To allow improved quality of life, renal transplant has been regarded as the best therapeutic option for patients with end-stage renal disease. However, due to shortages of renal sources, annually, only a few patients with renal failure can receive transplants, with most patients requiring hemodialysis to maintain their life. With increasing imbalance of demands and supplies for donor organs, infant organ donors have become an important part of domestic and foreign transplant sources. It is of great importance to guarantee successful kidney transplant outcomes. Examination of the size and blood perfusion of the transplanted kidneys in an accurate and timely manner and early detection of postoperative complications can improve survival rates and quality of life. Here, we report a rare double kidney transplant with the kidney of a 6-month-old infant and the great technical difficulties. Color Doppler ultrasonography played an important role in dynamic observations of the size of the kidney, blood perfusion, spectral index, and detection of complications after transplant.
Key words : Complications, Infant donor kidney, Renal transplant
Infant donors have become an important source of organs for domestic and foreign transplant. Different from conventional kidney transplant procedures, transplants for adult recipients of infant kidneys have high operation difficulties, and there may be high risks of complications, including insufficient kidney function, high perfusion injury, artery-venous thrombosis or bleeding, uronephrosis, and urinary fistula. After kidney transplant, bedside ultraso-nography and Color Doppler ultrasonographic technologies are regularly used. Two-dimensional color Doppler flow imaging and spectrum Doppler imaging technologies can help to detect the size of the kidney, blood flow frequency, and complications such as artery-venous thrombosis, bleeding, and uro-nephrosis. These techniques also guide physicians during early care of patients, allowing them to make dynamic assessments regarding effects of treatment.
Our case patient, a 63-year-old woman, had a 10-year history of hypertension, creatinine level of over 1200 μmol/L, and urea nitrogen level of over 32.5 mmol/L. She had started hemodialysis in 2010, increasing from once per week to 3 times week at time of transplant. She also took 5 mg of oral amlodipine besylate and 20 mg of metoprolol every day. Her physical examination showed temperature of 36.2℃, pulse of 84 beats/min, respiratory rate of 20 breaths/min, and blood pressure of 160/110 mm Hg. She was conscious but had presented with chronic nephrosis with artery and vein fistulas seen in the front of her left arm. She was admitted to the hospital due to (1) chronic renal insufficiency, (2) uremic syndrome, (3) renal hypertension, and (4) renal anemia and was placed on the allograft kidney transplant wait list.
She received preoperative ultrasonography (LOGIQE9, GE Healthcare Life Sciences, Little Chalfont, UK) with an ultrasonography probe (probe C1-C5; frequency of 2.0-5.0 MHz; mechanical index of 0.11), which showed left and right kidney sizes of 6.8 cm × 3.6 cm × 3.4 cm and 6.8 cm × 3.3 cm × 3.2 cm, respectively, with renal parenchyma thickness of about 0.9 cm and 0.9 cm, respectively. The corticomedullary differentiation was not clear, and the parenchyma echo increased with no obvious color blood flow signal or artery or vein pulse spectrum signal detected.
The patient received transplant via the right fossa iliaca with a kidney donation from a 6-month-old infant. After the kidneys of the deceased pediatric donor were retrieved, they were first irrigated with heparinized Ringer lactate. The kidneys were then placed extraperitoneally in the iliac fossa of the recipient via a Gibson incision. The vena cava of the donor kidney fit the vena iliaca externa of the recipient with 5-0 Prolene suture from side to end of veins; the arteria iliaca externa fit the artery of the donor kidney with 6-0 Prolene suture from side to end of artery. The ends of the two ureters were anastomosed medially together, and then uretero-neocystostomy was performed using the Lich-Gregoir extravesical technique. Ureteral stents were placed for 4 to 6 weeks. The ureteral catheter was removed 5 days posttransplant.
Ultrasonography was performed on day 1, day 20, and day 45 posttransplant. Table 1 lists the sizes, cortical thicknesses, and parenchyma thicknesses of both transplanted kidneys. Scan showed no obvious opaque/dark areas of fluid. Color Doppler flow imaging showed abundant color blood flow signals in both the first and second kidney. Blood flow signals were shown in the inherent artery, segmental artery, and interlobular arteries (Figure 1A and 1B). At day 45 posttransplant, we were able to view the frequency spectrum of the kidney’s arteries. Table 2 lists the peak systolic velocity, end-diastolic velocity, and resistance index (Figure 1C).
Figure 1D, 1E, and 1F show the ultrasonography and computed tomography angiography results. After 45 days of dynamic assessment, we observed no obvious rejection. Ultrasonographic monitoring made it possible to observe development of the transplanted kidneys, understand changes in the internal structure, and view blood flow, its frequency spectrum, and its resistance index. Being able to make a dynamic assessment of the donor’s kidneys allowed us to make timely suggestions and prevent complications.
Kidney transplant is commonly recognized as the most ideal means to treat end-stage renal failure. At present, patient survival after renal transplant has greatly increased; however, shortages of donor kidneys have seriously restricted organ transplant globally. Although living-donor kidney transplant and expansion of standard donor kidney transplant have expanded donor kidney sources, there are still more people on kidney transplant wait lists than the number of donor kidneys.1 Statistical analyses have shown2 that the average mortality rate of end-stage renal disease is 6%, with about 50% of elderly patients dying while waiting for a kidney transplant. With the increase of donations after cardiac death and the rapid development of transplant techniques, the number of deceased pediatric kidney donors has also increased every year, opening up a new way for donor kidney sources.
Pediatric en bloc kidney transplant is a safe and reasonable transplant surgery option.3 Vascular complications after renal transplant is a common problem in procedures involving kidneys from pediatric donors, especially infants, which is mainly attributable to renal artery thrombosis and anasto-motic stenosis, which have reported incidence rates of 4.2% to 11%.4,5 This complication is the main cause of damage to renal function or even the failure of function.6 Therefore, a key for improved survival is monitoring of blood perfusion, the rejection action, the vessels, and anastomotic stenosis, to allow early and accurate diagnosis and to offer reasonable treatment. Due to its convenience, safety, and ability to be repeated and its ability to provide dynamic assessments, ultrasonography has become the most common way for examination. Ultrasonography can allow clinicians to fully understand the structure of the kidney transplant and its complications. Color Doppler flow imaging and frequency Doppler flow imagining techniques can provide more sensitive results.7,8 Therefore, the use of color Doppler flow imaging can help observation of blood perfusion and several flow indexes and early detection of complications, as well as allow effective guidance regarding treatment.
DOI : 10.6002/ect.2018.0288
From the Department of Ultrasound, Zhongnan Hospital of Wuhan University, Wuhan,
Hubei, P.R. China
Acknowledgements: The authors have no sources of funding for this study and have no conflicts of interest to declare.
Corresponding author: Meng Wu, Department of Ultrasound, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China
Phone: +86 136 3868 7312
Table 1. Changes in Sizes of Donor Kidneys Over Time After Transplant
Table 2. Spectrum of Artery Findings From Donor Kidneys
Figure 1. Ultrasonographic and Computed Tomography Findings