J Thorac Cardiovasc Surg. 2003 Sep;126(3):826-31.  

Surgical repair of acute type A aortic dissection: Continuous pulmonary
perfusion during retrograde cerebral perfusion prevents lung injury in a pilot
study.

De Santo LS, Romano G, Amarelli C, Onorati F, Torella M, Renzulli A, Galdieri N,
Cotrufo M.

OBJECTIVE: Postoperative respiratory failure is a frequent and serious
complication in patients with type A acute aortic dissection operated on with
deep systemic hypothermia. Interaction between neutrophils and pulmonary
endothelium along with ischemic insult and reperfusion are the major
determinants of lung injury. The aim of this prospective study was to evaluate
the effect of continuous pulmonary perfusion during retrograde cerebral
perfusion on lung function. METHODS: Twenty-two patients referred for acute type
A aortic dissection, who were free from preoperative respiratory dysfunction,
were assigned prospectively and alternately to one of 2 treatment groups.
Pulmonary perfusion was performed during retrograde cerebral perfusion in group
B (11 patients), whereas the conventional Ueda technique was applied in group A
(11 patients). Lung function was evaluated on the basis of intubation time,
scoring of chest radiographs at 12 hours after cardiopulmonary bypass, and
Pao(2)/fraction of inspired oxygen ratio assessed from immediately before the
operation to 72 hours after termination of cardiopulmonary bypass. RESULTS:
Study groups were homogeneous for age, sex, interval between symptom onset and
surgical operation, previous aortic surgery, preoperative ejection fraction and
pulmonary gas exchange function, extent of aortic repair, and concomitant
procedures. Cardiopulmonary bypass time, length of retrograde cerebral
perfusion, operation time, need for blood substitutes, and surgical revision for
bleeding did not differ between treatment groups. Postoperative Pao(2)/fraction
of inspired oxygen ratios were higher in group B than in group A, and the
difference remained statistically significant throughout the study period. The
incidence of prolonged ventilator support (>72 hours) and the severity of the
radiographic pulmonary infiltrate score were lower in the perfused group (18.2%
vs 72.7% [P =.015] and 0.81 +/- 0.75 vs 1.8 +/- 0.78 [P =.028], respectively).
CONCLUSIONS: Continuous pulmonary perfusion provided a better preservation of
lung function in patients operated on with deep systemic hypothermia.

J Thorac Cardiovasc Surg. 2003 Sep;126(3):680-7.  

Vacuum-assisted venous return reduces blood usage.

Banbury MK, White JA, Blackstone EH, Cosgrove DM 3rd.

OBJECTIVE: To determine whether vacuum-assisted venous return has clinical
advantages over conventional gravity drainage apart from allowing the use of
smaller cannulas and shorter tubing. METHODS: A total of 150 valve operations
were performed at our institution between February and July 1999 using
vacuum-assisted venous return with small venous cannulas connected to short
tubing. These were compared with (1) 83 valve operations performed between April
1997 and January 1998 using the initial version of vacuum-assisted venous
return, and (2) 124 valve operations performed between January and April of 1997
using conventional gravity drainage. Priming volume, hematocrit value, red blood
cell usage, and total blood product usage were compared multivariably. These
comparisons were covariate and propensity adjusted for dissimilarities between
the groups and confirmed by propensity-matched pairs analysis. RESULTS: Priming
volume was 1.4 +/- 0.4 L for small-cannula vacuum-assisted venous return, 1.7
+/- 0.4 L for initial vacuum-assisted venous return, and 2.0 +/- 0.4 L for
gravity drainage (P <.0001). Smaller priming resulted in higher hematocrit
values both at the beginning of cardiopulmonary bypass (27% +/- 5% compared with
26% +/- 4% and 25% +/- 4%, respectively, P <.0001) and at the end (30% +/- 4%
compared with 28% +/- 4% and 27% +/- 4%, respectively, P <.0001). Red cell
transfusions were used in 17% of the patients having small-cannula
vacuum-assisted venous return, 27% of the initial patients having
vacuum-assisted venous return, and 37% of the patients having gravity drainage
(P =.001); total blood product usage was 19%, 27%, and 39%, respectively (P
=.002). Although ministernotomy also was associated with reduced blood product
usage (P <.004), propensity matching on type of sternotomy confirmed the
association of vacuum-assisted venous return with lowered blood product usage.
CONCLUSIONS: Vacuum-assisted venous return results in (1) higher hematocrit
values during cardiopulmonary bypass and (2) decreased red cell and total blood
product usage.

