Perfusion  2002 Jul;17(4):305-12 

Circulatory support for OPCAB procedures.

Mueller XM, von Segesser LK.

Clinic for Cardiovascular Surgery, Centre Hospitalier Universitaire Vaudois,
Lausanne, Switzerland. xavier.mueller@chuv.hospvd.ch

During off-pump coronary artery bypass grafting (OPCAB) which allows complete
revascularization through a median sternotomy, revascularization of the lateral
and posterior walls requires the verticalization of the heart, which may cause
haemodynamic disturbance. This concern has stimulated the development of
circulatory support with mini-pumps. Initially, these pumps were designed for
the right side of the heart, which was found to be the main contributor to
haemodynamic instability under experimental conditions. The three types of
mini-pumps that have been developed so far - two for the right side of the heart
and one for both sides - are reviewed as well as a new concept of integrated
cardiopulmonary bypass (CPB) circuit with reduced surface and priming volume.
However, with increasing experience and improved methods of exposition, OPCAB
has become a procedure that can be performed without support in the majority of
the cases. Nevertheless, the concept of miniaturization and the possibility to
insert these devices through a peripheral access has opened the way to new
indications, mainly short-term circulatory support for acute heart failure. This
development is welcome in a field where available devices are invasive and
plagued with a heavy morbidity.

Ann Thorac Surg  2002 Jul;74(1):139-42 

Duroflo II heparin bonding does not attenuate cytokine release or improve
pulmonary function.

Butler J, Murithi EW, Pathi VL, MacArthur KJ, Berg GA.

Department of Cardiac Surgery, Western Infirmary, Glasgow, Scotland, United
Kingdom. gilmour.wendy.wg@northglasgow.scot.nhs.uk

BACKGROUND: Comparison of the cytokine generation and leukocyte activation
properties of Duroflo II heparin bonded bypass circuit (Baxter Healthcare Corp,
Compton, UK) and the conventional cardiopulmonary bypass circuit. Attempt to
correlate these to pulmonary dysfunction postoperatively. METHODS: Forty
patients undergoing elective, isolated coronary artery bypass grafting were
randomly allocated to have either plain extracorporeal circuits (group C) or
heparin bonded extracorporeal circuits (group H). Full systemic heparinization
was used in all patients. The inflammatory response was assessed by measuring
plasma levels of interleukin-6, interleukin-8, interleukin-10, and
polymorphonuclear elastase. Gas exchange was assessed by measuring the PaO2/FIO2
ratio. RESULTS: Significant impairment of oxygenation was seen in both groups
with the lowest values at the end of the operation before a gradual return to
normal during the next 6 hours. There were no differences between the groups in
gas exchange or times to extubation. There were significant elevations in all
the cytokines, with interleukin-6 levels peaking at 4 hours in group H and 24
hours in group C, before starting to return to normal at 48 hours. The patterns
of interleukin-8 and interleukin-10 rise were identical in the two groups.
Polymorphonuclear elastase reached a peak at the end of the operation in group H
and remained elevated up to 24 hours, whereas levels continued to rise in group
C up to 4 hours. There were no significant differences in levels between groups
at any time. There were no differences between the groups in blood loss or blood
product usage. CONCLUSIONS: Cardiopulmonary bypass induces a systemic
inflammatory response with release of cytokines and activation of leukocytes.
This correlates with the severe deterioration in pulmonary gas exchange from
preoperative levels up to 6 hours postoperatively (p < 0.05). In the presence of
systemic heparinization, Duroflo II heparin bondingtf the circuits has minor
effects on the pattern of evolution of this inflammatory response.

Ann Thorac Surg  2002 Jul;74(1):115-8 

Off-pump coronary artery bypass grafting decreases morbidity and mortality in a
selected group of high-risk patients.

Bittner HB, Savitt MA.

