Coronary Artery Bypass Surgery in Patients with End Stage Renal Disease: Overall Outcome in Single Centre Experience

Background: Coronary artery bypass surgery and its entire perioperative management is demanding in patients with end stage renal disease (ESRD). Methods: We included data from all patients on hemodialysis who underwent coronary artery bypass grafting (CABG) between ovember 1 st, 2003 and November 1 S\ 2006 at Sheikh Zayed hospital and Federal postgraduate medical institute, Lahore, Pakistan. Results: During the study period 41 patients with end stage renal disease underwent coronary artery bypass grafting at the Sheikh Zayed hospital and Federal postgraduate medical institute, Lahore. Among these patients, we recorded a peri operative mortality of 19.51%. Six months survival rate was 75.60 % among study group patients. The incidence of peripheral artery disease is reported significantly higher in the dialysis dependent patients. Uremic patients showed significantly lower hemoglobin serum levels «IOmgldl) at the time of admission. These patients received significantly higher numbers of blood transfusions (~), fresh frozen plasmas (FFP's) when needed. Conclusion: Our preliminary study indicates that coronary artery bypass surgery can be performed with acceptable midterm results when the specific requirements of this patient group are taken into account.

suffering from diabetes or peripheral artery disease'.Most coronary operations are performed using either the extracorporeal circulation or off-pump technique (OPCAB).Factors associated with the former technique such as deviations in fluid balance and serum electrolyte levels hemodilution and disturbances of the coagulatory system require adjusted perioperative management of these patients.Postoperatively, they are prone to complications including septicemia, mediastinitis and prolonged bleeding.The increased incidence of postoperative bleeding may be explained by a disturbance of platelet function caused by uremia".
Cardiovascular disease is the commonest cause of death in end stage renal disease (ESRD) patients, exceeding in rate that of the general population I.In addition, cardiovascular complications are a leading cause of morbidity among ESRD patients.There is increasing emphasis on the treatment of cardiovascular disease in ESRD patients and, on the prevention of cardio ascular disease in patients with renal insufficienc .
Coronary artery disease and end stage renal disease has significant correlation I,. remia is a complex syndrome that influences all the ardiac structures -the pericardium, the myocardium, the endocardium and the coronary system.Most important manifestations of this complex of symptoms, which is also called "uremic heart disease", are hypertensive heart disease and coronary artery disease" When dialysis parients suffer from coronary artery disease, they often ha e severe, diffuse, sometimes even circular, calcifications of the coronary arteries, reaching into the periphery of the vessels.This is probably a result of uremia-associated disturbances of the calcium and phosphate metabolism.In this context, autonomous parathormone (PTH) release with consequent elevation of calcium and phosphate serum levels seems to be important.Besides this, typical comorbidities such as arterial hypertension, peripheral artery disease, hyperiipoproteinemia, renal anemia and disturbances of the carbohydrate metabolism playa significant role [3].As a consequence, it is not surprising that cardiovascular diseases are the primary cause of death in patients requiring chronic hemodialysis.
However, chronic and especially terminal renal insufficiency is also an important risk factor for increased mortality and morbidity after cardiac operations.Only 0.5-1.5% of patients who undergo coronary operations are uremic.Their peri operative mortality, however, is between

Patients and methods
In our study we analyzed data from all patients who are on regular hemodialysis and who underwent coronary artery bypass grafting between ovember l ", 2003 and ovember 1S\ 2006 at the Sheikh Zayed hospital and Federal postgraduate medical institute, Lahore, Pakistan.This is a randomized prospective trial and the data were collected prospectively from patient admitted in our unit or referred to us from other cardiac centers because of their co-existing ESRD, during above mentioned 3 years study period.
As basic data we analyzed all the factors listed in tables 1.Primary inclusion criteria for these ESRD patients with co-existing coronary artery disease is having a history of angina or profound hypotension during hemodialysis.Patients who underwent additional valve operations, who has a history of previous coronary artery surgery and who has a successful renal transplantation were excluded from this analysis.
As a routine procedure all patients underwent a preplanned workup regarding ESRD to optimize the patient's condition for surgery.This criteria was prospectively planned before the trial with the in olvement of nephrology service and all study group patients went through this same protocol given belo .: I. In hospital admission 5 cia, prior to surgery.
3. Bring the central venous pres ure well below 7mm of Hg on immediate preoperative period.4. Improving the Hemoglobin >10m dl by preoperative packed cell trans ions. 5. Keeping serum creatinine < and serum Potassium (K) ~.5 by having three consecutive preoperative hemodialysis as mentioned above.6. Single dose of Inject-able an omycin Ig once a week and inject-able Amika in i gi 'en after 1 51 preoperative day hemodialysis and repeated same after each hemodialysis postoperatively.Peroperatively rapid sequence intubation is the mode of induction of anesthesia in the e c es. Restrict fluid replacement to blood losses, insensible 10 e. and urine utput.Avoid nephrotoxins ( AID' IY contrast, and arninoglycosides) because even small amounts of residual renal function can be important for dialysis patients.Succsarnethonium is avoided along ith other floride roducing drugs because of their nephrotoxic potential and renal excretion dependence.Coronary operations were rformed using extracorporeal circulation or off-pump zechnique (OPCAB).Until March, 2006 all patients were perated, those with on pump technique were given moderate systemic hypothermia (28 e C using cold blood cardioplegia (modified Bleese's solution) for myocardial rotection.During cardiopulmonary bypass, setup was rimed with 1200 mJ of priming solution consisting 500 mJ f whole blood, 500 mJ of Gelafundine (K free sol.) mixed ith 10000 units of heparine sulfate and 200 mJ of Hartman solution as well we performed hernofiltration to liminate this priming volume aiming CVP around 7 cm of H20.Anticoagulation was established by systemic heparin pplication.This was adjusted by use of the activated .lottingtime (ACT, target range 350-500s).
Like the preoperative protocols we also devised the stoperative care protocols in these specific ESRD atients which is as follows: Blood loss in surgical drains was replaced by whole blood only.aHCO} , Ca + and Mg + is to be given according to blood levels in ICU and in ward.7. lnj.Ceftriexon Na + intravenously given with the interval of 12 hours.8. Patient should not be discharged from hospital in not less than 7 post operative days.Data from study group patients were collected for quantitative parameters as we calculated mean and SD.

