Risk factors for nephrolithiasis after radical cystectomy with intestinal plasty of the bladder.

Abstract

Introduction. Some studies have shown that urolithiasis is much more common in the group of patients who underwent radical cystectomy (RC) with intestinal plastic bladder than the average for the population. The aim of this study included the search of the frequency of urinary stones formation in patients after RC, depending on the type of intestinal plasty of the bladder and the type of urinary diversion, the analysis of risk factors for lithogenesis, the search for metabolic lithogenic disorders in this category of patients, and the assessment of the severity of the identified changes. Materials and methods. The work analyzed the data of 214 patients (169 men and 45 women) who were operated from 2008 to 2021 with a diagnosis of bladder cancer. Patients underwent RC with the formation of a hetero- or orthotopic ileoconduit. We analyzed the indicators of general urine analysis, biochemical blood test, bacteriological analysis of urine for flora, performed both before RC and in the late postoperative period. Also The results of ultrasound of the kidneys, bladder (reservoir), MSCT of the kidneys performed before RC and in the late postoperative period were studied. We selected 37 patients from the general group in random order, who prospectively underwent a biochemical blood test, a biochemical analysis of daily urine, and an assessment of the acid-base composition of venous blood. Statistical analysis was performed by calculating the relative risk, as well as calculating the t-test for independent groups using the computer program Statistica 10.0 (StatSoft USA). Results. Urinary stones of the upper urinary tract after RC, ortho- and heterotopic intestinal plastics of the bladder in the late postoperative period (more than 1 year) were diagnosed in 27 out of 214 patients (12.6%). The relative risk of urolithiasis in patients with pyelectasis before surgery is 3.87 times higher than in patients without changes in pelvicalyceal system at the preoperative stage (p=0.0004). In patients after RC with impaired renal function in stages III-V (GFR 60 ml/min (p=0.005). RC patients with a BMI >30 had a 2.431-fold higher risk of urinary stone formation than those with a BMI 7.0, diagnosed after surgical treatment (p=0.003). The relative risk of developing urolithiasis in patients with urine pH >7.0 detected before surgery is 4.85 (p<0.0001). There was a trend towards an increase in the number of urolithiasis cases in patients who underwent RC with bacteriuria diagnosed after surgery according to urine culture (in patients with identified Enterococcus spp., Enterobacter cloacae, Providencia rettgeri (p<0.05)) compared with patients in of which sterile urine was detected. In patients suffering from urolithiasis after undergoing RC, compared with the control group of patients in the biochemical analysis of blood, there is a statistically significant difference between the level of creatinine (p=0.033), a decrease in the level of GFR from 79.9 to 68.7 (p=0.046). There was a statistically significant increase in the pH level of the urine (p=0.0025), an increase in the level of oxalates in the daily urine (p=0.0035), a decrease in the concentration of uric acid (p= 0.039), calcium (p=0.024) in urolithiasis patients after RCE compared with patients in the control group in biochemical analysis of daily urine. Conclusion. The presence of an expansion of the pelvicalyceal system before surgery, the patient's BMI> 30, urine pH> 7.0 both before and after the operation, a decrease in the patient's GFR <60 ml / min and the presence of bacteriuria in the general analysis of urine after RC are the risk factors for the urolithiasis after RC, intestinal plasty of the bladder.