Division of Cardiothoracic Surgery, University of Minnesota, Minneapolis 55455,
USA. bittn006@tc.umn.edu

BACKGROUND: The ideal indication for off-pump coronary artery bypass grafting
(OPCABG) has yet to be defined. High-risk surgical patients may benefit the most
when cardiopulmonary bypass (CPB), aortic cross clamping, and cardioplegic
arrest are avoided. The aim of this study was to determine whether off-pump
coronary artery bypass grafting might decrease the operative morbidity and
mortality in a select group of high-risk patients with multivessel coronary
artery disease. METHODS: Utilizing a Parsonnet risk stratification model we
analyzed prospectively collected data on a cohort of high-risk coronary artery
disease patients, which were operated on with beating-heart technology by the
same group of surgeons in a tertiary care university medical center. High-risk
patients were defined as those with a Parsonnet score of 15 or greater. RESULTS:
Fifty-seven multivessel disease OPCABG patients (over a period of 2 years) had
markedly increased Parsonnet scores (24.3 +/- 10.6). The average ejection
fraction of the patients was 42% (+/-12.3) and their age ranged from 52 to 85
years (mean 70.6 +/- 10.4, 26% women). Unstable angina was present in 42
patients (74%) and 10 patients underwent OPCABG within 24 hours of the
occurrence of acute myocardial infarction. In addition to severe coronary artery
disease 32% of the patients presented with congestive heart failure,
insulin-dependent diabetes (18%), renal failure (22%), peripheral vascular
disease (31%), pulmonary disease (18%), and neurologic disorders (14%). An
average of 2.6 +/- 0.9 grafts/patient were performed and the posterior
descending artery or marginal branches of the circumflex artery or both were
grafted in 90%. The 30-day mortality rate was 3.5% (n = 2). CONCLUSIONS: OPCABG
can be performed with a reasonable low morbidity and mortality in this select
group of high-risk patients. OPCABG is a reasonable, and might even be
preferable, operative strategy in this high-risk group of patients.

Med Sci Monit  2002 Jul;8(7):MT118-23 

Robotically-assisted coronary artery surgery with and without cardiopulmonary
bypass - from first clinical use to endoscopic operation.

Detter C, Boehm D, Reichenspurner H, Deuse T, Arnold M, Reichart B.

Department of Thoracic and Cardiovascular Surgery.

BACKGROUND: Recently, the ZEUS(tm) Robotic Surgical System has been introduced
to increase the precision of endoscopic cardiac surgery. This study investigated
its clinical use for endoscopic coronary artery bypass grafting.
Material/Methods: Between 1998 and 2001, 41 patients with single and multivessel
disease were operated on using the ZEUS(tm) system. The robotic system was
introduced step by step into clinical practice. Initially, the system was used
only for endoscopic internal mammary artery (IMA) harvest (n=12), later for
coronary anastomoses on the arrested (n=13) or beating heart after median
sternotomy (n=6), and finally for endoscopic coronary bypass grafting on either
the arrested (n=2) or beating heart (n=8). RESULTS: Endoscopic IMA harvest
ranged from 48 to 110 min and was completed in all cases. In the sternotomy
group, the robotic anastomosis time averaged 21 min on the arrested and 25 min
on the beating heart, respectively (n.s.). In the endoscopic cases, the average
time for endoscopic anastomosis was 41 min on the arrested and 36.5 min on the
beating heart (n.s.), with an overall duration of surgery between 4.0 and 8.0
hours. One endoscopic case was intraoperatively converted to a MIDCAB procedure
with manual anastomosis. The total patency rate of all graft anastomoses,
confirmed by early postoperative angiographic control, was 97%. One patient
underwent reoperation with an uneventful postoperative course. CONCLUSIONS: The
present study demonstrates the feasibility of endoscopic coronary
revascularization using a computer-assisted surgical robotic system on the
arrested and beating heart in selected patients.

