EXPERIMENTAL AND CLINICAL TRANSPLANTATION

This case report shows the vital importance of vigilant observation of patients after transplant. In centers where ultrasonographs are not available, exploration of the patient may be necessary to salvage a precious kidney. In the patient reported here, who received a kidney transplant at St. Nicholas Hospital in Lagos (Nigeria, Africa), reexploration resulted in an increased area for the kidney, with both improved urine output and graft function.

Key words : Reexploration, Renal transplant, Ultrasonography

Successful renal transplant remains the optimal treatment for chronic kidney failure in pediatric patients with end-stage renal disease. It has been observed that outcomes in pediatric transplantation are nearly identical to those in adults due to improvements in surgical techniques and immunosuppressant application.

A 12-year-old male patient presented with elevated blood pressure, creatinine level of 748 μmol/L, urea level of 29.7 mmol/L, potassium level of 5.2 mmol/L, and sodium level of 132 mmol/L. A computed tomography urography revealed minimal excretion from both kidneys, and he subsequently required hemodialysis. A significant deterioration in his condition followed, and the patient underwent a living donor kidney transplant from his aunt in December 2020 at St. Nicholas Hospital in Lagos (Nigeria, Africa).

Immediately after the transplant procedure, the patient showed adequate urine output, but output decreased several hours posttransplant. An urgent renal Doppler ultrasonography was performed at bedside that revealed poor flow requiring a surgical reexploration. Upon exploration, the compressed kidney revived immediately, resulting in improved graft function and urine output. Creatinine levels improved consistently throughout his hospital stay, and he was discharged 16 days later.

Renal transplant is an established procedure with optimal success rates globally. The advent of improved immunosuppressive techniques has resulted in a reduction of graft loss due to both chronic and acute rejection. However, access to kidney transplant has a wide variance across the world, with only a rate of 21% in low- and middle-income countries; numbers have been reported to be as low as 4 per million child population for pediatric cases.¹ Kidney transplant rates in adults per million population are 7.25 and 1.33 in South East Asian countries and Africa, respectively. This contrasts with America and Europe, which have rates of 40.54 and 35.53 per million population, respectively.² The challenge associated with this disparity lies in the long-term outcomes after transplant in contrast to the short-term graft survival, where rates are comparable to high-income countries. The long-term care requirements, financial burden, and limitations to health care professionals that accompany transplantation in underresourced countries are an obstacle to achieving and strengthening success rates to be comparable with those in high-income countries.

To evaluate the stability of the transplanted kidney postoperatively, several markers are assessed, which can allow prevention of both acute rejection and infection. These include serum creatinine levels, glomerular filtration rate, proteinuria, and immunosuppressive treatment. Approximately 3 to 6 months following transplant, preservation of donor kidney function and prevention of complications to immunosuppressive medications become the forefront of management. Complications can include cardiovascular disease, infection, blood disorders, and cancer. The use of the renal transplant ultrasonography (renal Doppler) is a beneficial tool for evaluation of any surgical or medical complications that may arise posttransplant.3 In the case of the patient reported here, the bedside ultrasonography on day 1 posttransplant highlighted the urgency of the compressed kidney and enabled timely intervention during reexploration to manage the complication.

Surgical reexploration after kidney transplant is most commonly required on posttransplant day 1.⁴ Increased hospitalization duration, decreased graft function and urine output, and increased mortality are often associated risks that accompany such a procedure. The compression of the kidney in this case was due to the large size of the kidney having been donated by an adult. A disparity in age and size can pose difficulties in that the heart, blood volume, and vessels are not sufficient to satisfy the demand of an adult-sized kidney when transplanted, which can result in risks of rejection should blood clots develop in the kidney.⁵ It is further postulated that larger kidneys result in immunological privilege, whereby a greater mass of donor tissue consumes the immune system of the recipient and enables the transplanted organ to be successful.⁵ This can thereby reduce the dose of immunosuppressive drugs required to be administered to children following transplant to avoid rejection. During reexploration, risks to the patient were reduced, and both urine output and graft function were improved as a result of increasing the area in which the kidney was placed.

Other complications that may arise during kidney transplant include urologic complications, urine leak and urinomas, hematomas, abscesses, lymphoceles, and peritransplant fluid collections.⁶ Urological complications result in patients requiring ureteroureterostomy or pyeloureterostomy to achieve continuity of the urinary tract. This type of complication is associated with patient mortality rates of 4% to 8%. Urine leaks and urinomas may occur due to vascular insufficiency or increased urinary pressures. A decrease in urinary output may be suggestive of a urine leak having occurred, and an ultrasonography would reveal a fluid collection that rapidly increases in size with time. Small hematomas can often develop spontaneously and usually resolve without treatment; however, larger hematomas can result in displacement of the transplanted kidney. Lymphoceles form the majority of peritransplant fluid collections and can develop at any point after transplant despite usually being an early complication within 1 to 2 months postoperatively. They are caused by lymph leakage from lymphatic channels or from the lymphatics of the kidney that have been affected during surgery.⁶

This case report shows the vital importance of a vigilant observation of patients after transplant. In centers where ultrasonographs are not available, exploration of the patient may be necessary to salvage a precious kidney. In our patient, 2 years posttransplant, his kidney function is perfect, and he remains under close observation.

Volume: 20 Issue: 5 May 2022 - Supplement - 3

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