Comparison Of 24F Tract And 16F Tract Percutaneous Nephrolithotomy For The Treatment Of Renal Calculus

Forewords:Urinary tract calculus is the common disease of urology, of which the most universal primary lesion is from the kidney. Since first introduced in 1976, percutaneous nephrolithotomy (PCNL) for treatment of kidney calculus, which has less invasive, safe and the higher stone clearance rate, is widely promoted and applied in clinical practice to date. The main indications for this surgery are to deal with renal and the top of ureteral calculus. However, with the surgery carried out on a large number of clinical practice, various complications followed, and the most common were surgical bleeding and postoperative infection. The size of tract is one of the most important factors.The appropriate channel is a key step in the success of the surgery. Percutaneous renal access is currently divided into large channel (30F-36F), the standard channel (20F-24F)and mini-channel (11F-18F). Compared to the open surgery, the relatively large channel PCNL is the more mature and minimally invasive surgical techniques, but still has some invasive and traumatic, and postoperative serious complications still occurred, such as bleeding, potentially severe renal cortex injury and so on. With the progress of science and technology, some scholars has been further improved the large channel in order to reduce these complications,and the channel diameter was reduced to 20F-24F, namely, the standard channel, significantly reducing bleeding and the risk of renal damage. With the development of updated equipment, the mini-PCNL was introduced in the 1997,of which the channel was 11F-18F and it used smaller diameter mirror sheath and ureteroscopy for treatment of children with kidney calculus or smaller stones. The most common channel are mini-PCNL(11F-18F) and the standard channel (20F-24F) PCNL in our country. Two kinds of channel represents the different technical schools. Mini-PCNL(mPCNL) is a technique with Chinese characteristics, and some scholars think that a smaller caliber might have the potential advantages to reduce blood loss and renal parenchymal damage, but there is no literature to state it clearly. Part of prospective studies,which compared the surgery-induced acute renal tissue damage associated protein markers TNF-α, IL-1, IL-6, CRP, SAA between 2 groups, found that there were no significant difference. The mini-PCNL did not have to the advantage to reduce short-term or long-term renal parenchymal damage.In the stone clearance rate, different studies has reported the various results and there is no consensus on the view. This result is due to many factors.Currently,16F mini-PCNL is widely carried out in our country. But there are also a series of complications due to the passage of small caliber and the most common is the postoperative infection. It is necessary to use high-pressure infusion in order to maintain clear vision during operation, but a small diameter channel hinders liquid to outflow, resulting in higher pressures in renal collecting system.If the pressure exceeds a certain limit, the fluid will go into the blood perfusion retrograde. The canal contains renal tubule reflux, renal pelvis and sinus reflux, regurgitation perivascular,renal pelvis venous reflux and lymphatic reflux. The stone is the carrier of bacteria and bacterial endotoxin, particularly infectious renal stones. Stones were crushed by the gravel equipment and its internal bacteria or endotoxin immediately released into the urine. The high pressure promoted perfusion fluid into the bloodstream,leading to blood infection with the way.The accumulated certain extent, was to stimulate the body systemic inflammatory response syndrome. The body uncontrolled released inflammatory factors, such as IL-1, IL-6, PCT, CRP, TNF-a and so on. These inflammatory mediators damaged the body tissue or cells through a series of related reactions,then causing the urosepsis, severe septic shock or death. Foreign scholars reported that there was about 21.0%-32.1% patients fever >38℃ after PCNL. Although postoperative fever in most patients is transient, but there were still about 0.3% ～4.7% of patients progressed to the urosepsis. On the other hand, due to limitation of the smaller diameter channel, the mini-PCNL only can use the finer endoscopy or ureteroscopic,which significantly limites gravel instrument and most of the powder use holmium laser lithotripsy. Mini-PCNL will significantly extend the operation time to the same size stone than the standard channel PCNL. Prolonged operative time increases the risk of postoperative infection.Compared with the mini-PCNL, standard channel is expanded to 20F-24F, which fully absorbs the advantages of minimally invasive channel, offers broad vision and higher stone clearance rate. Combined with ultrasonic and pneumatic lithotripsy system (EMS), the stones were crushed as massive gravel, and the stone fragments <0.8 cm can be discharged smoothly or clipped out by the forceps. Owing to the large outer sheath,it is not prone to make the stone fragments clogging the outlet.The spacious channel, effectively reduces intrarenal pelvic pressure during operation. It is particularly suitable to process the diameter>2cm kidney stones or staghorn calculus. The larger stones, which usually have complex components, contain a significant amount of endotoxin or bacteria and they are sufficient to initiate infection after PCNL. The sensitive infection-related substances should be monitored, such as procalcitonin (PCT), and so on. At present, most domestic clinicians still select the mini-PCNL for treatment of kidney stones>2cm. There is no This surgical approach in terms of efficacy and safety whether this method is more excellent than the standard channel PCNL, there is no definitive conclusion and the further research should be done in the future. The previous researchs only explored a number of factors, which were relatively one-sided results, and the conclusions were inconsistent. Further research should be done to compare standard channel PCNL and mini-PCNL on the efficacy and safety. This result is useful for clinical diagnosis and treatment in order to make the surgery achieve better therapeutic effect.Obejctive:Clinical data of 