# Evaluation of Chronic Kidney Disease Risk Factors after Radical Nephrectomy
## 1 Introduction  
The kidney is an essential organ for maintaining proper water, electrolyte balance, blood pressure and adequate ridding of waste products in the human body. Worldwide, kidney cancer is the third most common urological malignancy preceded by prostate cancer and bladder cancer, with the largest prevalence in Europe and North America. Amid population growth, aging and improved routine diagnostics, incidence rates of kidney cancer are increasing globally, with some variation between different regions [1]. Theestimated incidence of kidney cancer increases roughly 0.5% per year of age peaking between the ages 60 and 70 and is more prevalent in males than females (1.5:1) across all age groups [2]. Despite progress being made in understanding the pathology, morphology and natural history of kidney neoplasms, the etiology of renal cancer remains unknown. While there is no recommendation for the screening and primary prevention of renal cell carcinoma (RCC), the extensive use of non-invasive abdominal imaging methods has led to improved early detection of localized kidney tumors. Risk factors for the incidence of RCC are fairly well-studied and include smoking, obesity, hypertension (HTN) and diabetes mellitus (DM) [3; 4; 5]. Mortality of RCC is higher in patients who smoke and consume alcohol [3]. The typical age of patients with RCC is about 64 years with near-normal distribution [6]. In young patients, hereditary kidney cancer syndromes should be suspected [7; 8]. Approximately 5-8% of RCC cases are known to be hereditary [9]. In the management of RCC with the increasing use of a minimally invasive operative approach and nephron-sparing surgery techniques, radical nephrectomy (RN) is performed less frequently. However, this type of kidney surgery remains the preferred treatment method for patients with large (T2) tumors; tumor thrombus and kidney masses cannot be safely removed during partial nephrectomy (PN) [10]. RN is also a method of choice for treating RCC with vascular invasion and thrombosis of the inferior vena cava (IVC) occurring in 4-10% of the cases [11]. RN is performed by removing the affected kidney within Gerota's fascia, and sometimes lymphadenectomy and the ipsilateral adrenal gland. No significant differences in oncological outcomes of open versus laparoscopic RN were reported; however, laparoscopic RN is associated with a shorter hospitalization time, reduced blood loss and lower postoperative demand for analgesics than open RN [10]. However, even when generally accepted criteria for selection are met, some patients do poorly after surgery due to a decline in renal function (RF). CKD is a progressive disease, which, if untreated, leads to kidney damage and the need for transplantation or dialysis due to the loss of RF [12]. Damage to kidneys eventually leads to a significant risk of all-reason mortality [13]. Thus, the evaluation of individual risk factors can be invaluable for both patient and surgeon when discussing possible treatment options and follow-up plans. Intraoperative hypotension (IOH) caused by anesthetic induction, a common event during non-cardiac surgery, can decrease RF [14]. During RN, IOH can appear due to kidney removal and intraoperative blood loss. Some studies showed that controlled IOH was related to a higher rate of acute kidney injury (AKI) after surgery [15; 16]. However, none of the previous studies analyzed the IOH effect on CKD after RN. Surgery remains the leading cause of AKI in an inpatient setting. Even when the course of surgery is uncomplicated, AKI may occur due to transient renal hypoperfusion, which reduces the glomerular filtration rate (GFR) [17; 18; 19]. With the persistence of intraoperative hypotension, as physiological adaptation mechanisms are exhausted, renal ischemia begins to develop. An inadequate oxygen supply to the cells and inadequate production of ATP leads to eventual necrosis of the nephrons.