Crit Care Med. 2003 Sep;31(9):2324-31.  

Noninvasive, near infrared spectroscopic-measured muscle pH and PO2 indicate
tissue perfusion for cardiac surgical patients undergoing cardiopulmonary
bypass.

Soller BR, Idwasi PO, Balaguer J, Levin S, Simsir SA, Vander Salm TJ, Collette
H, Heard SO.

Department of Surgery, University of Massachusetts Medical School, Worcester,
MA, USA.

OBJECTIVE: To determine whether near infrared spectroscopic measurement of
tissue pH and Po2 has sufficient accuracy to assess variation in tissue
perfusion resulting from changes in blood pressure and metabolic demand during
cardiopulmonary bypass. DESIGN: Prospective clinical study. SETTING: Academic
medical center. SUBJECTS: Eighteen elective cardiac surgical patients.
INTERVENTION: Cardiac surgery under cardiopulmonary bypass. MEASUREMENTS AND
MAIN RESULTS: A near infrared spectroscopic fiber optic probe was placed over
the hypothenar eminence. Reference Po2 and pH sensors were inserted in the
abductor digiti minimi (V). Data were collected every 30 secs during surgery and
for 6 hrs following cardiopulmonary bypass. Calibration equations developed from
one third of the data were used with the remaining data to investigate
sensitivity of the near infrared spectroscopic measurement to physiologic
changes resulting from cardiopulmonary bypass. Near infrared spectroscopic and
reference pH and Po2 measurements were compared for each subject using standard
error of prediction. Near infrared spectroscopic pH and Po2 at baseline were
compared with values during cardiopulmonary bypass just before rewarming
commenced (hypotensive, hypothermic), after rewarming (hypotensive,
normothermic) just before discontinuation of cardiopulmonary bypass, and at 6
hrs following cardiopulmonary bypass (normotensive, normothermic) using
mixed-model analysis of variance. Near infrared spectroscopic pH and Po2 were
well correlated with the invasive measurement of pH (R2 =.84) and Po2 (R 2 =.66)
with an average standard error of prediction of 0.022 +/- 0.008 pH units and 6
+/- 3 mm Hg, respectively. The average difference between the invasive and near
infrared spectroscopic measurement was near zero for both the pH and Po2
measurements. Near infrared spectroscopic Po2 significantly decreased 50% on
initiation of cardiopulmonary bypass and remained depressed throughout the
bypass and monitored intensive care period. Near infrared spectroscopic pH
decreased significantly during cardiopulmonary bypass, decreased significantly
during rewarming, and remained depressed 6 hrs after cardiopulmonary bypass.
Diabetic patients responded differently than nondiabetic subjects to
cardiopulmonary bypass, with lower muscle pH values (p =.02). CONCLUSIONS: Near
infrared spectroscopic-measured muscle pH and Po2 are sensitive to changes in
tissue perfusion during cardiopulmonary bypass.

Circulation. 2003 Sep 9;108(10 Suppl 1):II278-84.  

Modulation of circulating endothelin-1 and big endothelin by nitric oxide
inhalation following left ventricular assist device implantation.

Wagner FD, Buz S, Knosalla C, Hetzer R, Hocher B.

