The natural history of solitary post-nephrectomy kidney in a pediatric population

ABSTRACT Introduction: Children with a solitary post-nephrectomy kidney (SNK) are at potential risk of developing kidney disease later in life. In response to the global decline in the number of nephrons, adaptive mechanisms lead to renal injury. The aim of this study was to determine the prevalence and time of onset of high blood pressure (HBP), proteinuria, glomerular filtration rate (GFR) disruption and renal tubular acidosis (RTA) in children with SNK. Materials and methods: After obtaining the approval from our institution's ethics committee, we reviewed the medical records of patients under 18 years of age who underwent unilateral nephrectomy between January 2005 and December 2015 in three university hospitals. Results: We identified 43 patients, 35 (81.4%) cases of unilateral nephrectomy (UNP) were due to a non-oncologic pathology and Wilm's tumor was identified in 8 (18.6%) cases. In patients with non-oncologic disease, 9.3% developed de novo hypertension, with an average time of onset of 7.1 years, 25% developed proteinuria de novo, with an average time of onset of 2.2 years. For GFR, 21.8% presented deterioration of the GFR in an average time of 3.4 years. Ten (43.5%) patients developed some type of de novo renal injury after UNP. Patients with oncologic disease developed the conditions slowly and none of them developed proteinuria. Conclusions: Taking into account the high rate of long term postoperative renal injury, it can be considered that nephrectomy does not prevent this disease. The follow-up of children with SNK requires a multidisciplinary approach and long-term surveillance to detect renal injury.

摘要
## 引言
肾切除术后孤立肾（solitary post-nephrectomy kidney, SNK）患儿日后罹患肾脏疾病的潜在风险较高。由于肾单位总量减少，机体的代偿机制可引发肾损伤。本研究旨在明确肾切除术后孤立肾患儿的高血压（high blood pressure, HBP）、蛋白尿、肾小球滤过率（glomerular filtration rate, GFR）异常以及肾小管酸中毒（renal tubular acidosis, RTA）的患病率与发病时间。

## 材料与方法
本研究经本院伦理委员会批准后，回顾性分析了2005年1月至2015年12月间，三家大学附属医院中18岁以下接受单侧肾切除术患者的病历资料。

## 结果
本研究共纳入43例患者，其中35例（81.4%）的单侧肾切除术（unilateral nephrectomy, UNP）病因非肿瘤性，8例（18.6%）确诊为肾母细胞瘤（Wilm's tumor）。在非肿瘤性病因患者中，9.3%出现新发高血压，平均发病时间为7.1年；25%出现新发蛋白尿，平均发病时间为2.2年。针对肾小球滤过率，21.8%的患者出现GFR下降，平均耗时3.4年。10例（43.5%）患者在单侧肾切除术后出现了不同类型的新发肾损伤。肿瘤性病因患者的病情进展较为缓慢，且无一例出现蛋白尿。

## 结论
鉴于术后远期肾损伤发生率较高，可认为肾切除术并不能预防此类疾病的发生。肾切除术后孤立肾患儿的随访需采用多学科协作模式，并进行长期监测以早期发现肾损伤。