Investigation Of Low-dose Ct Localization In Percutaneous Nephrolithotomy And Perioperative Changes Of Renal Function Of The Patients

[Background]Along with the improvements of helical CT performance and technology elevation, helical CT scan has been more widely used in clinical procedure. In recent years, due to the minimally invasive percutaneous nephrolithotomy technology promotion and application, hel ical CT has been widely used in PCN’L treatment in localizing scan pre-operation and postoperative follow-up, and being believed to be the standard imaging tool for percutaneous nephrolithotomy. With the wide application of helical CT, the ethical consideration about radiation increasing is raised. Thus, low-dose spiral CT scan is studied extensively in many areas, but mainly in diagnosis of renal colic in urology. During percutaneous nephrolithotomy treatment process, the focus of interest of urologists are mostly concentrated on the technique of X-ray protection, in order to reduce or avoid the radiation of the surgical staff, and little concern about the X-ray radiation for patients during perioperative period. The purpose of this study is to provide theoretical support for the low-dose unenhanced helical CT scan in diagnosis of upper urinary tract calculus, localization before MPCNL surgery as well as to reduce the peri operative radiation for patients and surgery staff.Section I Feasibility study of low-dose unenhanced helicalCT localization in minimally invasive percutaneous nephrolithiathis(MPCNL)[Objective]To probe the feasibility of unenhanced low-dose helicalCT localization for minimally invasive percutaneous nephrolithotomy (MPCNL) with comparison to standard-dose helicalCT, our aim is to reduce the radiation of helicalCT scan being used for patients suffered from upper urinary stone during diagnose and MPCNL localization.[Materials and Methods]28cases of upper urinary tract calculus who were admitted for MPCNL treatment underwent both localization scan, Low-dose CT and standard-dose CT were independently reviewed by two radiologists for the characterization of renal and ureteral calculi (location, size, distribution), Diatrizoate Meglumine(DTZ) coated fabric particle, perirenal adjacent organs (liver, splen, colon, lung or pleural membrane), blood vessels within renal sinus (anterior or posterior branch of renal blood vessels) and for indirect signs of renal or ureteral calculus (renal enlargement, pyeloureteral dilatation), simultaneously with the indexes of localization(percutaneous puncture angulation and depth) which would be used in MPCNL procedure and effective radiation of helical CT.[Results]In all the patients with a BMI<30or BMI≥30, in accordance with standard-dose CT, low-dose CT was100%coincident for depicting location of the renal and ureteral calculus, DTZ coated fabric particle, renal enlargement, pyeloureteral dilatation, adjacent organs and the presumptive puncture point with a96%coincident for blood vessels signs within renal sinus. The indexes of puncture depth, puncture angulation and maximum calculus ransverse diameter on axial surface showed no statistical variation between the two dose CT scan (P>0.05), and with a significant variation for calculus visualization slice number(P=0.026). The effective radiation of low-dose helical CT scan is significantly lower than that of standard-dose (0.88±0.10vs3.58±0.38, p=0.000)[Conclusion]Unenhanced low-dose CT achieves sensitivities and accuratissime same to those of standard-dose CT in assessing the localization of renal ureteral calculus, adjacent organs conditions, identifying the maximum calculus ransverse diameter on axial surface, percutaneous puncture depth and angulation in patients that would be treated by MPCNL, and can be used as first alternative localization method routinely with a significantly lower radiation of helical CT for patients. Section Ⅱ Investigation of clinical application of low-dose unenhanced helicalCT localization in MPCNL treatment for upper urinary calculi[Objective]To probe the clinical value of low-dose unenhanced helicalCT localization in MPCNL for upper urinary tract caculi treatment, and authenticate the feasibility of low-dose unenhanced helicalCT localization in advanced clinical application.[Material and methods]From October2010to September2011,78cases of patients suffered from upper urinary tract stones recruited to the study, all the patients were divided into two groups, low-dose helicalCT localizing group (low-dose group) and standard-dose helicalCT localizing group (standard-dose group), and undertook a conventional helical CT localization before MPCNL in a prone position to determine the puncture point, puncture angle and puncture depth. The effective radiation of CT scan in patients, number of puncture times, buildup time of percutaneous nephrolithotomy channel, intraoperative number of times of C-arm X-ray use, blood loss and residual stone rate were compared between the two group.[Results]No statistically significant difference (p>0.05) was found in the average number of puncture times, puncture angle and depth, channel buildup time, the number of times of C-arm use, blood loss and residual stone between the two groups. A statistically significant difference of effective radiation of helicalCT was found between the two groups (0.8882+0.0797vs3.5828±0.3086, p<0.001), with a ratio of1/4(24.79%) in low-dose group to standard-dose group. No adjacent organ injury occurred in two groups.