| Background:Urinary stone is a common disorder of urology, the prevalence of urolithiasis is 5%～10% in developed countries. The prevalence of urolithiasis(1%～5%) is slightly lower in China compared with foreign country, but which is higher in some provinces of southern China. Following the rapid economic development and improvement of nutitional condition, the location of urolithiasis is different from the past, the prevalence of upper urinary calculi was increased, the prevalence of lower urinary calculi was decreased. Urolithiasis usually cause infection and obstuction, and eventually lead to loss of renal function. Therefore, urolithiasis has become one of the main diseases that endangered human health.With the advance of medical equipment and improvement of endoscopic techniques, urological surgery has entered the era of minimally invasive surgery, and traditional open surgery decreased rapidly, minimally invasive surgery has become a main way for the treatment of urinary calculi in place of open surgery. For kidney calculi and upper ureteral calculi, percutaneous nephrolithotomy has become the main way of treatment.Percutaneous nephrolithotomy is minimally invasive and effective character, but in clinical practice, inevitably the procedure is associated with complications that can cause a certain degree of influence to patients’health. According to literature, the complication rates associated with percutaneous nephrolithotomy have been reported to range from 5% to 18%. In the percutaneous nephrolithotomy study by Nahas and coworkers,240 cases were retrospectively analyzed, a higher incidence of complications was found, the complication rate was 27%, bleeding was common complication,16% of the patients required a blood transfusion,5 cases were treated with hyperselective renal artery embolus therapy because of severe bleeding.In order to reduce bleeding associated with percutaneous nephrolithotomy, people have been exploring the risk factors. According to previous studies, bleeding with percutaneous nephrolithotomy is associated with a variety of factors, divided into preoperative factors, intraoperative and postoperative factors.Because diabetes can cause renal atherosclerosis and microangiopathies, diabetic patients are more prone to bleeding if they undergo percutaneous nephrolithotomy. Earlier studies suggested that women were prone to urinary tract infection, so surgery was more prone to bleeding, but other scholars did not identify with this viewpoint. In the previous study, the size of stone was a risk factor for bleeding associated with percutaneous nephrolithotomy. The location of stone has been proved to be risk factor for bleeding associated with percutaneous nephrolithotomy by many scholars. Turna et al that the location of stone affected greatly bleeding in percutaneous nephrolithotomy, and emphasized that incomplete or complete staghorn calculi was a high-risk factor for hemorrhage.There are many clinical studies on the access of percutaneous nephrolithotomy lithotomy. Although clinical comparison research about single access and multiple access. Aron drew the conclusion:multiple access was safe and effective, and would not lead to more complications. But some scholars believed that, with the increase of puncture access, the possibility of renal and adjacent organs injury would increase, the amount of bleeding also increased.After open surgery, kidney is relatively fixed, so range of motion is reduced. Calyceal neck may be lacerated easily, and lead to bleeding, so open surgery is a high-risk factor for hemorrhage associated with percutaneous nephrolithotomy. It is generally believed that severe bleeding is prone to occur due to thick cortex with no hydronephrosis and mild hydronephrosis.The use of minimally invisive percutaneous nephrolithotomy, however, can decrease the likelihood of bleeding.A great number of bleeding associated with percutaneous nephrolithotomy can be managed by conservative treatment maneuvers, such as blood transfusion, positioning a nephrostomy catheter or electrocauterization, but there are still 1% bleeding requiring selective renal arterial angiography and embolization, or open surgical exploration, even partial nephrectomy or nephrectomy. Although these maneuvers can control the bleeding, which may cause transfusion reactions, spread of disease, the increasing cost of treatment and loss of renal function. Therefore, how to choose the optimal puncture point and avoid renal vessel, is the key to prevent hemorrhage associated with percutaneous nephrolithotomy.Chapter l:The analysis of risk factors for hemorrhage associated with percutaneous nephrolithotomyObjective:Although