Ann Thorac Surg  2002 Nov;74(5):S1853-6; discussion S1857-63 

Surgical results of hemiarch replacement for acute type A dissection.

Ohtsubo S, Itoh T, Takarabe K, Rikitake K, Furukawa K, Suda H, Okazaki Y.

Department of Thoracic and Cardiovascular Surgery, Saga Medical School,
Saga-City, Japan. ootsubt2@post.saga-med.ac.jp

BACKGROUND: The appropriate surgical strategy for patients with an arch tear in
acute type A dissection remains controversial. We retrospectively compared
surgical results after hemiarch as compared with transverse aortic arch
replacement in patients with an arch tear in acute type A dissection. METHODS:
The records of 88 patients who consecutively underwent graft replacement for
acute type A dissection between 1989 and 2001 were reviewed. The patients were
divided into three groups: patients with ascending aortic replacement (group AS,
n = 41), those with hemiarch replacement (group HA, n = 23), and those with
transverse arch replacement (group AR, n = 24). Operative mortality and
morbidity and late outcome were compared among the three groups. RESULTS: The
overall early (30 day) mortality was 11.3% (10/88), and in-hospital mortality
was 14.7% (13/88). In-hospital mortality in groups AS, HA, and AR were 7.3%,
8.6%, and 33.3%, respectively (p = 0.011). Cardiopulmonary bypass, circulatory
arrest, and operation times were significantly shorter in group HA than in group
AR (p < 0.001). A smaller amount of intraoperative transfusion of red blood
cells (p = 0.0006) and fresh-frozen plasma (p = 0.0003) was needed in group HA
than in group AR, and postoperative bleeding during the first 24 hours
postoperatively was significantly less in group HA than in group AR (p =
0.0028). The incidence of postoperative coma did not differ among the three
groups (p = 0.89), nor did the incidence of postoperative patent false channel
in the descending thoracic aorta (p = 0.57). Actuarial survival rates after 5
years were significantly better in group HA (91.3% +/- 5.9%) than in group AR
(44.4% +/- 14.3%, p = 0.018). Freedom from reoperation on the distal aorta
within 5 years did not differ among the groups (p = 0.46). CONCLUSIONS: Hemiarch
replacement for acute type A dissection demonstrated favorable early and late
outcome. The extent of graft replacement influenced surgical mortality and
morbidity. Whenever the intimal tear is located in the lesser curvature of the
transverse arch, hemiarch replacement is recommended to improve overall
operative mortality and morbidity.

Rapid disappearance of protamine in adults undergoing cardiac operation with
cardiopulmonary bypass.

Butterworth J, Lin YA, Prielipp RC, Bennett J, Hammon JW, James RL.

Department of Anesthesiology, Wake Forest University School of Medicine,
Winston-Salem, North Carolina 27157-1009, USA. jbutter@wfubmc.edu

BACKGROUND: Despite long use of protamine in cardiac operations, neither
protamine concentrations nor pharmacokinetics have been reported in patients.
METHODS: Twenty-eight patients (age, 26 to 80 years) undergoing various cardiac
surgical procedures gave their consent to receive 250 mg of protamine sulfate
administered intravenously by an infusion pump during 5 minutes. Protamine was
administered at the usual intraoperative time after separation from
cardiopulmonary bypass for reversal of heparin. Timed arterial blood samples
were obtained after protamine infusion. Blood plasma was subjected to
solid-phase extraction and high-performance liquid chromatography. Total (free +
heparin-bound) protamine concentration versus time data were subjected to
pharmacokinetic modeling. RESULTS: Twenty-six patients completed the study.
Total plasma protamine concentrations declined rapidly. Model-independent
pharmacokinetic analysis revealed median (range) values as follows: volume of
distribution, 5.4 L (0.82 to 34 L); clearance, 1.4 L/min (0.61 to 3.8 L/min);
and half-life, 4.5 min (1.9 to 18 min). Schwarz-Bayesian criterion identified a
two-compartment exponential model with adjustment for weight in the central
compartment volume of distribution as performing better than other compartmental
or Michaelis-Menten models. CONCLUSIONS: Protamine has a very short
(approximately 5 minutes) half-life after a single 250-mg dose in adult
patients. This short half-life could underlie recurrent anticoagulation after
initial apparent reversal of heparin.

Kyobu Geka  2002 Nov;55(12):1021-5 

[A new formula to calculate perfusion rate in advanced hemodilution and tepid
cardiopulmonary bypass]

[Article in Japanese]

Higuchi H, Yoshii S, Osawa H, Suzuki S, Abraham SJ, Hosaka S, Shindo S, Tada Y.

