Download History :

Cardiac Surgery and Sickle Cell Disease
Khaled E. Al-Ebrahim FRCSC
Department of surgery,Faculty of Medicine
King AbdulAziz University,Jeddah,Saudi Arabia
Please send correspondence to Dr khaled Al _Ebrahim ,department of surgery, king
abdulaziz university hospital ,p o box 80215 Jeddah 21589
[email protected]
TEL 02-6401000 FAX 02-6408347
ABSTRACT
Three cases of homozygous sickle cell disease underwent successful open heart surgery
for multivalvular lesions. The description of the surgical technique and the necessary
precautions are described. Exchange transfusion was implemented in all cases.
We reviewed the world literature and analysed specific crucial issues in cardiac
surgical management of those chronically and critically ill patients to avoid or at least
minimize the vaso-occlusive crisis and associated complications.
Key words : sickle cell, cardiac surgery ,valve procedure.
Introduction
Sickle cell disease is one of the commonest genetic disorder world_wide and affecting
about 8% of black people[1] .The prevalence in Saudi Arabia in not studied.
Sickle cell anemia is an inherited disease in which the red blood cells, normally discshaped, become crescent shaped causing small blood clots which give rise to recurrent
painful episodes called "sickle cell pain or vaso- occlusive crises".Complications of
sickle cell disease include recurrent aplastic and hemolytic
anemia , gallstones
,multisystem disease (kidney, liver, lung (,narcotic abuse
,splenic sequestration
syndrome , acute chest syndrome ,erectile dysfunction (as a result of priapis)
,
blindness/visual impairment , neurologic symptoms and stroke , joint destruction ,
infection, including pneumonia, cholecystitis , osteomyelitis , and urinary tract [2,3].
As surgery in general and especially cardiac surgery in homozygous patients is
associated with high morbidity and mortality, special care and certain precautions are
required peri-operatively in their management to minimize the surgical risk.
Patients and Methods
Three patients with sickle cell disease underwent open heart surgery for multivalvular
lesions .The deails are as follows.
CASE #1
18 years old chadian male patient known case of sickle cell disease(80% sickling by
hemoglobin electropheresis) ,renal impairment and
rheumatic heart disease was
admitted with abdominal pain, dyspnoea, recurrent fever and chills.On examination
his temperature was 38.5, heart rate 110,normal sinus rhythm , blood pressure
100/60.Auscultation revealed visible laterally displaced apex beat ,pansystolic mitral
murmer and early diastolic aortic murmer. His Hemoglobin was 7.5 g/dl, white cell
count was 19 000k/uL , urea 34mmol,creatinin 369umol ,total bilirubin was 130umol
,indirect bilirubin 90umol. He was admitted to the intensive care unit where
ecchocardiography showed dilated cardiac
chambers
,severe mitral and aortic
regurgitatin , moderate pulmonary regurgitation and pulmonary hpertension..Ejection
fraction was only 30%. Blood cultures were sent and the patient started on empiric
antibiotics ,ceftriaxon , erythromicine and ampicillin . The following day, the patient
developed
convulsions
and
he was intubated and mechanically ventilated
.
Computerised tomography scan of the brain was showed suspicious hypodensity in the
right periventriculer white matter region. The patient improved gradually and
extubated . The cultures grew staphylococcus epidermidis (coagulase negative) and he
received six weeks of intravenous antibiotics. He was discharged and readmitted for
valve replacement . Cardias Surgery was done where metallic aortic and mitral valves
(ATS MEDICAL ) were inserted . All Perioperative sickle cell precautions were
undertaken . Postoperative course was smooth .The patient was started on
anticoagulation ,mobilized and discharged home well.
Case #2 :
28 years old male patient ,originally from south Saudi Arabia, known case of sickle cell
disease , rheumatic heart disease, severe mitral and aortic regurgitation. He was
admitted for recurrent attack of shortness of breath on moderate exertion .
Cardiac examination revealed muffeled first heart sound , normal second heart sound ,
pansystolic murmer over the apex radiating to the axilla and early diastolic murmer
over aortic area . No lower limb edema .