Deutsches Herzzentrum Berlin, Germany Charite der Humboldt Universitat Berlin,
Berlin, Germany. Wagner@dhzb.de

BACKGROUND: Inhaled nitric oxide (iNO) is an established therapy in the
treatment of pulmonary hypertension and right ventricular dysfunction following
left ventricular assist device implantation. Since it is known that endothelin-1
contributes to pulmonary hypertension, and nitric oxide modulates endothelin-1
synthesis in vitro, we investigated the effects of iNO on circulating
endothelin-1 and big endothelin following left ventricular assist device
implantation. METHODS AND RESULTS: On weaning from cardiopulmonary bypass, 15
consecutive patients with secondary pulmonary hypertension after implantation of
a left ventricular assist device were treated with iNO. Endothelin-1 and big
endothelin plasma levels were measured preoperatively, on cardiopulmonary bypass
prior to iNO, 12, 24, and 48 hour postoperatively, and 72 hour after cessation
of iNO. Endothelin-1 levels were increased preoperatively (1.05+/-0.20 fmol/L),
and were highest on cardiopulmonary bypass (1.65+/-0.27 fmol/L). During iNO
therapy endothelin-1 and big endothelin decreased significantly (endothelin-1:
12 hour 1.24+/-0.18, 24 hour 0.93+/-0.20, and 48 hour 0.81+/-0.14 fmol/L); they
were lowest 72 hour post-iNO (endothelin-1: 0.56+/-0.09 fmol/L). Plasma
endothelin-1 concentrations and iNO dose were inversely correlated (r=-0.657,
P<0.015). A significant correlation was also found between endothelin-1 versus
PA pressures and PVR/SVR ratio, but not with CI and SVR. CONCLUSIONS: Since it
is known that endothelin-1 mediates pulmonary hypertension, we suggest a 2-fold
effect of iNO therapy: firstly, a selective vasodilation of the pulmonary
vasculature; and secondly, iNO mediated modulation of endothelin-1.

Circulation. 2003 Sep 9;108(10 Suppl 1):II191-4.  

Totally endoscopic atrial septal defect repair with robotic assistance.

Argenziano M, Oz MC, Kohmoto T, Morgan J, Dimitui J, Mongero L, Beck J, Smith
CR.

Division of Cardiothoracic Surgery, Columbia University College of Physicians
and Surgeons, New York, NY, USA. ma66@columbia.edu

BACKGROUND: Computer (robotic) enhancement had emerged as a facilitator of
minimally invasive cardiac surgery, and has been used to perform portions of
intracardiac procedures via thoracotomy incisions. This report describes the
next step in this progression-the first U.S. application of robotic technology
for totally endoscopic open heart surgery. METHODS AND RESULTS: Seventeen
patients underwent repair of a secundum-type atrial septal defect (n=12) or
patent foramen ovale (n=5) by a totally endoscopic approach, utilizing the Da
Vinci robotic system. Cardiopulmonary bypass (CPB) was achieved peripherally.
Cardioplegia was administered via the distal port of the arterial cannula after
endo-balloon inflation. Via three port incisions in the right chest,
pericardiotomy, bicaval occlusion, atriotomy, atrial septopexy, and atrial
closure were performed by a surgeon seated at a computer console. A fourth 15-mm
port was utilized for suction and suture passage by a patient-side assistant.
The mean age of the patients was 47 years (range, 22 to 68). Aortic crossclamp
time was 32 minutes (median), and CPB time was 122 minutes. In 16 patients,
transesophageal echocardiography after 30 days confirmed successful repair. In
one patient, a recurrent shunt was identified and repaired on postoperative day
5. Median length of stay (LOS) in the intensive care unit was 20 hours, and
median hospital length of stay was 4 days. CONCLUSIONS: Robotic technology can
be utilized to perform open heart procedures safely and effectively via totally
endoscopic approaches. This technique represents an option for patients seeking
a reliable ASD repair but wishing to avoid sternotomy or thoracotomy.

Eur J Cardiothorac Surg. 2003 Sep;24(3):399-403.  

Circulatory support for fulminant myocarditis: consideration for implantation,
weaning and explantation.

Leprince P, Combes A, Bonnet N, Ouattara A, Luyt CE, Theodore P, Leger P, Pavie
A.