Department of Surgery, University of Yamanashi, University Hospital, Yamanashi,
Japan.

BACKGROUND: During cardiopulmonary bypass, perfusion flow rate is generally
calculated only with the patient body surface. Recently, far advanced
hemodilution during cardiopulmonary bypass and tepid bypass circulation are
common. PURPOSE: We have arrived at an appropriate flow rate formula, in which
factors like temperature, hemoglobin concentration, the target mixed venous
oxygen saturation (SvO2), and the amount of oxygen consumption are included. Our
formula was compared with the conventional one. MATERIAL AND METHOD:
Seventy-four points of cardiopulmonary bypass data under total cardiopulmonary
bypass in 33 patients were studied. Our formula's validity was re-evaluated.
Then, the SvO2 values were predicted by applying the flow rate value as per
conventional calculation in to our formula. RESULTS: The flow rate of our
formula and the actual flow rate are well correlated (r = 0.9212). In the
prediction of the SvO2 by the conventional method, 36.5% were calculated to have
a SvO2 of less than 60%. Furthermore, with a hemoglobin concentration of 7 g/dl,
73.3% were calculated to have a SvO2 of less than 60%. With a body temperature
of 34 degrees centigrade, 53.8% were calculated to have a SvO2 of less than 60%.
On the other hand, to maintain SvO2 level at 70% by the conventional method, if
the patient hemoglobin concentration was 10 g/dl, temperature should be
maintained at 36 degrees centigrade, and when hemoglobin concentration is 7
g/dl, the temperature should be maintained at 33 degrees centigrade. CONCLUSION:
In advanced hemodilution or tepid cardiopulmonary bypass, use of appropriate
flow rate formula is recommended, which takes into account the indispensable
factors such as hemoglobin levels, temperature, and the target SvO2.

Circulation  2002 Nov 12;106(20):2601-7 

Preoperative glutamine administration induces heat-shock protein 70 expression
and attenuates cardiopulmonary bypass-induced inflammatory response by
regulating nitric oxide synthase activity.

Hayashi Y, Sawa Y, Fukuyama N, Nakazawa H, Matsuda H.

Department of Surgery, Osaka University Graduate School of Medicine, Suita,
Osaka, Japan. hayashi@surg1.med.osaka-u.ac.jp

BACKGROUND: Heat-shock protein 70 (HSP70) plays a major role in the
pathophysiology of inflammation, and the induction of HSP70 before the onset of
inflammation can reduce organ damage through a self-protective system. Glutamine
is known to be an inducer of HSP70, and its preoperative administration seems
useful in attenuating cardiopulmonary bypass (CPB)-induced inflammatory
response. METHODS AND RESULTS: Adult male Sprague-Dawley rats (group G, received
100 mg/kg of glutamine via the right jugular vein 3 times per day for 1 week and
just before the initiation of CPB; group C served as control) underwent CPB (60
minutes, 100 mL/kg per minute, 34 degrees C) and were killed 3 hours after the
termination of CPB. Group G showed significantly lower plasma concentrations of
interleukin-6 and interleukin-8 after CPB termination. Myocardial and
respiratory damages were significantly attenuated in group G, as evidenced by
Langendorff perfusion, respiratory index, and neutrophil adherence. HSP70
expressions in the heart, lung, and liver were detected only in group G before
CPB and were markedly stronger in group G 3 hours after CPB termination.
Although plasma nitrate+nitrite concentrations were not significantly different
between the groups, endothelial-constitutive nitric oxide synthase (NOS)
activity was markedly preserved and inducible NOS activity was markedly
attenuated in the tissues of group G. CONCLUSIONS: These results suggest that
preoperative glutamine administration induces HSP70 expression before CPB and
attenuates CPB-induced inflammation by regulating NOS activity, which may be a
prospective management for conferring tolerance to CPB-induced inflammatory
response through a self-protective mechanism.

Circulation  2002 Nov 12;106(20):2588-93 

Hypotension caused by extracorporeal circulation: serotonin from pump-activated
platelets triggers nitric oxide release.

Borgdorff P, Fekkes D, Tangelder GJ.