percutaneous nephrolithotomy has been accepted as a standard method for the management of large renal stones, the incidence of renal hemorrhage is relatively high. This study investigate the risk factors that affect bleeding during percutaneous nephrolithotomy, in order to prevent the occurrence of hemorrhage and improve the effect of surgery.Methods:The data of 396 cases who received percutaneous nephrolithotomy for upper urinary ract stone between May 2012 and August 2015 were retrospectively analyzed. Of 396 cases, there were 191 males and 205 females; The mean age was 42.5±13.1years (range 12-73); 186 right kidney stones,210 left kidney stones; including 83 staghorn stones,145 renal pelvis stones,110 renal calyceal stones, and 58 upper ureteral caculi.Statistical analysis was performed by using the SPSS ver.17.0 (IBM Co., Armonk, NY, USA), a p-value of< 0.05 (two-tailed) was considered statistically significant difference. Descriptive analysis was performed to evaluate distribution patterns of patient demographic, stone characteristics and operation finding, such as age, body mass index, stone size, operation time, drop in hemoglobin, etc. Percentage analysis was performed to evaluate stone location, degree of hydronephrosis, number of accesses, puncture guidance, comorbidity (diabetes mellitus and hypertension) and history of previous surgery.In order to clarify the risk factors for bleeding during percutaneous nephrolithotomy, groups were diverged based on median decrease in hemoglobin, and univariate analysis was performed to calculate the potential factors. Student t test was used to compare significane of change in continuous variabes, such as age, body mass index, stone size, operation time, decrease in hemoglobin, etc. Categorical data were compared with the Chi-square test for proportions. Independent variables were selected to enter the multivariate logistic regression analysis, according to the above Student t test and Chi-square test results, previous studies, as well as clincial experience. The Entry was set at 0.10. In order to determine the independence of the various factors, we finally selected stone size, staghorn stone, degree of hydronephrosis and and operation time, multivariate logistic regression analysis was used to clarify the risk factors for bleeding during percutaneous nephrolithotomy.Results:396 patients were successfully treated with percutaneous nephrolithotomy. According to decrease in hemoglobin (2.19+0.56, median 2.23), patients were divided into two groups:lesser bleeding (group 1) and higher bleeding (group 2). Two groups of Significant difference was found between the two groups in decrease in hemoglobin (1.780.39+vs.2.60+0.37, t=-21.5, P< 0.001).The age of Group 1 was 42.3+13.4 years and that of Group 2 was 42.7+12.8 years, with no significant difference between the two groups(t=-0.372, P= 0.710); The difference was not statistically significant in terms of gender between the two groups(x2=3.651, p=0.56); Group 1 included 98 left kidney stones and 100 right kidney stones, and Group 2 included 112 left kidney stones and 86 right kidney stones, no significant difference was found between the two groups (χ2=1.987, p =0.159).The mean stone size was 504.7±185.6 mm2 in Group 1 and 734±285.6mm2 in Group 2, respectively, indicating a significantly larger stone size in Group 2(t=9.476, p< 0.001). Group 2 included 61 staghorn stones, and Group 1 included 22 staghorn stones, thus, there were more staghorn stones in Group 2, significant difference was found between the two groups (x2=38.9, p< 0.001). A total of 97 cases was guided by ultrasound-guidance, and 101 cases by fluoroscopic-guidance in Group 1, a total of 89 cases was guided by ultrasound-guidance and 109 cases by fluoroscopic-guidance in Group2, no significant difference was found between the two groups (χ2=0.649, p=0.421).The mean operation time was 66.7±17.5 min in Group 2 and 61.2±20.9 min in Group 1, significant difference was found between the two groups (t=-2.812, p= 0.005). As for preoperative hydronephrosis, Group 1 had significantly more hydronephrosis of at least a moderate degree (x2=65.45, p< 0.001). According to the distribution of calculi, A total of 51 patients was treated with multiple-access procedures in Group 1 and 68 patients in Group 2, no significant difference was found in number of access between the two groups (x2=3.472, p= 0.062).13 cases were treated by open surgery in Group 1,10 cases in Group 2, no significant difference was found between the two groups (x2=0.415, p= 0.519). There was not significant difference in the previous history of percutaneous nephrolithotomy between the