83 patients with renal stone>2cm who accepted percutaneous nephrolithotomy in our department from April 2014 to July 2015 were collected. According to the size of the channel,they were divided into 24F channel group and 16F channel group. Comparing the efficacy and safety between 2 groups, it will provide evidences for the clinical treatment of kidney stones to select suitable percutaneous renal access.Methods:1. clinical data:Clinical data of 83 patients with renal stone>2cm who suffered percutaneous nephrolithotomy in the department of urology from April 2014 to July 2015 were collected and reviewed. The inclusion criteria involved:(1) those patients who had been diagnosed as renal stones for the diameter>2cm by intravenous urography,kidney ureter bladder,and abdominal CT. The stone located in ureteropelvic junction, renal pelvic or calyx; (2) The hydronephrosis is 2-5cm; (3)single, multiple or incomplete staghorn stones;(4) Previous ipsilateral kidney stones did not undergo surgery (percutaneous nephrolithotomy or open surgery);(5) No surgical contraindications. The exclusion criteria involved:(1) Congenital malformations of kidney(ureteropelvic junction obstruction congenital stenosis、 polycystic kidney disease、horseshoe kidney.etc.);(2) severe cardiopulmonary dysfunction,;The patients can not tolerate prone position;(3) Severe coagulation disorders;2. Acquisition Indicators:(1) preoperative general information:gge, sex, body mass index (BMI);(2) preoperative urinary tract infection;(3) Intravenous urography (IVP),abdominal plain film (KUB) or urinary tract CT definite characteristic parameters of the stone,including the side, the maximum diameter of the stone; single or multiple; degree of hydronephrosis.(4)The size of channe1:24F channel (It was established by balloon dilatation) or 16Fchannel (it was established by fascia dilator);(5) Gravel method:pneumatic lithotripsy or holmium laser;(6) Intraoperative lithotripsy time;(7)Intrarenal pelvic pressure;(8) Hemoglobin missing values;(9) One phase of stone clearance rate (a residual stone less than 4mm stone means stone cleanedclean);(10) The rate of postoperative fever (body temperature>37.5℃);(11) Procalcitonin content;(12)The rate of postoperative blood leukocyte count(>10* 109/L); (13) Incidence for the damage of other organ.3.Grouping:They were divided into 24F channel group and 16F channel group according to different size of channel.4. Statistical methods:We used SPSS20.0 software to process the related data. Normally distributed data were expressed as(X±s). The completely random analysis of variance was used to analyze measurement data. We used the LSD-t test to deal with pairwise comparisons between the measurement data. The x2 test was used to compare count data. Non-normal distribution of experimental data indicate the median, which was processed by Spearman correlation test or Mann-Whitney U test. The difference of P<0.05 was considered statistically significant.Results:1.The study included 83 patients。Among them,there were 52 men and 31 women, whose mean age was 50 years old (range from 23 years old to 75 years old). All of them were unilateral kidney stones. They were divided into 24F channel group of 40 patients and 16F channel group of 43 patients.There were no statistically significant difference about patients age, sex, preoperative urinary tract infection ratio, the side of stones, the maximum diameter of stones, stone location, degree of hydro nephrosis between 2 groups.2. All patients had the successful surgery. There were no serious complicationgs,such as intraoperative bleeding, damaged intestine, spleen, liver, diaphragm, pleura and other neighboring organs. Three patients lost the first channel in the 16F channel group. With the help of Doppler ultrasound,the surgeon repositioned to create a new channel to the target calyx successfully. The loss of channel did not occur in the 24F channel group channel. There were no statistically significant difference about hemoglobin missing values [(11.8±4.4) g/L,(13.7±4.7) g/L] and the stone clearance rate [87.5%(35/40),81.4%(35/43)] between 2 groups. The 24F channel PCNLand 16F channel PCNL had the statistically significant difference in intraoperative lithotripsy time [(12.8±3.7) min, (23.3±3.6) min)], intrarenal pelvic pressure [(22.5±4.3) mmHg,(34.6±4.1)mmHg], the rate of postoperative fever [17.5%(7/40),39.5%(17/43)],Procalcitonin content (>0.1ng/ml) [15.0%(6/40), 34.9%(15/43)],and the rate of postoperative blood leukocyte count(>10*109/L) [10.0%(4/40),27.9%(12/43)].3. One patient in each group appeared delayed bleeding. The bleeding in the 24F channel group stopped on their own by occlusion of the fistula and oppressing the fistula hole; The conservative treatment was ineffective for the patient in 16F channel group.Then the high selective renal artery embolization was underwent to block bleeding artery. Two groups of patients had no blood transfusion after surgery.4. Five patients with 24F channel group remained stones.Among them,two cases of the stones had been self-discharged after 3 weeks, and three cases did the extracorporeal shock wave lithotripsy after 3-4 weeks. Eight patients with 24F channel group remained stones. Among them,3 cases of the stones had been self-discharged after 3 weeks.;three cases did the extracorporeal shock wave lithotripsy after 3-4 weeks;Other cases did the second phase of percutaneous nephrolithotomy after 2-3 weeks and the residual stones were removed smoothly.Conclusions:The size of channel in percutaneous nephrolithotomy has the impact on the incidence of the stone clearance rate postoperative bleeding,infection and other complications.It is of great significance to select the appropriate channel for improving the safety and efficacy of percutaneous nephrolithotomy. Compared with the fascial dilator building 16F channel,the 24F channel established balloon dilatation has higher stone clearance rate, shorter operative time and less bleeding.The intrarenal pelvic pressure maintained low level and the stones were crushed under safe pressure.This method has the advantage of the low incidence of postoperative infection and the effect of surgery is obvious. It can be extended as the preferred channel for the treatment of kidney stones>2 cm or staghorn calculi.