mobilisation des Herzens und eine weitgehende Resektion des Herzbeutels eine hamodynamische Besserung zu erreichen. Unter 72 operierten Fallen haben wir nur zweimal den Einsatz der Herz-Lungen-Maschine fur notwendig erachtet. Wegen der notwendigen Heparinisierung und der damit verbundenen Nachteile lehnen wir den Routineeinsatz der extrakorporealen Zirkulation ab. Der Einsatz der HLM ist sinnvoll bei sehr schlechter Myokardfunktion und notwendig zur Korrektur begleitender Erkrankungen.

Transcranial Doppler sonography (TCD) was used to determine the mean blood flow velocity of the middle cerebral artery (Vm-MCA) and pulsatility (systolic/diastolic flow velocity = S/D) in 25 patients undergoing aortocoronary bypass grafting before, during, and after extracorporeal circulation (ECC). Preoperatively, none of the patients had signs or symptoms of cerebrovascular disease. ECC was performed with 2.4 l/min per m2 under mild hypothermia (34 degrees C) using membrane oxygenators. After 20 min of nonpulsatile perfusion, ECC was switched to the pulsatile mode for 20 min. Nonpulsatile perfusion was applied for the remaining ECC period. Vm-MCA, S/D, mean arterial blood pressure (MABP), and nasopharyngeal temperature (T.np) were recorded continuously throughout the operation. Hematocrit and paCO2 were determined before, during, and after ECC. Following hemodilution after the introduction of ECC, Vm-MCA was significantly increased compared with the baseline values before ECC. With hematocrit and paCO2 varying insignificantly during ECC, the onset of pulsatile ECC decreased Vm-MCA and MABP simultaneously. After the re-establishment of nonpulsatile ECC, both Vm-MCA and MABP increased again. However, a linear relationship between the two variables could not be documented statistically. During pulsatile ECC, pulsatility (S/D) of the obtained TCD wave forms did not reach baseline values. In 4 cases, TCD showed cessation of diastolic blood flow velocity after induction of ECC or onset of pulsatile ECC. An increase in MABP or changes in ECC regimen promptly restored diastolic TCD signals in these cases. Our results support the concept of increased cerebral blood flow under mild hypothermic ECC. Compared with the nonpulsatile perfusion mode, we found Vm-MCA reduced during pulsatile ECC.(ABSTRACT TRUNCATED AT 250 WORDS)

Neurologic, cardiologic, and dopplersonographic findings of 303 patients undergoing coronary bypass surgery were evaluated in a prospective study. About 5% of the patients suffered from a prior stroke. Nearly 9% had a significant stenosis of an internal carotid artery detected by dopplersonography. Central nervous system complications occurred in 18.2% of the patients, predominantly temporary mental disturbances. Old patients and those with complicating heart failure were at higher risk for mental disorders. Approximately 3% of the patients suffered from a stroke with a permanent deficit. Half of them had a potential source of cardiogenic embolism. The risk of a complicating stroke was raised by the presence of a stenosis of a carotid artery, a heart failure, or an arrhythmia. The frequency of peripheral nervous system complications was 13.5% with temporary symptoms in about half of the cases. Brachial plexus paresis predominated with a particular risk in mammaria bypass grafting.

Polytetrafluorethylene (PTFE) prostheses were implanted in 12 sheep as a shunt between the carotid artery and the jugular vein using an end-to-side anastomosis technique. This technique allows repeated tests of the pharmacological and toxicological safety of artificial kidney units after both single and multiple administration. Further-more, it enables the investigation of detoxification of compounds via dialysis, thus contributing to drug safety. Implantation of the prosthesis was uncomplicated. Connection to the extracorporeal circulation was achieved via catheters and maintained using a pump with an output of up to 300 ml/min. This enabled maintenance of extracorporeal circulation for several hours without clinical impairment to the animals. The AV-shunts remained functional for between 8 and 253 days (mean 112·3 days).