His hemoglobin was 7.5gram% . Urea and
electrolyte were normal. Elctrocardiogram showed normal sinus rhythm, left
ventricular dilatation.
Ecchocardiography revealed severe aortic insufficiency , moderate to severe mitral
insufficiency , left ventricular
dysfunction , moderate to severe
pulmonary
hypertention , ejection fraction 60%.
The patient underwent aortic and mitral valve replacement using St Jude Medical
Biocor valves (aortic valve size 21 and mitral valve size 27). The patient had smooth
intra and postoperative course .Cardiac rehabilitation and temporary anticoagulation
were started. Postoperative ecchocrdiography showed status post mitral and aortic
valve replacement ,both valves were functioning well, no paravalvuler leak or
dihescence with mild to moderate left ventricular dysfunction , ejection fraction
50%.Patient was discharged home in good condition with clinic followup. He has been
followed for more than one year with steady improvement.
Case #3
14 years old Sudanese female patient known case of sickle cell disease (more than
80%by electrohemopharesis ), rheumatic heart disease mainly severe mitral and
tricuspid regurgitation , pulmonary HTN , old treated TB.
She presented to the emergency room with bilateral lower limb edema for 3 day
associated with shortness of breath at rest and orthopnea .
On examination, the patient was jaundiced , multiple cervical lymph nodes, her jugular
venous pressure was 7-8 cm , hyperdynamic circulation,regular pulse, normal first
heart sound , loud secod heart sound , pansystolic murmer at mitral and tricuspid area,
Abdominal examination revealed hepatomegaly
and ascitis. She had also bilateral
lower limb edema .
She was started on diuretics and digoxin . During hospitalization she went into fast
atrial fibrillation which was controlled with amiodaron .
The patient underwent mitral and aortic valve repair using annuloplasty flexable
rings(size 30 for the mitral and 32 for the tricuspid) . Postoperative course was smooth
and eventually she was discharged home in good condition .
METHODS:
General anesthesia was induced using ethomidate, fentanyl, midazolam and
pancuronium
and
was
maintained
oxide.Cardiopulmonary bypass was
using
isoflurane
,oxygen
and
nitrous
constructed using membrane oxygenator,
cardiotomy reservoir , regular and haemofilters, and tubing set .The circuit was primed
using ringers lactate ,5% dextrose ,8.4% sodium bicarbonate and 1 unit of blood.
Heparinisation was achieved by 300 units/kg. Normothermic bypass was coducted
using aortic and bicaval cannulae and cardiac arrest was achieved with hypothermic
blood cardioplegia. All patients underwent about 30%exchange transfusion
and
continuous haemofiltration during cardiopulmonary bypass. The haemoglobin was
maintained between 6-8.5 g/dl with a hematochrit between 18-28%.Th mitral valve was
approached through the interatrial groove.All three patients had different valve
procedure. The first case received two mechanical valves using ATS MEDICAL,hoping
for its proven low thrombogenicity, as both valves were destroyed by the endocarditis
process and to avoid hypercalcification of bioprosthetic valves which is usually
associated with renal failure patients .The second patient received two tissue valves to
avoid the controversial issue of prosthetic valve associated hemolysis [6]. In the third
patient ,fortunately both mitral and aortic valves were repaired using annuloplasty
rings. All three patients were weaned off cardiopulmonary bypass without difficulty .
Discussion
Sickle cell anemia affects millions throughout the world. It is particularly common
among people whose ancestors come from sub-Saharan Africa; South America, Cuba,
Central America, Saudi Arabia; India; Turkey, Greece, and Italy.
Hemoglobin (HbS) results from single base mutation in beta chain of haemoglobin ,
adenine base replaced by thymine so glutamic acid is replaced by valine. Sickling test
and hemoglobin electrophoresis help in diagnosis and
differentiates individuals who
are homozygous from those who are heterozygous. A homozygous patient will have
hemoglobin SS (HbSS, 80-90%), hemoglobin F (HbF, 2-20%), and hemoglobin A2
(HbA2, 2-4%). A carrier patient will have HbSS (35-40%) and hemoglobin A (HbA, 6065%). The test is not accurate in a patient who has recently received blood
transfusions[3].