Result
During the 3 years of the investigation 41 patients with end stage renal disease dialysis dependence underwent coronary anery bypass grafting at the Sheikh Zayed hospital Federal postgraduate medical institute, Lahore P tan..We analyzed 14 different preoperative parameters as listed in Table I.
Almo t all the patients operated on, received atleast one byp graft, and the long sephanous vein graft was our fir t boice.Internal mammory artery (IMA) graft was not used in most of these patients.It was mostly due to the risk of ~fA spasm due to high inotropic support in early post of period causing earl y graft closure.
As expected, we found a lower survival rate in ESRD patients during the whole follow-up period of six months.Among dialysis dependent patients we recorded a perioperative mortality of 19.51 % (8 patients).Heart failure was e of death in 4 (9.75%) of these 8 patients and the corresponding 6 months survival rates were 75.60 %.One patien required reoperation for sternal wound healing disturb e during the postoperative period.Five (12.19%) of our study group patients developed surgical wound infectio Uremic panents showed a significantly lower hemoglobin serum level at the time of admission which is less than 10m dl, Therefore, these patients received significantly higher n ers of blood transfusions (~), as the average blood 10 drainage tubes during the first 24 postoperative urs differed significantly from the routine patients (dialysis dependent patients 600-1100 mJ).These data is summarized in table 2 thrombosis."Uremia" affects platelet function, fibroblast response to injury, and the immune system, but the "uremic toxin(s)" are controversial".
We identified 41 uremic dialysis dependent patients with multi-vessel coronary artery disease among our entire record of CABG patients operated on between 2003 and 2006.More than three-quarters of these patients suffered from coronary triple-vessel disease, arid in most left ventricular function was already diminished.Perioperative mortality among dialysis patients was 19.51 %.This accords with data given in the literature 2 . 6. 7.Almost all of our dialysis patients received long sephanous vein bypass grafts.As expected, we found a lower 6 months survival rate in ESRD patients during the whole follow-up period.Among ESRD patients, we found a significantly higher number of patients who suffered from additional peripheral artery disease.As expected, we found renal anemia in our ESRD patients on admission.Their serum hemoglobin levels were significantly lower, resulting higher number of blood transfusions perooperatively.
Recently Hampl et al 8 have published results which underline the importance of blood substituation in dialysis dependent patients.They found that normalization of serum hemoglobin levels leads to improved cardiac output index in dialysis dependent patients.Peroperative bleeding along with higher volume of surgical drainage probably re ulted from extracorporeal circulation as well as from a disrurbance of platelet dysfunction caused by uremia itseW.In ESRD patient coronary surgery and the entire perioperative management is demanding.However, coronary artery bypass surgery can be performed with ac eptable midterm results when the specific requirements of this patient group are taken into account.
Coronary Artery Bypass Surgery in Patients with End Stage Renal Disease intravenous fluids are restricted to IL / 24hours to keep the patient in -ive balance.Continuous non-invasive cardiac output monitoring to maintain the balance between inotropic supports and fluid balance.Intra-aortic balloon pump (IABP) use when needed.A H AQVI Z PARVEZ F A CHAUDHARY et al 5. Hemodialysis on 2 nd post operative day in lCU and on 4th post-operative day in main dialysis centre to keep the postoperative creatinine ~6 mgldl, serum K+ ~5.5 and CVP ~IO. 6.

Table I .
. Preoperative data of C disease.

Table 2
However, a new study by researchers from the University of California, San Francisco, and Harvard's Schools of Medicine and Public Health on 640 ESRD patients during 1994-1995 of ESRD patients suffering from multi-vessel coronary artery disease suggests that CABG is probably superior to medication alone or coronary angioplasty.As cardiovascular disease is the primary cause of death in patient requiring hemodialysis.Hypertensive heart disease, coronary artery disease and valve disorders (Ire the main pathologies in this patient group.Coronary artery disease in dialysis patients is characterized by severe peripheral and sometimes circumferential calcification of the coronary yes el .Since CABG shows better results than PTCA and stem implantation in dialysis dependent patients, coronary urgery eems to be an important therapeutic option':".Ho vever, dialysis patients suffer higher postoperative mortality and morbidity than other surgical coronary patient .The overall mortality rate for ESRD patients undergoing surgery is 4-20%.The rate is increased 5-fold if surgery is emergent.Anecdotal data suggests a higher mortality in patients with near ESRD v patients with ESRD on chronic dialysis.Major causes of peri-operative Morbidity of ESRD patients is very high (up to 50%), presun.ablydue to volume shifts, acidlbase control, hyperand hypokalemia, and drug toxicity.ESRD patients tend to have longer time on pressors and mechanical ventilation, more IC days, and longer hospital length of stay.Patients with only mild renal insufficiency have increased bleeding risk, need for blood transfusions, lCU stays, and hospital length of stay'.Common causes of morbidity include