Renal Transplant Complications

Published on 14/03/2015 by admin

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Last modified 14/03/2015

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117 Renal Transplant Complications

• Renal transplantation is highly successful. With appropriate immunosuppressive therapy, the rate of acute rejection during the first posttransplant year is less than 25%; 1-year survival rates approach 100%.

• Surgical complications that may be seen in the emergency department include hematoma formation, ureteral anastomotic leak, and ureteral obstruction. Computed tomography is the diagnostic imaging modality of choice for these surgical emergencies.

• Surgical infections that are common in the first posttransplant month include pneumonia, line sepsis, and wound infection. Opportunistic infections reach their peak incidence during the remainder of the first posttransplant year. After the first year, community-acquired infections predominate.

• Renal transplant patients have a high risk for atherosclerotic disease. Cardiovascular conditions account for 30% to 50% of deaths during the first posttransplant year.

• Fluoroquinolones and macrolides may increase levels of cyclosporine and tacrolimus; these antibiotic classes should not be used as first-line agents for the treatment of patients with posttransplant pneumonia.

• Fever and tenderness over the graft site may indicate acute rejection.

• Transplant recipients treated with corticosteroid therapy have functional adrenal insufficiency and require pulse doses of corticosteroids when they encounter physiologic stress.

Epidemiology

The kidney is the most commonly transplanted solid organ. According to the U.S. Organ Procurement and Transplantation Network, more than 298,260 kidney transplants have been performed to date.¹ It is important that providers have a general understanding of the expected surgical and medical complications commonly observed in posttransplant patients.

Developments in Renal TransplantationS

The primary indication for renal transplantation is stage V chronic kidney disease (formerly called end-stage renal disease). Transplantation is recognized as the most effective form of renal replacement therapy for these patients.

Specific disease entities that causing chronic kidney disease are outlined in Box 117.1. Diabetic nephropathy is the most common single disease process leading to renal transplantation.¹

Box 117.1 Diseases Leading to Renal Transplantation

Chronic kidney disease

Polycystic kidney disease

Rapidly progressive glomerulonephritis

Toxic nephropathies

Most renal grafts now function for longer than 10 years. The 1-year survival rate of renal transplant recipients is 95% to 98%. Renal transplants are more effective than hemodialysis at prolonging the life of patients with chronic kidney disease.²

Previously, the highest surgical success rates were achieved with histologically matched donor kidneys from a living recipient. Advances in immunosuppressive medication regimens have improved the success rate of cadaveric kidney transplantation, which now approaches that seen with living donors.

Preoperative clearance for renal transplantation is extensive. For patients with cancer, the suggested disease-free interval before transplantation is 5 years. Infection with human immunodeficiency virus is considered a contraindication to renal transplantation in many institutions, although transplantation has been successful in many patients with well-maintained CD4⁺ T-cell counts.

Cholecystectomy was previously performed in all patients undergoing renal transplantation. Currently, cholecystectomy is performed only in patients with evidence of cholelithiasis or cholecystitis.

The surgical approach to renal transplantation varies with the age of the patient, as well as with the location of the kidney and the anastomosis. The recipient’s native kidneys and collecting system are generally left in place unless there is another indication for nephrectomy. The donor kidney is placed in one of the lower abdominal quadrants (more commonly the right), and the ureter is anastomosed to the bladder; arterial and venous anastomoses generally arise from the iliac vessels, aorta, or inferior vena cava. The transplanted kidney is usually palpable on abdominal examination.

Immunosuppression is initiated after transplantation and is divided into two phases: induction and maintenance.³ Agents such as tacrolimus and monoclonal and polyclonal antibodies are often included in the induction and maintenance phases of treatment (Box 117.2). With the use of immunosuppressive medications, the 1-year incidence of acute rejection is 15% to 25%.

Complications

Complications of renal transplantation can be categorized by cause as either surgical or medical and further divided by time of occurrence as either early or delayed.

Surgical Complications

Surgical complications include graft malfunction, thrombosis, aneurysms of the graft vessels, and stricture or obstruction of the ureter. Some of these complications will be evident shortly after surgery; others may occur years after the procedure and cause symptoms that will probably prompt emergency department (ED) evaluation.

Graft function may be delayed in up to 30% of cadaveric transplants, probably as a result of prolonged cold ischemia of the kidney during the period between harvesting and transplantation.⁴ Delayed graft function is a rare complication with living donor transplants. Patients may require continued dialysis until adequate posttransplant function is demonstrated.

Acute thrombosis of the arterial or venous anastomoses is usually seen within the first posttransplant week.^3,⁴ Treatment is surgical exploration in an attempt to salvage the donor kidney.

Renal artery stenosis has been reported in allografts and can cause hypertension in posttransplant patients. This is generally a delayed complication. Aneurysms of the graft vessels are uncommon, delayed events.

Hematomas may develop around the transplanted kidney. Hematoma formation may be an early postoperative complication or rarely may result from acute rejection with spontaneous rupture of the kidney.⁴ Acute hematomas are surgical emergencies.

Ureteral complications include anastomotic leakage (generally within the first posttransplant month), acute ureteral obstruction, and lymphocele. These complications will occur within the first 3 months following transplantation. Computed tomography of the abdomen is the preferred imaging modality for ureteral complications. Ureteral obstruction often requires emergency surgical intervention.

Medical Complications

Medical complications are numerous and often subtle. Posttransplant patients are at risk for atypical infections, cardiovascular death, renal failure, and rejection. Adverse reactions from immunosuppressive medications account for many delayed medical complications in transplant patients.

Fever

Management of fever in posttransplant patients should be approached similar to that of fever in other immunocompromised patients.⁵ Because of suppressed immunologic and inflammatory responses, posttransplant patients may not exhibit the common findings of acute infection. Fever may or may not be associated with clinically significant infection.

Acute rejection is one cause of fever that may develop at any time. Decisions regarding appropriate diagnostic testing and disposition of a posttransplant patient with fever should be made in consultation with a transplant service.

Infections

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