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MITRAL VALVE REPLACEMENT INA CASE OF CHRONIC RENAL FAILURE DUE TO LUPUS NEPHRITIS

PRANAVA SINHA*, PRAGNESH JOSHI*, SANJEEV JADHAV*,CHIRAG DOSHI*, KANAK NAGLE**, JAYANT N KARBHASE***
*Senior Registrar; **Associate Professor; ***Professor and Head, Department of CVTS, BYL Nair Ch. Hospital, Mumbai.

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A 32-year-old male, diagnosed case of lupus nephritis with chronic renal failure and hypertension presented with progressive dyspnoea on exertion (class II - class III over last two years). On evaluation he was found to have rheumatic heart disease with severe mitral incompetence, with fibrosis and thickening of the mitral leaflets and left ventricular dysfunction. He underwent mitral valve replacement with ball and socket type Starr Edward’s mitral prosthesis. An ultrafiltration was used in the bypass circuit to filter the crystalloid fluid prime. The authors here present the technique used in the cardiopulmonary bypass and review of available literature.

CASE REPORT

A 32-year-old male, suffering from chronic renal failure due to the rare cause of lupus nephritis and renovascular hypertension, presented with progressive dyspnoea of grade II/III since last two years. The patient was on phenytoin prophylaxis following intracerebral bleed 3 years back, however had no neurological deficit. On evaluation the patient was found to have rheumatic heart disease with severe mitral incompetence. The left ventricle was dilated with LVIDs of 44 mm and LVIDd of 57 mm. The LVEF was 45%.

Laboratory parameters were : Serum creatinine - 4.3 mg%, BUN - 45 mg%, Hb - 10.1 gm%, Total proteins - 5.8 gm% and albumin - 2.7 gm%. Coagulation studies were normal.

The patient was given standard endotracheal anaesthesia with induction with sodium pentothal, atracurium and isoflurane and was maintained on nitrous oxide and atracurium.

Midsternotomy was done. Cardiopulmonary bypass was established with standard bicaval cannulation. Membrane oxygenator was primed with 1500 ml of Ringer’s lactate with mannitol added for maintaining adequate GFR on cardiopulmonary bypass. An adult ultrafiltration set was attached to the bypass circuit. The patient was cooled to 32 degrees Celsius and the pump flow rate was 2.2 L/min/metre sq. The perfusion pressure was maintained at around 60 mm Hg to maintain adequate renal perfusion. Antegrade cold crystalloid hyperkalaemic cardioplegia was used for myocardial preservation. Adenosine was added to cardioplegia. During cardioplegia administration an external suction through a small right atriotomy was used to suck out all the effluent of the coronary sinus to avoid systemic hyperkalaemia. Mitral valve replacement was done with a Starr Edwards 2M prosthesis. The cross clamp time was 30 minutes. While weaning the patient off bypass, ultrafiltration was used to filter 1200 ml of crystalloids to avoid any fluid overload. The serum potassium during the entire operative procedure remained between 4 and 4.5 meq/dl. Intraoperative urine output was 300 ml. The patient was started on Dopamine infusion at renal dose which was continued postoperatively for 24 hrs. The intraoperative blood loss was 480 ml. We used cefazolin and amoxycillin + clavulinic acid in the postoperative period. The patient was extubated after five hrs. Patient did not have metabolic acidosis, hyperkalaemia or any sign of fluid overload postoperatively. The patient maintained adequate urine output in the early as well as the late postoperative course. Total postoperative drainage was 150 ml, of which the max. was in the first 12 hrs and mediastinal drains were removed on the second postoperative day. The patient received a total of 2 units of blood transfusions. Total ICU stay was three days. After an initial rise in serum creatinine upto 7.4 the creatinine and BUN levels stabilized at 4.3 mg% and 80 mg%, respectively. The patient did not require pre or postoperative dialysis and was discharged uneventfully on the 12th postoperative day.

REVIEW OF LITERATURE AND DISCUSSION

Cardiovascular diseases are the second most common cause of death in patients with end stage renal disease after renal failure itself. Most of these conditions require surgical treatment in the form of open-heart surgeries. Special attention is required to address the fluid and electrolyte balance, maintenance of adequate red cell mass, perioperative bleeding diathesis and the timing and route of dialysis when these patients are subjected to cardiopulmonary bypass procedures.[1,4]

As compared to the past there is a reversal of spectrum of cardiac disease in patients with chronic renal failure. Coronary artery disease predominates lately as compared to valvular disease and pericarditis in the past.[4] The better management of uraemia with modern dialysis and the decrease in the incidence of septic complications of dialysis has led to a decrease in the incidence of valvular heart disease to less than 43%, with mitral affection in only 30% of the patients.

Lupus nephritis is a common cause of renal failure in young patients. One third of patients with renal involvement in lupus who present with focal glomerulosclerosis end up having end stage renal disease (ESRD) and even a higher number of cases with diffuse involvement end up so.[10] These cases often have cardiovascular problems needing cardiac surgery. With excellent results of renal transplantation in these cases life expectancy can be prolonged with safe cardiac surgery.

Cardiac surgery in these patients can be challenging, as it requires special care in management of the fluid and electrolyte imbalances, the susceptibility to infection and bleeding diathesis.