Clinically, common symptoms
include
paleness,
yelloweyes/skin,
fatigue,
breathlessness , rapid heart rate ,delayed growth and puberty . Sickling may be
induced by hypoxia ,hypothermia ,cidosis ,vascular stasis or hypovolemia.
The purpose of therapy is to manage and control symptoms and to try to limit the
frequency of vaso-occlusive crises.
During a sickle crisis, certain therapies may be necessary. Painful episodes are
treated with analgesics and adequate liquid intake.
Hydroxyurea (Hydrea) was found to help some patients by reducing the frequency of
painful crises and episodes of acute chest syndrome and decreasing the need for blood
transfusions. Antibiotics and vaccines are given to prevent bacterial infections, which
are common in those children.
The risk of an intraoperatively crisis due to sickle cell disease is a major consideration
in cardiovascular surgery. It is will documented in the medical literature that low
oxygen tension and acidosis can induce sickling in the red cell and in those patients the
cardiopulmonary bypass, as an artificial circulation wholly controlled by the
perfusionist , may trigger a crisis of profound magnitude .
As regard to cardiopulmonary bypass several precautions and issues have to be
addressed and analyzed . These included
cardiopulmonary bypass temperature,
whether to cool or warm, also cardioplegia temperature , the need for partial exchange
transfusion and
continuous haemofiltration. It is generally worldwide agreed that
avoidance of acidosis , maintenance of cardiopulmonary bypass adequate blood flow
,oxygen tension and close monitoring of laboratory results are essential basics in the
management of sickle patients[4-7]. These issues have to be very well understood by the
perfusionist , anaesthesiologist and the surgical team as violation may increase the
surgical risk and jeoperdise patient life. Contiuous on line arterial oxygen tension , acid
base balance and temperature are essential. Intra and postoperative control of the
haemodynamics, regular follow up of haematocrit , keeping it between 20 and 30%,
electrolytes , blood gases, avoidance or minimizing postoperative pain are important in
those patients
Although ,it is preferable to avoid hypothermia which will cause vasoconstriction in
those patients ,still a number of studies, case reports, have employed mild to moderate
cooling without adverse effect[7,8]. Reviewing the literature and from our cases we
found that normothermic bypass , allowing the temperature to drift and using only cold
cardioplegia, at four degrees centigrade, is the safest especially when operating on high
risk and large number of cases[4-6,9,10,14,15]. Warm blood cardioplegia ,with its high
potassium , may have deleterious effect on patients with impaired renal function
Pre or intraoperative partial exchange transfusion have been recommended by many
authors and implemented in the majority of cardiac patients to reduce the percentage of
Hb SS[6,7,9,10] . At least 30 % of the circulating plasma volume is sequestered to
improve the quality of the perfusate, increase oxygen delivery and to decrease the risk
of a sickle cell crisis during bypass . In few case reports ,exchange transfusion was not
implemented [5,8]. In the series of Metras et al.,most of the cases ,13 patients, were
sickle cell trait . In our cases , exchange transfusion was done once intra operatively
,after cannulating and before going on bypass . The perfusionist drains about 500 to
1000ml of blood from the venous reservoir ,depending on the patient body weight , and
replaced with 1 to 2 units of packed red blood cells .
Hemofiltration will increase hematocrit, platelets and clotting factors, help potassium
removal, reduce complement activation, reduce extracellular water and help in avoiding
acidosis. Several papers showed the favorable but sometimes variable effect of
haemofiltration especially in the pediatric patients[6,7,11-13].
Valve repair remains the procedure of choice to avoid prosthetic valve related
complications especially hemolysis,anti-coagulation and infection[5-8,14].
In our review of the literature , several authors did not show any preference of tissue
valves over mechanical valves[4,5,7,8,15]. Others showed that mechanical valves should
be avoided in sicklers to minimize the risk of hemolysis which may induce crisis[6]. In
our cases ,we used three different valve procedures . Given the short life expectancy of
those patients , the risk of mechanical valve hemolysis , tissue valve hypercalcification
and risk of reoperation , we prefer , in nonrepairable valves, use of mechanical valves
for patients less than 30 years and elder patients may receive biological valves.