Laboratory for Physiology, Institute for Cardiovascular Research, Vrije
Universiteit Medical Center, Amsterdam, The Netherlands.
p.borgdorff.physiol@med.vu.nl

BACKGROUND: Cardiopulmonary bypass and hemodialysis often cause hypotension. We
investigated a possible role of pump-induced platelet activation with consequent
serotonin release. METHODS AND RESULTS: In rats, a heparin-coated extracorporeal
shunt was placed between the proximal part of a carotid artery and the distal
part of a femoral artery. Autoperfusion did not affect platelets or
hemodynamics. Pump perfusion, however, immediately elicited strong platelet
aggregation, whereas aortic pressure rapidly fell to 60+/-12% (mean+/-SD) of its
prepump value, partially recovered, and then progressively decreased to 70+/-12%
at 2 hours. Femoral resistance doubled and then decreased to 59+/-11%. The
initial changes in aortic pressure and femoral resistance were proportional to
the amount of platelet aggregation, were accompanied by a rise (6-fold) in
plasma serotonin levels downstream of the pump, but not in the aorta, and could
be mimicked by serotonin-infusion into the leg. All hemodynamic changes were
prevented or largely reduced by blockade of 5-hydroxytryptamine (5-HT)2
receptors with pizotifen or ritanserin. The hypotension and femoral resistance
decrease could also be prevented or abolished by inhibiting the production of
nitric oxide (NO), an intermediate in 5-HT(2B) receptor-induced vasodilation.
When the extracorporeal blood was pumped into the aortic arch instead of the
femoral artery, the hypotensive effect was similar and also NO dependent, but it
was absent with venous return. CONCLUSIONS: Pump perfusion with arterial return
of the blood causes hypotension by endothelial NO-release, which in turn is
triggered by serotonin from activated platelets.

Acta Anaesthesiol Scand  2002 Nov;46(10):1227-35 

Modulation of the inflammatory response to cardiopulmonary bypass by dopexamine
and epidural anesthesia.

Bach F, Grundmann U, Bauer M, Buchinger H, Soltesz S, Graeter T, Larsen R,
Silomon M.

Department of Anesthesiology and Critical Care Medicine, and Department of
Thoracic and Cardiovascular Surgery, University of Saarland, Homburg/Saarland,
Germany.

BACKGROUND: Cardiopulmonary bypass (CPB) induces a systemic inflammatory
reaction. Microcirculation-dependent alteration of the gut mucosal barrier with
subsequent translocation of endotoxins is a postulated mechanism for this
inflammatory response. This study was designed to elucidate whether two
different approaches to modulate splanchnic perfusion may influence systemic
inflammation to CPB. METHODS: We examined 40 patients scheduled for elective
coronary bypass surgery in a prospective, randomized study. One group (DPX)
received dopexamine (1 micro g. kg-1. min-1) continuously after induction of
anesthesia until 18 h after CPB. The control group (CON) received equal volumes
of NaCl 0.9% in a time-matched fashion. In a third group (EPI) a continuous
epidural infusion of bupivacaine 0.25% [(body height (cm) - 100). 10-1=ml.h-1]
was administered for the whole study period. Procalcitonin (PCT), tumor necrosis
factor (TNF-alpha), soluble TNF receptor, human soluble intercellular adhesion
molecule-1, C-reactive protein (CRP) and leukocyte count were measured as
parameters of inflammation. RESULTS: All parameters significantly increased
following CPB. Increases of PCT, TNF-alpha and leukocyte count were
significantly attenuated in the DPX and EPI groups at different time points.
However, neither splanchnic blood flow nor oxygen delivery and consumption were
different when compared with the CON-group. CONCLUSION: These results do suggest
that mechanisms other than an improved splanchnic blood flow by DPX and EPI
treatment have to be considered for the anti-inflammatory effects.

Circ J  2002 Nov;66(11):1068-9 

Surgical experience with right atrial-aortic fistula and penetration of the
superior vena cava by a protruding Accufix atrial J-shaped retention wire.

Kido M, Otani H, Kawaguchi H, Ninomiya H, Fujiwara S, Fujiwara H, Nakao Y, Sato
T, Imamura H.

Department of Thoracic and Cardiovascular Surgery, Kansai Medical University,
Osaka, Japan. kidom@takii.kmu.ac.jp

A 57-year-old woman who had a dual chamber pacemaker implanted in June 1990 for
sick sinus syndrome had developed heart failure since 1993. Although fluoroscopy
revealed that the proximal J-shaped retention wire of the lead had fractured and
had protruded through the outer insulation in 1994, and also that the distal
J-shaped retention wire of the lead had protruded through the outer insulation
in 1997, a transthoracic echocardiographic examination diagnosed tricuspid valve
regurgitation, suggesting that the right atrial-aortic fistula might have been
overlooked. In an attempt to avoid migration of the J-shaped retention wire from
the lead and to repair the tricuspid regurgitation, it was decided that an
operation be performed; however, intraoperative transesophageal echocardiography
showed a right atrial-aortic fistula. Intraoperative inspection also revealed
that the right atrial-aortic fistula and penetration of the superior vena cava
had been caused by the Accufix atrial J-shaped retention wire. Under total
cardiopulmonary bypass and induced cardiac arrest, a right atriotomy was
performed and the atrial and ventricular leads were removed from the tips. The
atrial orifice of the fistula and the aortic orifice were closed. Finally, a new
dual-chamber pacing system with bipolar epicardial pacing leads was implanted.
Postoperative inspection revealed that the proximal retention wire had
fractured, the tip of the retention wire had protruded through the outer
insulation, and the distal J-shaped outer insulation was damaged.