[Conclusion]Low-dose helical CT localizing scan for minimally invasive percutaneous nephrolithotomy could be an alternative to the standard-dose helical CT localizing scan, be profit to helping reduce the perioperative radiation dose of X-ray for the patient and intraoperative C-arm applications, without increasing the risk of surgery and influence on the effect of surgical treatment. Section Ⅲ "target-domain" low-dose non-enhanced spiral CT scan positioning combined with intraoperative ultrasound-guided puncture the PCNL clinical research[Objective]To investigate the feasibility and clinical value of "target-domain" low-dose non-enhanced spiral CT localization joint ultrasound-guided puncture in MPCNL treatment, for further reduction the perioperative radiation.[Materials and Methods]Since November2011to March2012,43cases of upper urinary tract calculi patients undertook MPCNL treatment by a preoperational "target-domain" low-dose helical CT localization combined with intraoperative ultrasound-guided puncture, the low-dose helical CT group of section Ⅱ was contributed to the control group. The effective radiation of helical CT, number of puncture times, time of percutaneous nephrolithotomy channel establishment, blood loss, intraoperative C-arm X-ray application as well as residual stone rate were compared between the two groups.[Results]No statistically significant difference was found between "target-domain" low-dose group and low dose group in the average number of puncture times, puncture angle, puncture depth, channel buildup time, residual stone (p>0.05), the average blood loss in "target-domain" low-dose group was higher than that of in low-dose group with no significant difference (P=0.072), and the effective radiation in "target domain" low-dose spiral CT group is significantly lower than that of the low-dose group (0.6988±0.0418vs0.8882±0.0797, p0.001), with a ratio of80%in "target-domain" low-dose group to low-dose group, same with the intro-operative C-arm use (0.65±1.59vs1.46±2.26, p=0.015). No adjacent organ injury occurred in both groups.[Conclusion]"Target-domain" low-dose spiral CT localization combined with ultrasound-guided puncture, in MPCNL treatment for upper urinary tract stones, can help to further reduction of the patient’s radiation exposure, and simplify ultrasound-guided steps with reduction of intraoperative C-arm X-ray palliation and contribute to the radiological protection for the surgical staff. [Background]Urinary stone is common and frequently-occurring disease in urinary system, the incidence of urinary calculi rises in recent years. The etiology of urinary stones is complex and ingredients is diverse, with high morbidity and recurrence rate, to prevent the recurrence after treatment of stones is an important part of the treatment for urinary calculi. And it is of considerable significance to identify etiological factor, direct stone treatment and prevent stone recurrence. The calculus component analysis includs infrared stones spectroscopy and chemical qualitative analysis commonly used in clinic, for the two methods, obtained specimens of stone removed through extracorporeal lithotripsy or surgical treatment are required. If the stone composition can be identified before treatment, it will no doubt play a guided role in good choice of stone treatment. And how to learn the stone composition before treatment has been constantly concerned for urology colleagues in recent years. With the extensive application of spiral CT, the CT values of different stone ingredients has been found, and the investigations about the use of CT value to determine stone composition proceeded, with an concentration on only standard-dose helical CT scan for composition analysis. The application of low-dose CT scan in stone CT value determination, simultaneously both with physical and chemical analysis methods to determine the stone composition and the relationship between the composition and CT value have not been reported.Section I The in vitro empirical study of probability for un-enhanced low-dose CT scan in composition analysis of urinary calculus[Objective]To investigate the feasibility of low-dose helical CT scan in composition analysis of urinary calculi in vitro.[Materials and Methods]50stones removed from upper urinary tract by operation were studied in vitro with standard-dose(120Kv/100mAs) and low-dose(120Kv/25mAs) spiral CT scan for determination of CT value (Hu), and infrared spectroscopy and chemical analysis methods were undertaken simultaneously for determination of chemical composition of the stones for comparison.38stones in conincident ingredient was studied.[Results]1. Comparison of low-dose and standard-dose spiral CT scan in CT values and noise of the stonesNo statistically significant difference was found in CT value(1258.44±454.24vs1293.57±454.24, n=38,p=0.218) and noise (236.16±162.58vs266.42±183.21,p=0.284) of stones between low-dose group and standard-dose group.2. Comparison of stone compositions by infrared spectroscopy and chemical analysisThe total coincidence rate of all the stones was86.36%(38/44), with a coincidence rate of77.27%(34/44) for calcium stones measured by infrared spectroscopy and chemical characterization method, no statistically significant difference was found(P=0.398); and for all the38stones with coincident compositions, the coincidence rate of calcium stones89.5%(34/38).3. Analysis of relationship between the spiral CT value and composition of the stones.With the two analysis methods, stone composition obtained show that calcium oxalate stones was the main stone ingredient. For the pure ingredients stones, the pure calcium oxalate stones had the highest CT density, while the lowest CT values is of uric acid stones and could be distinguished by CT value between the two ingredients stones, CT values of other mixed stones ranged between calcium oxalate and uric acid stones.