Med Sci Monit  2002 Jul;8(7):CR467-72 

Plasma soluble L-selectin following cardiopulmonary bypass (CPB) in children: is
it a marker of the postoperative course?

Dagan O, Prince T, Ben-Abraham R, Vidne B, Mishaly D, Katz Y, Keller N, Barzilay
Z, Paret G.

Department of Pediatric Cardiac Critical Care, Schneider Medical Center, the
Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.

BACKGROUND: There is increasing evidence that cytokine-inducible
leukocyte-endothelial adhesion molecules are instrumental in the postoperative
inflammatory response following cardiopulmonary bypass (CPB). L-selectin was
shown to be one of those neutrophil-endothelial cell adhesion molecules. This
study aimed to investigate the relationship of the soluble adhesion molecule,
sL-selectin, and the postoperative course in children undergoing CPB.
Material/Methods: To determine the time course of sL-selectin after CPB, serial
blood samples of 9 children undergoing CPB were collected from the arterial line
or from the bypass circuits preoperatively, on initiation of CPB and 1, 6, 12,
18, 24, and 48 hours postoperatively. Plasma was recovered immediately,
aliquoted and frozen at -70 degrees C until use. Circulating sL-selectin
molecules were measured with a sandwich enzyme-linked immunoabsorbent assay
(ELISA) technique. There were significant changes in plasma levels of
sL-selectin in patients following CPB, and these levels were associated with
patient characteristics, operative variables and postoperative course. Low
values of sL-selectin significantly correlated with inotropic support, low PRISM
score, postoperative hypotension and fever. There was a significant association
between the development of postoperative sepsis and low sL-selectin levels. No
correlation was found between sL-selectin values and lactate concentration or
neutrophil count. CONCLUSIONS: Our results suggest a relation between
CPB-induced mediators and both early and late clinical effects. Although the
mechanism for the changes of sL-selectin remains undetermined, the
down-regulation of sL-selectin indicates neutrophil activation and supports the
possibility that anti-adhesion therapies might participate in the prevention and
treatment of the inflammatory response associated with CPB.

Arch Neurol  2002 Jul;59(7):1090-5 

Comment in:
 Arch Neurol. 2002 Jul;59(7):1074-6.

Brain damage after coronary artery bypass grafting.

Bendszus M, Reents W, Franke D, Mullges W, Babin-Ebell J, Koltzenburg M,
Warmuth-Metz M, Solymosi L.

Department of Neuroradiology, University of Wurzburg, Josef-Schneider-Strausse
11, D-97080 Wurzburg, Germany. bendszus@neuroradiologie.uni-wuerzburg.de

BACKGROUND: Coronary artery bypass grafting (CABG) is associated with a risk for
focal neurological deficits and neuropsychological impairment postoperatively.
OBJECTIVES: To examine the brain damage after CABG using diffusion-weighted
magnetic resonance imaging and (1)H-magnetic resonance spectroscopy (MRS) and to
correlate the results with neurological and neuropsychological findings.
PATIENTS AND METHODS: Thirty-five consecutive patients undergoing elective CABG
were included. Patients underwent a neurological and neuropsychological
examination before and after CABG. The magnetic resonance protocol was applied
before and after (mean, 3 days) surgery and included a diffusion-weighted
sequence and single-voxel MRS measurements in the frontal lobes. RESULTS: None
of the patients revealed a new focal neurological deficit after surgery.
Diffusion-weighted magnetic resonance imaging demonstrated new ischemic lesions
in 9 (26%) of the patients. The presence of an ischemic lesion was not related
to impaired postoperative test performance (P>.50). The apparent diffusion
coefficient values in the cerebellum and the centrum semiovale exhibited an
increase after surgery (P<.01), consistent with vasogenic edema. Following
surgery, MRS revealed a significant decrease in the metabolite ratio of
N-acetylaspartate-creatine (mean +/- SD, 1.69 +/- 0.20 vs 1.52 +/- 0.19;
P<.001). The extent of deterioration in neuropsychological test performance
after surgery was closely related to the degree of the
N-acetylaspartate-creatine ratio decrease (P<.01). A follow-up MRS scan revealed
a normalization of the N-acetylaspartate-creatine ratio, which accompanied the
recovery in psychological test performance. CONCLUSIONS: Postoperative
impairment in neuropsychological test performance is associated with a transient
metabolic neuronal disturbance. Focal ischemic lesions after CABG are more
frequent than the apparent neurological complication rate; however, they are not
related to the diffuse postoperative encephalopathy.