Service de Chirurgie Thoracique et Cardiovasculaire, Groupe Pitie-Salpetriere,
Institut de Cardiologie, 47-83 Boulevard de l'hopital, 75013, Paris, France

OBJECTIVE: Fulminant myocarditis (FM) is an uncommon but life-threatening
condition for which a mechanical circulatory support (MCS) device can be
life-saving. However, device selection, weaning and explantation procedures
remain poorly defined. METHODS: Four patients were bridged to recovery using the
Thoratec((R)) biventricular support device. All four were in a state of
cardiogenic shock with rapid deterioration of their clinical status despite
increasing doses of inotropes. Three patients required mechanical respiratory
support, three were anuric and one was dialyzed. Echocardiography showed a mean
ejection fraction of 12+/-8%. RESULTS: Each Thoratec implantation was performed
on cardiopulmonary bypass with a beating heart. Three patients underwent
biventricular cannulation. The fourth patient underwent left ventricular and
right atrial cannulation. All patients manifested evidence of moderate to severe
end organ dysfunction after device implantation. However, by explantation, end
organ function had recovered in all patients. After a mean duration of 17+/-10
days, all the patients showed evidence of myocardial recovery. Recovery was
confirmed on echocardiography which showed opening of the aortic valve and
contraction of both ventricles. The weaning process was performed in 2-5 days by
setting the device in a fixed mode and increasing the rate. Device explantation
was uneventful in the four patients. At the 6 months echocardiography follow-up,
all had normal systolic function. CONCLUSION: In patients with FM, biventricular
support allows full circulatory support and unloads both ventricles until
recovery occurs. In this set of patients, weaning and removal procedures are
straight-forward. These results suggest an aggressive stance toward implantation
of MCS in patients with FM.

Ann Thorac Surg. 2003 Sep;76(3):784-91.  

The association of lowest hematocrit during cardiopulmonary bypass with acute
renal injury after coronary artery bypass surgery.

Swaminathan M, Phillips-Bute BG, Conlon PJ, Smith PK, Newman MF, Stafford-Smith
M.

Department of Anesthesiology, Duke University Medical Center, Durham, North
Carolina, USA

Acute renal injury is a common serious complication of cardiac surgery. Moderate
hemodilution is thought to reduce the risk of kidney injury but the current
practice of extreme hemodilution (target hematocrit 22% to 24%) during
cardiopulmonary bypass (CPB) has been linked to adverse outcomes after cardiac
surgery. Therefore we tested the hypothesis that lowest hematocrit during CPB is
independently associated with acute renal injury after cardiac
surgery.Demographic, perioperative, and laboratory data were gathered for 1,404
primary elective coronary bypass surgery patients. Preoperative and daily
postoperative creatinine values were measured until hospital discharge per
institutional protocol. Stepwise multivariable linear regression analysis was
performed to determine whether lowest hematocrit during CPB was independently
associated with peak fractional change in creatinine (defined as the difference
between the preoperative and peak postoperative creatinine represented as a
percentage of the preoperative value). A p value of less than 0.05 was
considered significant.Multivariable analyses including preoperative hematocrit
and other perioperative variables revealed that lowest hematocrit during CPB
demonstrated a significant interaction with body weight and was highly
associated with peak fractional change in serum creatinine (parameter estimate
[PE] = 4.5; p = 0.008) and also with highest postoperative creatinine value (PE
= 0.06; p = 0.004). Although other renal risk factors were significant
covariates in both models, TM50 (an index of hypotension during CPB) was notably
absent.These results add to concerns that current CPB management guidelines
accepting extreme hemodilution may contribute to postoperative acute renal and
other organ injury after cardiac surgery.

 Ann Thorac Surg. 2003 Sep;76(3):744-8.  

Quality of intraoperative autologous blood withdrawal used for retransfusion
after cardiopulmonary bypass.

Flom-Halvorsen HI, Ovrum E, Oystese R, Brosstad F.