two groups (χ2=1.182, p= 0.277). Although a history of ipsilateral ESWL was present in 26 (13.1%) and 30 (15.2%) patients, respectively, but between the two groups no significant difference (χ2=0.333, p= 0.564). There were 33 patients with diabetes mellitus in Group 1 and 23 patients in Group 2, but no significant difference was found between the two groups(x2=2.08, p= 0.149). Also, no statistically significant difference was found in hypertension between the two groups(x2=0.925, p= 0.336).The above univariate analysis demonstrate the potential risk factors for bleeding during percutaneous nephrolithotomy, including stone size(P< 0.001), stone location(P< 0.001), operative time (P= 0.005) and degree of hydronephrosis (P< 0.001); According to the previous studies, reports in the literature, as well as clincial experience, in order to determine the independence of the various factors, we finally selected stone size, staghorn stone, degree of hydronephrosis and operation time, multivariate logistic regression analysis was used to clarify the risk factors for bleeding during percutaneous nephrolithotomy. Through logistic regression analysis, selected four variables were influence factors:stone size(B=0.975, Wals=28.766, P< 0.001, OR=2.652,95%CI:1.857-3.788), staghorn stone (B=0.378, Wals=7.092, P= 0.008, or= 1.459,95% CI:1.105-1.926), operation time(B=0.676, Wals=6.177, P= 0.013, OR=1.965,95%CI:1.154-3.348), and degree of hydronephrosis (B=-1.366, Wals=45.749, P< 0.001, OR=0.255,95%CI:0.172-0.379).Conclusion:Percutaneous nephrolithotomy was a well established technique in the treatment of upper urinary tract calculi, with effective and few complications, so it is a safe and effective method for the treatment of upper urinary tract calculi. There were many potential influence factors for bleeding during percutaneous nephrolithotomy, including stone size, staghorn stone, operation time, and degree of hydronephrosis.Chapter 2:The accuracy of computed tomography angiographyin the preoperative evaluation of renal vascular anatomyObjective:To investigate the accuracy of computed tomography angiography in the preoperative evaluation of renal vascular anatomy.Methods:From May 2013 to July 2015, a total of 42 patients with renal cell carcinoma who had undergone radical nephrectomy were enrolled in this study, computed tomography angiography(CTA) was preoperatively performed. Renal arterial anatomy were evaluated with computed tomography angiography by two radiologistes individually who were blinded to this study. For each patient, the surgeon documented surgical findings, including the number and branching patterns of renal artery, and accessory artery. Surgical findings were compared with CTA findings.The data of patient demographics and tumor characteristics were documented, including name, age, gender, body mass index, tumour location and size, histology and the number of renal artery. Descriptive analysis was performed to evaluate age, body mass index, and tumour size. Percentage analysis was performed to evaluate gender, tumour location, histology and the number of renal arteries. Categorical data were compared with the Chi-square test, such as the number of renal arteries. Statistical analysis was performed by using the SPSS ver.17.0 (IBM Co., Armonk, NY, USA), a p-value of< 0.05 (two-tailed) was considered statistically significant difference.Results:Forty-two patients successfully underwent radical nephrectomy, including 25 left radical nephrectomy and 17 right radical nephrectomy, no complications occurred. Among 42 cases,36 cases with single renal artery were observed by surgeons, and 6 cases with two renal arteries.Computed tomography angiography was performed in forty-two patients, provided a good map of renal arteries, the postprocessing images of 42 patients were displayed well, the renal vascular anatomical structure were displayed accurately. Combining with the original axial images, the renal vascular can located accurately. Combining with rotating and cutting technology, the renal vascular anatomical structure can clearly observed from different angles, including origin, morphology and distribution.The qualities of renal vascular reconstruction image were evaluated by two radiologists, including 2 points in 1 case,3 points in 1 case,4 points in 25 cases,5 points in 15 cases. Renal artery reconstruction images were effective in 40 cases, the qualities of 2 renal vascular reconstruction images were poor because of scan time, the accuracy of CT renal angiography was 95.2%.By observing renal vascular 3D images from different angles,37 cases with single renal artery were observed preoperatively, and 5 cases