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Objective:To explore the clinical characteristics, causes, diagnosis and treatment of transplant renal artery stenosis after pediatric-to-adult kidney transplantation.Methods:Between July 2014 and March 2019, clinical data were retrospectively reviewed for 25 en-bloc and 27 single kidney transplant cases.Results:One en-bloc(4.0%)and two single kidney recipients(7.4%)were diagnosed as renal artery stenosis at Month 13-23 months post-transplantation.It was higher than the rate of stenosis in adult-to-adult transplant cases(1.1%)during the same period.As compared with recipients without stenosis, stenotic ones had younger pediatric donors( P<0.05)and yet similar body weight of donors as well as recipients( P>0.05). The inner diameters of stenonotic sites were(1.40-1.63)mm and predominant stenotic site was proximal renal artery rather than anastomotic site.The remaining parts of major renal arteries varied from 2.31 to 4.93 mm in diameter.It was normal in children with a corresponding age.All three cases responded well to percutaneous transluminal angioplasty and stenting. Conclusions:The cause of stenosis may be an undeveloped local artery diameter due to extensive tissue dissection around artery.Therefore cautious selections of infantile single renal graft for adult recipients and preserving surrounding tissue of renal artery assist in the prevention of graft arterial stenosis.
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Objective:To explore the clinical efficacy of vascular interventional therapy in children with transplantation renal artery stenosis(TRAS).Methods:From January 2013 to September 2021, retrospective analysis was performed for clinical data of 238 TRAS children.Peak systolic velocity(PSV)of transplant renal artery, interlobular artery PSV, transplant renal artery PSV/ interlobular artery PSV(post PSV ratio)and serum creatinine level before and after vascular interventional therapy and at the last follow-up were compared.Results:Six pediatric kidney transplantation recipients were diagnosed as TRAS.The median operative age was 12(9-17)years, the median postoperative time to diagnosing TRAS 4(1.7-18.0)months and the median follow-up period 6.6(2.5-8.0)years.All of them received vascular interventional therapy of percutaneous transluminal angioplasty(PTA, n=5)and stent angioplasty( n=1). The serum creatinine pre-treatment with vascular interventional therapy was significantly higher than baseline serum creatinine level at discharge(200.8±88.5)vs(75.2±27.9)μmol/L, P=0.025 and decreased to(103.8±44.7)μmol/L at Month 1 post-treatment( P=0.196)and(98.7±30.2)μmol/L at the last follow-up( P=0.115). Comparing with internal diameter of grafted renal artery anastomosis site(2.6±0.6 mm)pre-treatment with vascular interventional therapy, significant changes occurred at 24 h post-treatment(3.8±0.5 mm)and at the last follow-up(4.1±0.8 mm)(all P=0.027). In addition, PSV and post PSV ratio of transplanted renal artery at 24 h post-treatment(163±45.0 cm/s, 6.5±2.2)and at the last follow-up(184.7±80.8 cm/s, 5.4±2.0)were significantly lower than that before vascular interventional therapy(356.5±77.9 cm/s, 18.0±5.8)and interlobular artery PSV was significantly higher than that before vascular interventional therapy( P=0.024, P=0.032, respectively). During follow-ups, no restenosis or thrombosis occurred in transplanted renal arteries. Conclusions:PTA or stent angioplasty for TRAS children is technically feasible with low restenosis rate and relatively satisfactory mid/long-term outcomes.
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Objective:To explore the clinical features of transplanted renal artery stenosis after pediatric donor kidneys in children.Methods:We retrospectively summarized the clinical data in five cases of transplanted renal artery stenosis undergoing deceased pediatric donor kidney transplantation from May 1, 2014 to June 30, 2021.Donor/receptor characteristics, diagnosis, treatment and prognosis were recorded.The median follow-up period was 29 months.The median age of five donors and recipients was 9 and 132 months respectively.En bloc renal allograft( n=2)and single kidney transplantation( n=3)were performed.End-to-side anastomosis was performed for renal arteries.The median diagnostic time of renal artery stenosis was 10(3-60)months post-transplantation.Except for one 3-year-old recipient with an earlier onset of stenosis, four stenotic cases during a rapid growth period had a maximal height increase of 30 cm post-transplantation.Three of them had a history of surgery at graft site, including previous kidney transplantation( n=1)and transplant urinary tract reconstruction( n=2). All five cases had hypertension and two showed an elevated serum level of creatinine.Ultrasound indicated a significantly elevated flow rate of >300 cm/s( n=4)and CTA/MRA indicated that the degrees of stenosis varied from 50% to 95%( n=5). Results:After balloon dilatation, stenosis either improved( n=2)or relapsed( n=2). Further stenting succeed( n=1)or failed( n=1). One case of stenosis was relieved partially after 6-month observation without any invasive treatment. Conclusions:As a serious complication, transplant renal artery stenosis is common after pediatric donor kidney transplantation.Too small size in donor kidney and rapid recipient growth may be specific risk factors.After diagnosis, balloon dilation is a preferred treatment.Stent placement should be cautiously employed.