Postoperative pain management is helped by receiving multiple analgesia. Prophylactic
antibiotic therapy is important in those patients to minimize the risk of infection.
These three cases performed by the author received different valve procedures which
emphesises the tolerance of those patients as long as the body environment during and
after surgery are suitable and not triggering vasospasm . Four previous other sickle cell
trait patients underwent also valvular procedures by the author in another institution
and did not face any problems as those trait cases are not as critical as the homozygous.
The world literature is deficient and has no major scientific contribution to help this
sector of cardiac patients , except of sporadic case reports , most of it more than a
decade ago.
References
[1] Heller P, Best WR, Nelson RB, Becktel J. Clinical implication of sickle cell trait
and G6PD in hospitalized black male patients. N Engl J Med 1979;300:1001-5.
[2] Ned JV.Sickle cell disease :a worldwide problem. In Abrahamson H, Bertles JF,
Wether DL, eds. Sickle Cell Disease: diagnosis, management, education and
research.St Louis:Mosby1973.
[3] WintrobeMM. Clinical hematology,Philadelphia:Lea&Febiger,1993:1064.
[4] Wenham PW, Scott GI, Wisheart JD. Red blood cell survival after aortic valve
replacement with Bjork-Shiley prosthesis in presence of sickle cell trait. Br Heart J
1978;40:703-4.
[5]
Metras
P,
Chauvet
J.
Open
heart
surgery
in
sickle
cell
haemoglobinopathy;report of 15 cases. Thorax 1982;37:486-91.
[6] Balasundaram S,Duran CG,Al-halees Z,Kassay M.Cardiopulmonary bypass in
sickle cell anemia ,Report of five cases.JCardiovascSurg(Torino)1991;32:271-40
[7] Sutton SW,Hunley EK,Duncan MA,RodreguesR,Meyers T. Sickle Cell Disease
and Aortic Valve Replacement. Texas Heart Inst J 1999;26:283-8.
[8]Frimbong-Boateng
K
,
Amoah
AGB,
Barwasser
H-M,
Kallen
C.
Cardiopulmonary bypass in sickle cell anaemia without exchange transfusion.
European Journal of Cardio-Thoracic Surgery1998;14(5):527-9.
[9] Black HA, Dearing JP. Exchange transfusion prior to cardiopulmonary bypass
in sickle cell anemia. J Extra-corp Technol 1980;12:82-5.
[10] Chun PKC, Flannery EP, Bowen TE. Open heart surgery in patients with
hematologic disorders. Am Heart J 1983;105:835-42.
[11]
Hata
M,Raman
JS,
Bellomo
R,
BuxtonBF,
ShionoM,
Sezai
Y.Hemofiltration during cardiopulmonary bypass for high risk adult cardiac surgery.
Science Links Japan 2002;44:53-60.
[12] Brancaccio G, Villa E, Girolami E. Inflammatory cytokines in pediatric
surgery
and variable effect of the hemifiltration process.Perfusion2005;22:263-8.
[13] Sexana P, SexanaN, Sharma R. Efficacy of haemofiltration
during
cardiopulmonary bypass in pediatric open heart surgery.2001;17(2):73-6.
[14] Pagani FD, Polito RJ, Bolling SF. Mitral valve reconstruction in sickle cell disease
.Ann Thorac Surg 1996;61:1841-3.
[15] Craenen J, Kilman J, Hosier DM, Weinberger M. Mitral valve replacement in a
child with sickle cell anemia. J Thorac Cardiovasc Surg 1972;63:797-9.
Date 12 June 2008
Dr. khaled Al _Ebrahim
To
Tracking No. OC 80092
[Please quote this tracking # on all your
correspondence]
Cardiac Surgery and Sickle Cell Disease
Title
The comments raised by reviewers must be addressed in the revised manuscript
Disagree
(must give
Summary
Agree
reasons)
Problems during cardiopulmonary bypass
yes
Technique of exchange transfusion
yes
Cardioplegia temperature ,
yes
1
3
4
PLEASE NOTE: REVISION SUBMISSION WITHOUT RETURNING THIS
FORM WILL NOT BE PROCESSED
Reasons for Disagreement: