Renal masses are a diverse group of tumors, ranging from benign growths to malignant cancers. Among them, renal cell carcinoma (RCC) is the most lethal urological malignancy, while angiomyolipoma is the most common benign tumor. This study aims to assess the prevalence of acute kidney injury (AKI) following radical nephrectomy for RCC at Ibn Sina Specialized Hospital, Sudan, from 2018 to 2022, using KDIGO guidelines.

A retrospective cross-sectional study was conducted on patients who underwent radical nephrectomy for RCC over the past five years. Data were extracted from hospital records, evaluating renal function before surgery and during the first postoperative week (POD 1-7).

AKI was defined based on the following criteria:

A serum creatinine increase of ≥0.3 mg/dL within 48 hours
A serum creatinine increase of ≥1.5 times the baseline within seven days
Urine output <0.5 mL/kg/h for at least six hours
Patients with pre-existing abnormal eGFR were excluded. A cutoff of 60 mL/min in eGFR was used to define renal function.

A total of 210 patients were included in the study. The prevalence of AKI within POD 1-7 was 29%, with 34.4% of these cases requiring renal replacement therapy. ICU admission was necessary for only 4.9% of patients.

The most common age group affected was 54-64 years (25.7%, p=0.479).
Males were more affected (54.8%, p<0.001).
Most patients originated from northern states (40%, p<0.001).
Overweight BMI was observed in 44.8% of cases (p<0.001).
Common comorbidities included hypertension (14.8%) and peripheral vascular disease (11.9%) (p<0.000).
Frequently used medications included PPIs (36.2%), β-lactams (29.5%), calcium channel blockers (16.2%), and aspirin (7.1%) (p=0.005).
Lifestyle factors included tobacco use (53.3%) and smoking (41.9%) (p<0.001).
Tumor characteristics:

Right-sided tumors were most common (81%, p=0.014).
The predominant tumor size was 5-7 cm (77.6%, p=0.002).
Most tumors were diagnosed at clinical stage T3 (77.6%, p<0.000).
Postoperative findings:

21% of patients experienced reduced urine output.
8.1% had no urine output postoperatively (p<0.000).

The study found that 29% of patients developed AKI after radical nephrectomy, confirming it as a common complication. Male gender, higher BMI, tobacco use, and smoking were identified as significant risk factors, while older age, intraoperative blood loss, and blood transfusion were not associated with AKI.

Among AKI patients, 34.4% required renal replacement therapy, but ICU admissions were low (4.9%). Most tumors were right-sided (81%), sized 5-7 cm (77.6%), and in stage T3 (77.6%).

These findings highlight the need for better preoperative assessments, weight management, and smoking cessation to reduce AKI risk. Future research should explore long-term outcomes and environmental factors influencing renal function post-nephrectomy.

AKI following radical nephrectomy is relatively common. Factors such as male gender, higher BMI, tobacco use, smoking, and geographic origin were associated with increased AKI risk. However, older age, intraoperative blood loss, and the need for intraoperative blood transfusion were not significant risk factors. Monitoring pre- and postoperative renal function can help predict long-term renal outcomes.