Introduction

Adult-size kidneys are usually used for kidney transplantation in small pediatric recipients, but the influence of graft size in transplant outcome remains controversial. Our aim is to compare long-term transplant outcomes of using adult-size and size-matched kidneys in small pediatric recipients.

Materials and methods

Since 1999, 61 of 226 kidney transplants were achieved in recipients weighing <20 kg with 5 years of follow-up. Patients were analyzed according to the graft size received: (group-A) adult-size (n = 32), (group-B) size-matched (n = 29). Kidney size (KS), glomerular filtration rate (GFR) proteinuria and rejection were compared between groups at transplant time (T₀), at one (T₁), two (T₂), five years (T₅), and at the end of the follow-up (T_F) (median follow-up 8.47(0–17) years). Graft and patient survival were determined and compared between groups.

Results

Mean KS was significantly different between groups at T₀ (A:11.3 ± 1.1 cm, B:8.8 ± 0.9 cm), (pT₀<0.01), group-B evidenced graft growth, reaching similar sizes to group-A at T₅ (A:11.7±1 cm, B:11.2±1 cm; pT₅ = 0.13) and T_F (A:12.2 ± 1.1 cm, B:12.4 ± 1.2 cm; pT_F = 0.63), and group-A had a slight graft growth at T_F (pT₀-T_F<0.01). Mean Schwartz-GFR at T₀ was greater in group-A (138 ± 33 ml/min/1.73 m²) than group-B (109 ± 34 mL/min/1.73 m²) (pT₀ = 0.01); during follow-up, it evidenced a reduction in group-A (T₅:90 ± 27, T_F:71 ± 24 mL/min/1.73 m²; pT₀-T₅<0.01; pT₀-T_F<0.01), meanwhile in group-B was stable until T₅ (104 ± 33 mL/min/1.73 m²; pT₀-T₅ = 0.54), declining at T_F (76 ± 31 mL/min/1.73 m²; pT₀-T_F<0.01); with no significant differences at T₁, T₂, T₅, and TF between groups. Similar results were observed in mean Filler-GFR of both groups (Figure). Proteinuria and episodes of rejection were no significantly different between groups during the follow-up (p > 0.01; p = 0.23). Graft and patient survival at 5 and 10 years did not show significant differences (p = 0.45; p = 0.10).

Discussion

Despite the initial kidney size difference between groups, we have demonstrated that they tended to the same size during the follow-up. Adult-size kidneys presented a slight size increase in the long-term, suggesting that they have some growth potential in small recipients, in contrast to previous literature. Mean GFR between groups showed no significant differences in the long-term, suggesting that optimal graft perfusion and function can be achieved despite the size of the graft. We have demonstrated that there were no significant differences in long-term graft and patient survival; this results were similar to the most recent literature about this topic and different from the 90–2000s decades literature.

Conclusions

Adult-size kidneys may be transplanted to small recipients (<20 kg) with comparable outcomes to size-matched kidneys, with no significant differences in long-term KS, GFR, proteinuria, rejection, graft or patient survival.

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Summary Figure. Mean kidney size (cm), mean Swartz-GFR (mL/min/1.73m²) and mean Filler-GFR (mL/min/1.73m²) of groups A and B during the study. (Group-A: Adult-sized graft group; Group-B: Size-matched group; T0: at transplant; T1: first year; T2: second year; T5: fifth year; TF: at the end of the study).

中文翻译：

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小儿接受者的成人大小和大小匹配的肾脏移植的长期结果。

介绍

成年大小的肾脏通常在小儿科接受者中用于肾脏移植，但是移植物大小对移植结果的影响仍然存在争议。我们的目的是比较在小儿科接受者中使用成人大小和大小匹配的肾脏的长期移植结果。

材料和方法

自1999年以来，经过5年的随访，在体重＜20 kg的受者中完成了226例肾脏移植中的61例。根据接受的移植物大小分析患者：（A组）成人大小（n = 32），（B组）大小匹配（n = 29）。比较两组在移植时间（T ₀），一个（T ₁），两个（T ₂），五年（T ₅）和移植时的肾脏大小（KS），肾小球滤过率（GFR）蛋白尿和排斥反应。随访结束时间（T _F）（中位随访时间8.47（0-17）年）。确定移植物和患者存活率，并在各组之间进行比较。

结果

在T ₀（A：11.3±1.1 cm，B：8.8±0.9 cm）时，各组之间的平均KS显着不同（p T ₀ <0.01），B组证明了移植物的生长，在T时达到了与A组相似的大小₅（A：11.7±1 cm，B：11.2±1 cm; p T ₅  = 0.13）和T _F（A：12.2±1.1 cm，B：12.4±1.2 cm; p T _F  = 0.63），以及- A在T _F处有轻微的移植物生长（p T ₀ -T _F <0.01）。A组（138±33 ml / min / 1.73 m ²）在T ₀时的平均Schwartz-GFR大于B组（109±34 mL / min / 1.73 m ^2））（p T ₀  = 0.01）; 随访期间，它证明在组-A（减少Ť ₅：90±27，T _˚F：71±24毫升/分钟/1.73米² ; p Ť ₀ -T ₅ <0.01; p Ť ₀ -T _˚F <0.01），与此同时，B组稳定至T ₅（104±33 mL / min / 1.73 m ²；p T ₀ -T ₅  = 0.54），在T _F（76±31 mL / min / 1.73 m ）下降。² ; p T ₀ -T _F<0.01）; 两组之间在T ₁，T ₂，T ₅和TF上没有显着差异。两组的平均Filler-GFR观察到相似的结果（图）。随访期间两组之间的蛋白尿和排斥反应差异无统计学意义（p  > 0.01；p  = 0.23）。5年和10年的移植物和患者生存率无显着差异（p  = 0.45；p  = 0.10）。

讨论区

尽管各组之间最初的肾脏大小不同，但我们已证明在随访期间它们倾向于相同的大小。长期来看，成年大小的肾脏大小略有增加，这表明与先前的文献相比，它们在小接受者中具有一定的生长潜力。两组之间的平均GFR长期显示无显着差异，这表明尽管移植物的大小也能实现最佳的移植物灌注和功能。我们已经证明长期移植物和患者的存活率没有显着差异。该结果与有关该主题的最新文献相似，并且与90-2000年代的几十年文献不同。

结论

成人大小的肾脏可以移植到较小的接受者（<20 kg），其结果与大小匹配的肾脏相当，长期KS，GFR，蛋白尿，排斥反应，移植物或患者存活率无显着差异。

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摘要图。在研究期间，A组和B组的平均肾脏大小（cm），平均Swartz-GFR（mL / min / 1.73m ²）和平均Filler-GFR（mL / min / 1.73m ²）。（A组：成年移植组； B组：大小匹配组； T0：移植时； T1：第一年； T2：第二年； T5：第五年； TF：研究结束时）。