Eur J Cardiothorac Surg  2002 Jul;22(1):106-111 

Dopamine therapy for patients at risk of renal dysfunction following cardiac
surgery: science or fiction?

Woo EB, Tang AT, El Gamel A, Keevil B, Greenhalgh D, Patrick M, Jones MT, Hooper
TL.

Department of Cardiothoracic Surgery, Wythenshawe Hospital, Southmoor Road, M23
9LT, Manchester, UK

OBJECTIVES: We aimed to evaluate the renoprotective role of renal-dose dopamine
on cardiac surgical patients at high risk of postoperative renal dysfunction.
The latter included older patients or those with pre-existing renal disease,
elevated preoperative serum creatinine (Cr), poor ventricular function,
hypertension, diabetes mellitus and unstable angina requiring intravenous
therapy. METHODS: Fifty patients undergoing cardiopulmonary bypass (CPB) who
fulfilled the entry criteria were prospectively randomized into two groups:
Group 1 received a 'renal-dose' (3 &mgr;g kg(-1) min(-1)) dopamine infusion
starting at anaesthetic induction for 48 h whilst saline infusion acted as
placebo in Group 2. The anaesthetic and CPB regimes were standardized. Urinary
excretion of retinol binding protein (RBP) indexed to Cr, an accurate and
sensitive marker of early renal tubular damage, was assessed daily for 6 days.
Additional outcome measures included daily fluid balance, blood urea and serum
Cr. Statistical comparisons were made using ANOVA and Mann-Whitney U-test.
RESULTS: No significant difference was found between the groups in their age,
gender, preoperative NYHA class, ejection fraction, baseline serum Cr and
duration of CPB and aortic cross-clamping. Renal replacement therapy was not
required in any instance. Both groups demonstrated a similar and significant
rise in urinary RBP throughout the study period. Dopamine-treated patients
achieved more negative average fluid balance than those on placebo (5 vs. 229
ml, P<0.05). CONCLUSIONS: Renal-dose dopamine therapy failed to offer additional
renoprotection to patients considered at increased risk of renal dysfunction
after CPB.

Eur J Cardiothorac Surg  2002 Jul;22(1):47-52 

Resection of advanced thoracic malignancies requiring cardiopulmonary bypass.

Vaporciyan AA, Rice D, Correa AM, Walsh G, Putnam JB, Swisher S, Smythe R, Roth
J.

The University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Boulevard,
77025, Houston, TX, USA