Anesthesiology  2002 Nov;97(5):1118-22 

Platelet PlA2 polymorphism and platelet activation are associated with increased
troponin I release after cardiopulmonary bypass.

Rinder CS, Mathew JP, Rinder HM, Greg Howe J, Fontes M, Crouch J, Pfau S, Patel
P, Smith BR;  Multicenter Study of Perioperative Ischemia Research Group.

Department of Laboratory Medicine, Yale University School of Medicine, New
Haven, Connecticut 06520-8051, USA. christine.rinder@yale.edu

BACKGROUND: The PlA2 polymorphism of platelet glycoprotein IIIa has been
identified as a prothrombotic risk factor in a number of cardiovascular
settings. The aim of this study was to determine whether the PlA2 polymorphism
of platelet glycoprotein IIIa and degree of platelet activation were associated
with more severe myocardial injury as indicated by troponin I release following
cardiopulmonary bypass. METHODS: The PlA2 genotype was determined in 66 patients
undergoing elective coronary artery bypass grafting requiring cardiopulmonary
bypass. Troponin I concentrations and the percentage of circulating, activated
(CD62P+) platelets were measured at predetermined intervals perioperatively.
RESULTS: Forty-six patients were Pl(A1,A1), and 20 were Pl(A1,A2) or Pl(A2,A2).
Patients with at least one PlA2 allele had significantly greater postoperative
troponin I concentrations than PlA1 homozygotes (P = 0.006, analysis of
variance). Peak troponin I concentrations also correlated significantly with the
increase in circulating, activated platelets (P = 0.02, Spearman rank
correlation). CONCLUSIONS: The PlA2 allele of platelet glycoprotein IIIa is
associated with higher troponin I concentrations following cardiopulmonary
bypass surgery, suggesting that this platelet polymorphism contributes to

Anesthesiology  2002 Nov;97(5):1110-7 

Synchronous rhythmical vasomotion in the human cutaneous microvasculature during
nonpulsatile cardiopulmonary bypass.

Podgoreanu MV, Stout RG, El-Moalem HE, Silverman DG.

Division of Cardiothoracic Anesthesia and Critical Care Medicine, Duke
University Medical Center, Durham, North Carolina 27710, USA.
podgo001@mc.duke.edu

BACKGROUND: The origin, control mechanisms, and functional significance of
oscillations in microvascular flow are incompletely understood. Although the
traditional belief has been that only low-frequency oscillations (0.04-0.10 Hz)
can originate at the microvascular level, recent evidence in healthy volunteers
has suggested that high-frequency oscillations (> 0.10 Hz) also may have a
microvascular origin (as opposed to being mechanically transmitted
respiratory-induced variations in stroke volume). The current study determined
if such oscillations would emerge in the absence of cardiac and respiratory
activity during nonpulsatile cardiopulmonary bypass (NP-CPB). METHODS: Forehead
and finger laser Doppler flow, arterial pressure, and core temperature were
simultaneously recorded in eight patients during NP-CPB. Analyses included time-
domain indices, frequency-domain indices (auto power spectral density), and a
measure of regularity (approximate entropy) for standardized time segments.
RESULTS: Nonpulsatile cardiopulmonary bypass was associated with the emergence
of rhythmical oscillations in laser Doppler flow, with characteristic
frequencies for the forehead (0.13 +/- 0.03 Hz) and finger (0.07 +/- 0.02 Hz).
Forehead vasomotion became progressively synchronized, with a gain in
high-frequency spectral power from 17.5 (minute 1) to 89.1 (minute 40)
normalized units, and a decrease in approximate entropy from 1.2 (before NP-CPB)
to less than 0.5 (minute 40). CONCLUSIONS: The emergence of forehead
microvascular oscillations at greater than 0.10 Hz (characteristic of
parasympathetic frequency response), in the absence of cardiac and respiratory
variability, demonstrates their peripheral origin and provides insights into
parasympathetic vasoregulatory mechanisms. The progressive synchronization of
forehead vasomotion during NP-CPB, suggestive of increased coupling among
microvascular biologic oscillators, may represent a microcirculatory homeostatic
response to systemic depulsation, with potential implications for end-organ
perfusion.