[Conclusion]Chemical analysis and infrared spectroscopy can meet the need for clinical stones component analysis, and low-dose spiral CT scanning can replace the standard dose helical CT for the preliminary composition analysis and determination of density in vitro. Section Ⅱ The clinical investigation of probability for un-enhanced low-dose CT scan in predicting composition of ur inary calculus[Objective] Investigate the feasibility of low-dose spiral CT scan predicting stone composition in vivo[Materials and Methods]52cases of upper urinary stone patients underwent a standard-dose helical CT scan and a low-dose helical CT scan for CT value measurements since April2010to April2011, of which,27cases underwent MPCNL treatment and stone composition analysis, the relationship between stone composition and CT value was analyzed.[Results]1. Comparison of stones CT value and noise measured by low-dose and standard-dose helical CT in vivo.By the52patients with hel ical CT scan, no statistically significant difference was found in the stone CT value between low-dose and standard-dose helical CT scan group (986.80+302.31vs986.60±311.51, p<0.05), but the standard devi at ion (noise) of the CT values showed statistically significant difference between the two groups.(145.40±98,77vs117.54±82.73, p<0.001).2. The relationship between stone CT value and stone composition of the27cases in vivo27patients body stone composition analysis showed that pure calcium oxalate stones, pure urine ammonium ingredients stones in1patient each, while the remainder were of mixed stone composition. By determination, the CT value of calcium oxalate stones+calcium phosphate, pure calcium oxalate and urinary ammonium stone were more than1000Hu, the lowest CT value of1case of no ingredients stones is422.07Hu, and the rests of the stones in the CT values were between the stones of the above ingredients and mutual cross, no statistically significant difference of the same ingredients stone was found between low-dose and standard^dose CT value (p>0.05) 3. Comparison of homogeneous stones (calcium oxalate) in vivo and in vitro CT values and noiseThe CT value of16calcium oxalate stones in vivo was lower than that of12calcium oxalate stones in vitro in both dose of CT scan without statistically significant difference(p>0.05), but significantly different for standard deviation of CT value (149.98+76.94vs268.62±149.98in low-dose group, and114.72±69.25vs288.33±197.95in stansard-dose group, p<0.05)[Conclusion]Low-dose helical CT scan can replace standard-dose helical CT scan in CT value determination of stone and preliminary analysis for stone composition in vivo, it should be careful to determine stone composition in vivo by CT value of stone measured in vitro. [Background]Urinary calculi is a global disease, the stones incidence present an upward trend in recent years with the improvement of living conditions and diet changes. Currently, minimally invasive treatment is the main choice for urinary stone treatments, the minimally invasive percutaneous nephrolithotomy lithotripsy treatment of urinary stones in our country has been widely carried out and applied recent years, and has become one of the preferred treatment method to replace the traditional open surgery. Minimally invasive percutaneous nephrolithotomy lithotripsy is divided into micro-channel, standard channel and big channel according to the channel size, and single channel, dual and multi-channel according to the number of channels, of which will no doubt bring varying degrees of damage to the patient, whatever its purpose is to remove stones cleanly, reduce the rate of residual stone. The influence of PCNL on renal function as well as patient body status has been reported, but the parameters in observations are limited to serum creat inine, blood urea ni trogen and GFR. The dynamic changes of the peri operative blood sensitive indicators for renal function, such as β2MG, CYS-C, as well as emergency indicator related factors of CRP have not been reported.[Objective]To investigate the dynamic changes and clinical significance of β2MG, CYS-C being as renal function blood indicators, and blood acute phase response protein CRP early after MPCNL treatment.[Materials and Methods]From April2010to April2011,31patients with upper urinary tract stones in our hospital were studied by monitoring the dynamic changes of serum creatinine, blood urea nitrogen, UA,β2MG, CYS-C and CRP, pre-operation, Id and3d post-operation of MPCNL, and the preoperative urine WBC level, operative time, blood loss and body temperature changes were analyzed in relationship simultaneously.[Results]1. The blood WBC, neutrophil ratio and Bun, Cr, UA,β2MG CYS-C and CRP changes of patients for MPCNL treatment.With blood biochemistry check, postoperative blood WBC, blood neutral granulocyte ratio, serum Cr rose Id after surgery (p<0.01), and then dropped back, but blood UA, serum β2MG decreased after surgery (p<0.05and0.01), and blood CRP after surgery increased significantly (p<0.01), and no significant changes for serum BUN and cystatin-C pre-and post-operation (p>0.05).2. Correlation analysis between CRP and each indicator in patients with MPCNLBy correlation analysis, the preoperative blood CRP changes with urine leukocyte levels were significantly positively correlated (r0.703, p=0.000), blood CRP of Id post-operation were significantly positively correlated with preoperative urine WBC (r=0.447, p=0.012), blood WBC (r=0.540, p=0.002), blood β2MG (r＝0.376, p=0.042) and body temperature changes (r=0.496, p=0.005) was significant with a positive correlation, while the postoperative blood CRP level3d post-operation is only significantly positive correlated to the operative time (r=0.325, p=0.001), no obvious correlation with other indicators.[Conclusion]As far as renal renal function be concerned, MPNCL is a safe surgical modality with smaller potential hazards and impacts on renal function. CRP is a comprehensive indicator of stress response, the CRP monitoring after MPCNL can be used to understand the state of the patient’s body, being superior to the monitoring of blood WBC and neutrophil levels.