In the sixties and early seventies several authors reported neurological complications following open-heart surgery. A primary matter of discussion was valid preoperative investigation aimed at preventing neurological complications among the increasing number of patients undergoing elective coronary artery bypass grafting (CABG). Controversy exists as to whether patients with asymptomatic carotid bruits have an increased risk of perioperative stroke at the time of cardiac surgery, especially when prolonged hypotension occurs. Moreover, perioperative strokes often occur in patients who were not suspected of having carotid disease. Furthermore, significant carotid occlusive disease may be present without signs or symptoms, and thus remain undiagnosed.

BACKGROUND: In patients with carotid artery disease, poor intracerebral collateralization is reflected by impaired cerebrovascular reactivity to carbon dioxide inhalation, which will improve after endarterectomy. The relationship between preoperative reactivity to carbon dioxide using transcranial Doppler sonography (TCD) and intraoperative changes of somatosensory evoked potentials (SEP) and TCD parameters were investigated. METHODS: In 94 patients, preoperative carbon dioxide reactivity was examined and defined impaired if mean blood flow velocity in the middle cerebral artery (Vm-MCA) increased less than 1.5% mmHg during carbon dioxide challenge. Patients then underwent 100 carotid operations under general anesthesia with both SEP and TCD monitoring. Shunts were placed if SEP amplitude decreased to less then 50% of control or central conduction time increased by 20% after clamping (critical SEP changes). TCD changes were defined as critical in case of a postclamping/preclamping Vm-MCA ratio < or = 0.4. The incidence of critical SEP and TCD changes was compared to preoperative carbon dioxide testing using Fisher's exact test with P < 0.05 considered significant. Postoperatively, neurologic state and carbon dioxide responsiveness were re-examined. RESULTS: Twelve patients showed impaired preoperative carbon dioxide reactivity on the side of operation, which improved markedly after surgery. The incidence of critical SEP changes in these cases (8.3%) was not significantly different from that in the remaining patients (14.8%). Critical SEP changes were significantly correlated with critical TCD changes (P < 0.0001). CONCLUSIONS: Patients with poor carbon dioxide reactivity (preoperative TCD testing) did not have an increased risk of cerebral ischemia during carotid surgery, as assessed by intraoperative SEP recording.

Anastomoses or reconstructions at the trachea are known to be related to a high risk of complications. Simi larly, anastomoses at smaller vessels have often occasioned discussion con cerning new techniques and different suturing materials. Low-dose laser energy seems to offer a new chance of tissue welding in these areas. In 10 Beagle dogs tracheal anastomoses were performed with an argon laser system, stabilized only by three single sutures for readaptation of the stumps. In 5 dogs even these three su tures were removed immediately af ter the tissue welding was finished. The anastomoses were monitored by bronchoscopy after an interval of six weeks and were removed after twelve weeks for pathologic investigations. In another 5 dogs carotid arteries were transected and reanastomosed with a similar technique. Readapta tion was achieved by four single su tures at equal distance, which were left in situ. Patency was monitored by Doppler ultrasound and by angiogra phy, and again after an interval of four to six weeks the anastomotic seg ments were resected and examined pathologically. All animals showed an uneventful postoperative course. None of the tracheal anastomoses showed any signs of functional impairment, air leakage, or infection. Bronchoscopy revealed no significant luminal nar rowing. These findings were con firmed after resection. Histology showed regular wound healing and especially normal reconstruction of the ciliated endothelium of the tra chea. Similarly all carotid anasto moses were patent in Doppler ultrasound and angiographic con trols. Neither angiography nor direct inspection after resection revealed signs of aneurysm formation. Micro scopic investigations showed a smooth endothelial passage between the two anastomosed segments and regular wound healing of the arterial wall. There were no signs of excessive scar formation or intimal hyperpla sia. The results underline the applica bility of laser energy for the perform ance of anastomoses at the tracheobronchial tree, as well as at smaller vessels. Clinical application has to be preceded by further investi gations and some technical improve ments, but still the technique shall prove to be an alternative to conven tional suturing techniques for se lected cases in the near future.

