The manufacture and application of novel evaluating tool for renal vascular anatomy: the system of individualized reno-vasculature evaluation for nephrectomy

Objective To explore the clinical feasibility and effectiveness of novel preoperative evaluating tool to achieve accurate and quantitative evaluation of renal vascular anatomy for retroperitoneoscopic radical nephrectomy (RLRN). Methods Two-hundred and fifty one consecutive patients who underwent RLRN for renal tumours from September 2016 to March 2018 were enrolled prospectively, including 154 males (61.4%) and 97 females (38.6%), aged 26 to 84 years with the mean age of 58.7 and mean BMI of 25.8 kg/m2. The tumors were all isolated with the mean size of 5.4 cm. According to presence or absence of vascular correlation events (VCE) and nephrectomy times under endoscope (NTE), all the cases were divided into two groups: the common group (VCE, NTE <60 min) and the difficult group (no VCE, NTE ≥60 min). With the help of preoperative three-dimensional reconstruction, the specific and crucial arteriovenous anatomical features were recorded, which consist of side, count, spatial configuration and density of the vessel to be processed. After univariable analysis, multivariable analysis with logistic regression was performed for the selected risk factors. Individualized reno-vasculature evaluation for nephrectomy were established, when the value of risk factors were assigned separately according to its correlation and clinical practice. Results There was no statistical significance between common group and difficult group in the aspects of gender, age, BMI, maximum diameter of the tumor, R. E.N.A.L. score and PADUA score. There were statistical significance between common group and difficult group in the aspects of N (number of total vessels), D (vascular anomalies density), C (3D conformation), S (sides) of pending renal vessels (χ2=125.700, 102.014, 97.090, 12.603, P 0.05). SIREN was preliminarily established as a preoperative evaluating tool to achieve accurate and quantitative evaluation of renal vascular anatomy. Of the 5 components of SIREN, N, D were scored on 1 to 3 points, C was scored on 0 to 3 points, E was scored on 0 to 1 point, and S was not scored but showed in terms of L or R. All of these constitute the assessment content with a full score of 10 points except S suffixed by L or R instead of scores. There was a statistically significant difference during low (2-3 points), middle (4-6 points), and high (7-10 points) groups (χ2=126.927, P<0.05) according to the comparisons between low and middle, low and high, as well as middle and high (χ2=90.997, 7.195, 91.679, P<0.05). Conclusions In virtue of the renal vascular scoring system named after SIREN by 3d reconstructing, the spatial structure information of the renal vascular system can be obtained accurately and expressed directly before operation, the difficulty of vascular treatment can be predicted, the preoperative planning can be optimized, and the accurate quantitative evaluation of renal vascular anatomical structure can be achieved to further improve the surgical safety and efficiency. Key words: Laparoscope; Nephrectomy; Influence factor; Renal vascular; Scoring standard