with two renal arteries, no statistical difference was found between CTA findings and surgical findings (χ=0.105,P=0.746).11 cases with 4 renal segmenta arteries were preoperatively observed on CT angiography images, and 3 leases with 5 renal arteries. Accuracy of CT angiography to detect renal segmenta artery was 95.2%, statistical results revealed there was no statistical difference between CTA and LPN findings for the number of renal segmenta artery (χ2=0.263, P=0.608).Conclusion:CT angiography is performed by simple and quick CTviewer postprocessing software, can provide a good map of renal vessels. Combining with the rotary cutting technology, the renal vessel can be observed from different angles on CT angiography images. CT angiography could display the anatomy and variation of renal vessel, and describe accurately the renal vascular anatomy structure. Therefore, CT angiography can be used as an important imaging method for the preoperative evaluation of renal vascular anatomy.Chapter 3:The Value of CT angiography assisting precise positioning in preventing hemorrhage associated with percutaneous nephrolithotomy:a prospective randomized studyObjective:To evaluate the clinical value of computed tomography angiography in reducing the risk of hemorrhage associated with percutaneous nephrolithotomy.Methods:From February 2013 to July 2015, a total of 185 patients with upper urinary tract calculi who had undergone percutaneous nephrolithotomy was enrolled in this study. The patients were randomly divided into two groups:experimental group and control group. The experimental group:92 patients preoperatively underwent ultrasonography, intravenous urography (IVU) and computed tomography angiography. The control group:93 patients preoperatively underwent ultrasonography, intravenous urography and non-contrast CT.In the control group, the urologist selected access site(s) and performed the puncture by intravenous urography and non-contrast CT. In the experimental group, before the procedure, intravenous urography and CT angiography were analyzed carefully by surgeons who obtained the renal vasculature maps and the distribution ofstones. The selection of an access site far away from larger vessels was performed by urologist, the urologist performed the puncture in view of the selected access site(s), and performed percutaneous nephrolithotomy.Statistical analysis was performed by using the SPSS ver.17.0 (IBM Co., Armonk, NY, USA), a p-value of< 0.05 (two -tailed) was considered statistically significant difference. Continuous variables were compared using Student t test, including age, body mass index, stone size (diameter), operation time, drop in hemoglobin and hospital stay. Nominal variables were compared with the Chi-square test, including gender, stone location, degree of hydronephrosis, number of access, stone-free rate and blood transfusion rate.Results:185 patients successfully underwent percutaneous nephrolithotomy. The mean operation time was 76.1±27.8 min in the experimental group and 77.6±23.0 min in the control group, no significant difference was found between the two groups (p= 0.454). There was not significant difference in stone-free rate between the two groups (89.1% vs.88.2%,P=0.98).The mean hospital stay were 8.2±1.8 days in the experimental group and 8.3±1.5 days in the control group, no significant difference was found between the two groups (p=0.428). There was not significant difference in the number of access between the two groups (1.3±0.6 vs.1.2±0.8, P=0.186).The blood loss(drop in hemoglobin) were 1.96±0.56 g/dl in the experimental group and 2.22±0.75 g/dl in the control group, significant difference was found between the two groups (p= 0.009). The blood transfusion rate(9.7%) in the control group was higher than that of experimental group(2.2%), significant difference was found between the two groups (p= 0.03). In the control group,1 patient developed a renal arteriovenous fistula and required renal arterial embolization, no patients developed a renal arteriovenous fistula or required renal arterial embolization postoperatively in experimental group, there were no significant diference in arteriovenous fistula and selective renal arterial embolization in the two group(0 vs.l, P=0.319;0vs.1,P=0.319).Conclusion:Prevention should be put first place for hemorhage during percutaneous nephrolithotomy. Renal CT angiography can accurately display renal vascular distribution, facilitate the identification of percutaneous puncture, reduce the incidence of bleeding during percutaneous nephrolithotomy, and improve the success rate of surgery. |
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