Oslo Heart Center, Research Institute for Internal Medicine, University of Oslo,
Oslo, Norway

Intraoperative autologous blood withdrawal protects the pooled blood from the
deleterious effects of cardiopulmonary bypass. Following reinfusion after
cardiopulmonary bypass, the fresh autologous blood contributes to less
coagulation abnormalities and reduces postoperative bleeding and the need for
allogeneic blood products. However, few data have been available concerning the
quality and potential activation of fresh blood stored at room temperature in
the operating room.Forty coronary artery bypass grafting patients undergoing a
consistent intraoperative and postoperative autotransfusion protocol had a
median of 1,000 mL of autologous blood withdrawn before cardiopulmonary bypass.
After heparinization the blood was drained from the venous catheter via venous
cannula into standard blood bags and stored in the operating room until
termination of cardiopulmonary bypass. Samples for hemostatic and inflammatory
markers were taken from the pooled blood immediately before it was returned to
the patient.There was some activation of platelets in the stored autologous
blood, as measured by an increase of beta-thromboglobulin. Indications of
thrombin formation, as assessed by plasma levels of thrombin-antithrombin
complex and prothrombin fragment 1.2 were not seen, and there was no
fibrinolytic activity. The red blood cells remained intact, indicated by the
absence of plasma free hemoglobin. As for the inflammatory response, the levels
of the terminal complement complex remained stable, and the cytokines tumor
necrosis factor-alpha and interleukin 6 levels were not increased during
storage. The complement activation products increased minimally, but remained
within normal ranges.Except for slight activation of platelets, there was no
indication of coagulation, hemolysis, fibrinolysis, or immunologic activity in
the autologous blood after approximately 1 hour of operating room storage. The
autologous blood was preserved in a condition of high quality, and retransfusion
after cardiopulmonary bypass represents an uncomplicated and almost costless
procedure for blood conservation.

Br J Anaesth. 2003 Sep;91(3):424-6.  

Genotype and interleukin-10 responses after cardiopulmonary bypass.

Galley HF, Lowe PR, Carmichael RL, Webster NR.

Academic Unit of Anaesthesia and Intensive Care, Institute of Medical Sciences,
University of Aberdeen, Aberdeen AB25 2ZD, Scotland, UK. h.f.galley@abdn.ac.uk

BACKGROUND: The pro- and anti-inflammatory cytokine balance has been implicated
in outcome from inflammatory conditions, and cardiopulmonary bypass is
associated with a marked inflammatory response. Interleukin-10 (IL-10) is an
anti-inflammatory cytokine and levels have been shown to be highest in those
patients who develop sepsis after trauma or surgery. IL-10 levels vary between
individuals and genotype may dictate the IL-10 response. We therefore
investigated IL-10 genotype, circulating IL-10 concentrations and outcome in
terms of organ dysfunction 24 h after cardiopulmonary bypass. METHODS: Blood
samples were obtained from 150 patients before, and 3, and 24 h after
cardiopulmonary bypass. IL-10 was measured by enzyme immunoassay. The single
nucleotide polymorphism at -1082 base pairs was detected by restriction fragment
length polymorphism analysis. Post-bypass organ system dysfunction was defined
prospectively. RESULTS: IL-10 concentrations were increased 3 h after bypass
(P<0.0001) and were still increased at 24 h (P<0.0001). Homozygosity for the G
allele was associated with lower median (range) maximal IL-10 levels at 3 h (44
(13-136) pg ml(-1)) compared with the A allele (118 (39-472) pg ml(-1);
P=0.042). Those patients who developed at least one organ dysfunction (n=33) had
higher IL-10 levels 3 h after surgery (242 (18-694) pg ml(-1)) compared with
those without organ dysfunction (77 (7-586) pg ml(-1); P=0.001, n=117).
CONCLUSIONS: The G allele of the -1082 base pair single nucleotide polymorphism
in the IL-10 gene is associated with lower IL-10 release after cardiopulmonary
bypass. High levels of IL-10 secretion are associated with organ dysfunction 24
h after surgery.