Study On The Mechanism Of Urosepsis Following Percutaneous Nephrolithotomy

Purpose: 1.To investigate the risk factors of urosepsis following percutaneous nephrolithotomy(PNL)so as to provide a theoretical basis for the prognosis of urosepsis after PNL.2.To investigate the function of HMGB1/TLR4 signal pathway in inflammatory response following PNL by irrigating with HMGB1 netutralizing antibody or recombinant HMGB1 administered perfusion solution and testify that HMGB1 regulated the inflammatory response by activating TLR4 signal pathway.3.To establish high-pressure intrapelvic perfusion pig model and investigate the effects of various flow rate and verapamil concentration gradients on intrapelvic pressure and systemic side effects.Materials and method: 1.293 patients fulfilled the inclusion criteria were enrolled in this investigation.Patients were distributed to two groups according to the presence of a post-operative SIRS.Parameters such as age,sex,presence of diabetes mellitus,hypertension,preoperative fever,previous lithotripsy of the ipsilateral side,levels of hydronephrosis,stone size and preoperative laboratory examinations such as white blood cell count,neutrophil granulocyte ratio,creatinine,serum levels of C-reactive protein,procalcitonin and interleukin-6,operation time and presence of residual stones were compared between groups.2.Intrapelvic perfusion was performed with saline or perfusion solution administered by HMGB1 netutralizing antibody or recombinant HMGB1 respectively under perfusion pressure of 150 mm Hg in intrapelvic perfusion pig models for 30 mins.m RNA expressions of HMGB1 and TLR4 in the kidney were measured by q RT-PCR.Protein expression of HMGB1 in the kidney was measured by western blot or immunoprecipitation.Inflammatory cytokines were collected and detected by ELISA.3.We established high-pressure intrapelvic perfusion pig model by intrapelvic perfusion performed with various flow rate gradients(0,2,4,6,8,10,14,20ml/min)and different concentrations of verapamil(0,0.1,1,10,100ug/ml)and investigated the dynamic changes of intrapelvic pressure.Results: 1.Of total 293 patients undergoing PNL,84 patients were found the presence of post-operative SIRS.Univariate analysis revealed that female gender(p=0.028),presence of preoperative fever(p<0.001),previous lithotripsy of the ipsilateral side(p=0.029),large stone size(p<0.001),positive preoperative urine culture(p=0.041),the presence of leucocyturia(p=0.007),elevated serum levels of C-reactive protein(p=0.011)and procalcitonin(p<0.001),long operation time(p=0.044)and presence of residual stones(p=0.029)were risk factors for potential urosepsis following PNL,while preoperative fever(p<0.001),large stone size(p<0.001)and elevated serum levels of procalcitonin(p=0.024)were independent risk factors for potential urosepsis following PNL.2.Expression levels of m RNA and protein of HMGB1 increased following high pressure renal pelvic perfusion,together with elevated expression of m RNA of TLR4.Inhibition of HMGB1 attenuated the serum levels of inflammatory cytokines and infiltration of neutrophils and macrophages stimulated by high-pressure intrapelvic perfusion.And the administration of r HMGB1 stimulated the production of inflammatory cytokines and infiltration of neutrophils and macrophages.In addition,inhibition of HMGB1 down-regulated the expression of TLR4/My D88 signal pathway,whereas administration of r HMGB1 up-regulated the expression of TLR4/My D88 signal pathway.3.Intrapelvic perfusion with 1,10 and 100 ug/ml verapamil could reduce theelevation of intrapelvic pressure with no effects on blood pressure and heart rate,whereas intrapelvic perfusion with 0.1 ug/ml verapamil failed to reduce the elevation of intrapelvic pressure.Conclusions: 1.Results of this research suggest that the presence of preoperative fever,large stone size and the elevated serum levels of procalcitonin were independent risk factors for potential urosepsis following PNL.2.HMGB1/TLR4 signal pathway plays an important role in inflammatory response following PNL.3.Intrapelvic perfusion with verapamil could reduce the elevation of intrapelvic pressure significantly with no systemic side effects.