Although few recommend dialysis as close to surgery as possible to achieve maximum benefit out of it,[6] or even intraoperative dialysis,[7] most centres perform dialysis at least 24 hrs prior to the surgery to avoid the complication of haemodynamic instability following haemodialysis. We did not dialyze the patient as we had planned haemofiltration during cardiopulmonary bypass.

Lembert et al believed in maintaining adequate red cell mass by preoperative blood transfusions.[8] A blood transfusion is indicated whenever the predicted circulating PCV is less than 24 on cardiopulmonary bypass.[2] Our patient did not require preoperative blood transfusion.

Most centres have used standard cardiopulmonary bypass with moderate hypothermia, crystalloid priming and cold crystalloid cardioplegia for myocardial preservation.[1,3-6,9] However, Ko W et al[2] used cold sanguineous cardioplegia with topical cooling for myocardial preservation. They also report that the amount of potassium given with cardioplegia does not correlate with the serum potassium level at postcardiopulmonary bypass. However, we feel that the systemic hyperkalaemia associated with the use of hyperkalaemic cardioplegia can be a problem while coming off bypass in patients with compromised renal function. We therefore used an external suction to aspirate the effluent of the coronary sinus through a small right atritomy, to avoid systemic hyperkalaemia altogether. Dressler et al recommends dopamine in renal doses while weaning of bypass to improve renal perfusion.[9]

Peritoneal dialysis has as good results as haemodialysis in the postoperative period[4] and is preferred as it avoids haemodynamic instability and the risk of heparin induced bleeding. Ko W et al recommend routine insertion of dialysis catheter in the operating room under anaesthesia for subsequent use in the ICU.[2]

There have been greater tendency for postoperative bleeding in these patients[2,4] with increased requirements of blood, platelets and FFPs. Desmopressin has been shown to reduce the transfusion requirements in these patients[10] however there are contradictory reports.[2]

These patients are also more prone to infection and postoperative ischaemic gastrointestinal complications in the form of GI bleeding or bowel gangrene.[2] Postoperative pericarditis is also common.[2,3] There is a theoretical risk of prolonged anticoagulation associated with mechanical prosthesis as these patients may require frequent puncture for IV access for dialysis purpose[3] however the risk of early calcific degeneration of tissue valves precludes their use in preference to mechanical prosthesis.[9]

CONCLUSIONS

Cardiovascular diseases are one of the commonest causes of death among patients with chronic renal failure. Cardiac surgery can be performed safely and with satisfactory results in patients with chronic renal failure. Lupus Nephritis is one of the common causes of renal failure in young patients and it accounts for almost 30% of the end stage renal diseases seen in younger ones. Most of the patients suffering from Lupus nephritis are young and would need renal transplant in future, which will enhance their survival. It would be mandatory to treat any significant cardiac lesion in these patients before taking them for renal transplant. If the cardiac disease in this patients is treated their life expectancy would be very fair after renal transplant.

While treating the patients with renal failure, the fluid and electrolyte management becomes very important aspect of the treatment. When these patients are put on cardiopulmonary bypass there could be significant amount of fluid overload, as the CP bypass circuit needs to be primed with crystalloids. Use of Ultra filtration in CP bypass circuit is very helpful in filtering the excess amount of fluid from patient’s circulation while coming of bypass and maintaining the optimal amount of fluid in the circulation. Use of ultra filtration can be made to prevent fluid overload associated with haemodilution in cardiopulmonary bypass followed by satisfactory postoperative renal and myocardial function, less tissue oedema and less pulmonary function derangement. This can reduce the postoperative dialysis requirement and help in early weaning from the ventilator. It is well established that the use of mechanical prosthesis is a better choice over tissue valves as the bioprosthetic valves are likely to undergo calcific degeneration very early in these patients. Postoperative dopamine in the renal doses improves renal perfusion and preserves renal function.

REFERENCES

1.Kenneth HL, et al. Cardiac surgery in patients with chronic renal disease. An of Th Surg 1986; 42 : 152-7.

2.Ko W, et al. Cardiopulmonary bypass procedure in dialysis patients. An of Th Surg 1993; 55 : 677-84.

3.Monson BK, et al. Cardiac operations and end stage renal disease. An of Th Surg 1980; 30 : 267-72.

4.Jose, et al. Cardiac surgery in patients with end stage renal disease.

5.Lansing AM. Angina during haemodialysis and treatment with coronary artery bypass grafting. JAMA 1975; 232 : 736-7.

6.Manhas DR, et al. The management of cardiac surgery in patients with chronic renal failure. J Th and Cardiovasc Surg 1972; 62 : 235-9.

7.Soffer O, et al. Intraoperative haemodialysis during cardiopulmonary bypass in chronic renal failure. J Th and Cardiovas Surg 1979; 77 : 789-91.

8.Lamberti J, et al. Cardiac surgery in patients undergoing renal dialysis or transplantation. An Th Surg 1975; 19 : 135-41.

9.Dressler, et al. Open heart operations after renal transplantation. An Th Surg 1997; 63 : 143-6.

10.Brener and Rectors. The Kidney. 5th edition. 2 : 1498-1516.

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