A 38 year old male patient presented with a cardiac tumor. Echocardiography and visualization of the left atrium revealed a large myxoma. Surgical resection of the tumor was performed with the aid of cardiopulmonary bypass. The extensive size of the tumor base and its localisation at the posterior left atrial wall made a conventional approach impossible. Therefore radical resection of the tumor was undertaken using autotransplantation. After a routine postoperative course, the patient was discharged on the twenty seventh hospital day.

This paper describes the results of treatment of 15 patients with inferior vena cava thrombosis. Thrombolysis using urokinase was the method of choice (12 patients) unless there were contraindications when thrombectomy (three patients) was performed. Thrombolytic therapy produced complete clearance of the inferior vena cava in eight of the 12 patients and partial clearance in the remaining four. Thrombolysis was terminated because of minor bleeding complications in four. Thrombectomy was done in three patients in whom there were contraindications to thrombolytic therapy. We believe that thrombolysis is a feasible method of treatment and possibly the method of choice when the thrombus is older than 3 days and the patient's general state is poor.

In a consecutive series of 150 patients who underwent open heart surgery, absorbable suture (PDS-Ethicon) were used for the closure of median sternotomy. One patient developed sternal dehiscence; wound complications or incompatibility with the suture material did not occur. With the technique of "double" PDS sutures, rapid and secure sternal closure can be performed even in cases of friability of the sternum without cutting through the sternal bone.

Tracheal anastomoses are known to be related to special surgical risks. We performed laser-assisted trachea anastomoses in 10 Beagle dogs, using an Argon-laser system and a handheld quarz fiber for energy transmission. All animals showed an uneventful postoperative course without signs of infection, air-leakage or respiratory impairment. Pathologic examination revealed no significant stenosis but a normal reconstruction of the tracheal endothelium and a normal woundhealing with only an increased connective tissue reaction. Because of the lower tensile strength of laser-assisted anastomoses in general, three adapting absorbable sutures should be left in situ to increase the resistance against mechanical stress. Under these circumstances laser-assisted anastomoses seem to be a promising additional method in the field of tracheal reconstruction and transplantation.

Bei Patienten mit diffuser coronarer Herzkrankheit ergibt sich nicht selten die intraoperative Notwendigkeit zur Durchfuhrung einer Endarteriektomie (EA), um eine Bypassanlage zu ermoglichen und gleichzeitig eine komplette Revascularisation zu gewahrleisten. Besonders haufig ist das System der rechten Kranzarterie von derart langstreckigen und diffusen Veranderungen betroffen.

Pulsatile wave patterns in basal cerebral arteries were studied by means of transcranial Doppler ultrasound (TCD) in 11 patients undergoing cardiopulmonary bypass (CPB) surgery. Different physiological states and technical parameters were demonstrated influencing wave forms delivered from a pulsatile CPB roller pump. The results gave evidence of the variability of pulsatile perfusion which may explain the inconsistency in the literature concerning its effectiveness in preserving tissue function. TCD proved to be a useful approach to define pulsatility of cerebral blood flow during CPB.

Weit verbreitete und ausgereifte diagnostische Masnahmen, wenig belastende Narkoseverfahren, standardisierte Operationstechniken und modernste intensivmedizinische Therapieverfahren haben dazu gefuhrt, das die chirurgische Behandlung der in den letzten Jahren standig zunehmenden koronaren Herzkrankheit heute einen wesentlichen Teil unserer operativen Tatigkeit beansprucht. Seit mehreren Jahren sind etwa zwei Drittel aller mit der Herz-Lungen-Maschine durchgefuhrten Operationen an der Giesener Klinik fur Herz- und Gefaschirurgie Eingriffe am Koronarsystem.

Vor- und Nachteile pulsatiler und nichtpulsatiler Perfusionsverfahren der extrakorporalen Perfusion sind seit Jahren Gegenstand kontroverser Diskussionen (Philbin et al. 1982; Mavroudis 1978). Die als unphysiologisch erachtete nichtpulsatile Stromung soll den Stromungswiderstand erhohen, den kapillaren Blutflus storen, Herzund Nierenfunktion beeintrachtigen sowie weitere homoostatische und endokrine Nebeneffekte haben (Ubersicht s. Edmunds 1982).