OBJECTIVES: Patients with malignancies involving cardiac structures have limited
therapeutic options and significant risk of mortality. The decision to offer
radical palliative or curative resection must be made only after consideration
of the substantial surgical risks. The purpose of this retrospective study was
to determine the feasibility and benefits of resection with cardiopulmonary
bypass (CPB) of metastatic or non-cardiac primary malignancies extending
directly into or metastasizing to the heart in select patients. Our results were
examined to assess the risks and benefits of such radical therapy. METHODS: We
retrospectively reviewed patient charts and identified all patients with
malignancies involving the cardiac chamber or great vessels (excluding renal
carcinomas with caval extension) or with substantial cardiac compression who had
undergone resection with CPB at The University of Texas M.D. Anderson Cancer
Center between January 1995 and July 2000. We evaluated demographic data,
symptomatology, tumor characteristics, and outcomes. RESULTS: Nineteen patients
(six males and 13 females; median age of patients, 47 years; age range, 17-67
years) were included in the study. Eleven patients underwent surgery with
curative intent, and eight underwent surgery with palliative intent. Seventeen
patients had tumors that required CPB because their tumors directly involved the
heart and/or great vessels (nine sarcomas, seven epithelial carcinomas, and one
unclassified), and two patients (both with sarcomas) required CPB to relieve
tumor tamponade. The technique included CPB (n=5), CPB with diastolic arrest
(n=12), and CPB with hypothermic circulatory arrest (n=2). Five patients
underwent concomitant pneumonectomy, and three underwent lobectomy. Two patients
(11%) died in the hospital after resection with palliative intent. Of the 11
patients who underwent resection with curative intent, ten (91%) had complete
resections. The median time in the intensive care unit was 5.3 days (range, 0-37
days) and the median length of hospital stay was 17.2 days (range, 0-107 days).
Major complications occurred in 11 patients (58%); the most common major
complications were pneumonia (n=7 patients), mediastinal hematoma (n=4
patients), and acute respiratory distress syndrome (n=2 patients). The median
follow-up duration was 27 months. The overall 1- and 2-year survival rates were
65 and 45%, respectively. CONCLUSIONS: Extensive thoracic tumors involving
cardiac structures can be resected with acceptable risk. When resection was
performed with curative intent, excellent 1- and 2-year cumulative survival
rates were achieved. Although resection with palliative intent was associated
with greater mortality rates, some patients survived for 1 and 2 years. The use
of CPB in selected patients with thoracic malignancies should be considered,
especially when complete resection can be achieved.

Anesth Analg  2002 Jul;95(1):26-30, table of contents 

The plasma supplemented modified activated clotting time for monitoring of
heparinization during cardiopulmonary bypass: a pilot investigation.

Koster A, Despotis G, Gruendel M, Fischer T, Praus M, Kuppe H, Levy JH.

Department of Anesthesia, Deutsches Herzzentrum Berlin, Charite, Campus Virchow,
Augustenburger Platz 1, 13353 Berlin, Germany. Koster@dhzb.de

The standard celite or kaolin activated clotting time (ACT) correlates poorly
with heparin levels during cardiopulmonary bypass (CPB). We compared a modified
kaolin ACT, in which plasma was supplemented, to a standard undiluted kaolin ACT
for monitoring heparin levels during CPB. Fifteen patients undergoing
normothermic CPB were enrolled in this prospective study. Heparin management was
performed according to the Hepcon HMS results (Medtronic, Minneapolis, MN). The
ACTs were performed with the ACT II device (Medtronic). Hepcon HMS calculations,
standard kaolin ACTs, and plasma supplemented modified ACTs (mACTs), prepared by
diluting blood samples 1:1 with human plasma (Behring, Marburg, Germany), were
measured every 30 min during CPB. The data obtained were correlated to the
plasma chromogenic anti-Xa activity as a reference assay for heparin levels. A
total of 64 samples were evaluated. The chromogenic anti-Xa activity ranged from
0.2 to 5.5 IU/mL. The Hepcon HMS calculations ranged from 2.7-8.2 IU/mL of
heparin, the standard ACT ranged from 424 to >999 s, and the mACT ranged from
210 to 801 s. The correlation to the chromogenic anti-Xa method was r = 0.43 for
the standard kaolin ACT and r = 0.69 for the plasma mACT. The plasma mACT
provided an improved correlation to chromogenically measured levels of anti-Xa
activity during CPB. The improved correlation most likely results from a
correction of the effects of the impairment of the coagulation system caused by
hemodilution and consumption of procoagulants on extracorporeal surfaces.
IMPLICATIONS: During cardiopulmonary bypass, the plasma modified kaolin
activated clotting time (ACT) provides a better correlation with heparin levels
than the standard kaolin ACT.