The Applied Research Of Tubeless Percutaneous Nephrolithotomy With A Externalized Ureteral Catheter

BackgroundBased on its excellent outcomes and acceptable low morbidity, Percutaneous nephrolithotomy(PCNL) is considered the treatment of choice for complex renal or impacted upper ureteral calculi over the last30years, since Fernstro’m and Johansson first described it in1976. Placement of a percutaneous nephrostomy tube for drainage has been an integral part of the standard percutaneous nephrolithotomy (PCNL) procedure. Previously it was thought that nephrostomy tubes provide hemostasis along the tract, avoid urinary extravasation, and maintain adequate drainage of the kidney. Placement of nephrostomy tubes may increase postoperative pain, analgesia requirement, and hospital stay. In recent years,’Mini percutaneous nephrolithotomy’(’mini-perc’) and Tubeless PCNL’ have been introduced with the aim to decrease the morbidity of this already established procedure.Micro-channel percutaneous nephrolithotomy (mPCNL) was first described by Jackman and associates for the application of PCNL to infants. Its use in adults has been subsequently described by several groups. They reported that the small tract significantly decreased the bleeding risk of traditional PCNL, but its indication was limited since the small percutaneous working sheath may increase the operating time. On this basis, Li X et al. modified the technique through a variety of ways,including preferring mainly posterior middle calyx access to inferior calyx access, using a specially designed nephroscope via the16F to20F tract,and using a pulse perfusion pump to flush out the stone fragments helped to shorten the operative time. Zhong W et al. also confirmed that intrapelvic pressure was lower than the level needed for a backflow(30mmHg) during mPCNL procedures. During the last10years, more than10,000mPCNL procedures performed to manage all kinds of upper urinary tract calculi were reported. The safety and efficacy of mPCNL have also been confirmed by recent reports. Furthermore, mPCNL has significantly lower incidence of bleeding necessitating transfusion in comparison with the standard PCNLIt may be interesting to note that the idea of ’tubeless’ existed even in the early years of evolution of PCNL. In1984, Wickham published the results of100patients in which no internal or external drainage tubes were used at the conclusion of case. Authors stated that with this approach, patients could leave the hospital within24h and the procedure was safe and efficient with a shorter hospital stay. However, subsequently Winfield et al. reported two patients with complications of premature nephrostomy-tube removal after the extraction of simple upper-tract calculi, who experienced serious hemorrhage and marked urinary extravasation necessitating transfusion, internal stenting, and prolonged hospitalization. They recommended that nephrostomy tube drainage should be provided during the first24to48h after percutaneous stone extraction, which subsequently became the standard practice for PCNL worldwide. However, in recent years, the procedure has been modified to what has been called ’tubeless’ PCNL, in which nephrostomy tube is replaced with internal drainage provided by a double-J stent or a ureteral catheter. More and more cases of tubeless PCNL were reported.Not all cases are suitable for being performed tubeless PCNL.There are no widely acknowledged selection criteria for tubeless PCNL. In general, the selection criteria for tubeless PCNL include stone burden<3cm, a single access tract, no significant residual stones, no significant perforations, minimal bleeding, and no requirement for a secondary percutaneous procedure. However, in recent years, the tubeless technique has been applied for the treatment of multiple stones, branching and complex stones, staghorn stones, concurrent UPJ obstruction, and collecting systems with various degrees of hydronephrosis. The technique has been successful in obese patients, children, and patients with recurrent stones after open surgery.The general consensus is that the tubeless approach is feasible only in a selected population that generally excludes cases of significant intraoperative bleeding, or situations with a likelihood of residual stone fragments,or situations with intensive renal pelvic or calyx injuries. Some cases is not indicated for tubeless PCNL, such as uncontrolled urinary infection, with histories of open urinary calculi operations or ESWL, concurrent congenital urinary tract anomaly, renal insufficiency, solitary kidney, intraoperative complications (perforation or bleeding), operating time more than2hours, severe urinary obstruction (ureteral stenosis or severe benign prostatic hyperplasia), oral anticoagulating agents, and multiple tracts.Literature has reported many types of tubeless PCNL. In the literature, tubeless PCNL studies are reported but only a few are totally tubeless PCNL. There are no discomforts of tubes and stents in those cases. These studies favor the suggestion that the best available drainage of the kidney is the normal peristalting ureter. However, this approach has not formed universal acceptability due to the concerns relating to the obstruction of ureter due to clots or stone fragments. Most authors seem to favor some kind of internal drainage in tubeless procedures. The most common type is tubeless PCNL with a double-J stent. It is suitable for those cases with residual stones after PCNL or upper urinary tract obstruction. One major disadvantage of tubeless PCNL with double-J stent is the need for postoperative cystoscopy to remove the stent. Another type is tubeless PCNL with a Tether. Bellman et al. suggested the placing of a7F/3F tailed stent with an attached string exiting the urethral meatus, which can be used to pull the stent out afterward in office setting to avoid the need of cystoscopy. However this procedure has the disadvantage that some patients may remove their stents prematurely by inadvertently pulling on the tether. Additional variations of the tubeless procedures have been described. Mouracade et al. prospectively analyzed the outcomes of tubeless PCNLs using two different stenting techniques, externalized ureteral catheter versus double-J stent placement. They concluded that externalized ureteral catheter is as feasible as a double-J stent. Moreover, stent-related discomfort and the need for postoperative cystoscopy to remove the double-J stent can be avoided with an externalized ureteral catheter. However, they suggested that in patients who are not completely stone-free at the end of the procedure, use of a double-J stent may be more beneficial as it may help in spontaneous passage of small residual fragments.The mechanisms between the externalized ureteral stent and the double-J stent may be different. Fine et al. reported fluoroscopic observations and drainage mechanisms of double-J stent. The urine from the bladder refluxed from the inner chamber of the stent to the renal pelvic. The refluxed urine in the renal pelvis triggered the peristalsis of the ureter. The vesicoureteric reflux and elevated renal pelvic pressure existed in the patients with double-J stent. Hower, the end of the external ureteral stent is in vitro. The vesicoureteric reflux may be slight and the renal pelvic pressure may be low in the patients with externalized ureteral stent.Only a few literature compared tubeless PCNL with standard PCNL.So far, there are no literature to study micro-channel tubeless PCNL.In order to investigate the the safety and efficacy of micro-channel tubeless PCNL with a externalized ureteral catheter, we initiated this projects. This projects include a retrospective study, a prospective study and a experimental research. The retrospective study will investigate the effectiveness and safety of micro-channel tubeless PCNL with an externalized ureteral catheter. The prospective study will investigate the differences between an externalized ureteral catheter and and double-J stent in micro-channel tubeless PCNl. The experimental research will investigate the differences of renal pelvic pressure in experimental white rabbits between indwelling a externalized ureteral catheter and a double-J stent.Section Ⅰ Safty and efficacy of micro-channel tubeless percutaneous nephrolithotomy with a externalized ureteral catheter:a retrospective studyObjective To review the safety and efficacy of micro-channel tubeless percutaneous nephrolithotomy (tubeless PCNL) with a externalized ureteral catheter.Methods From May2010to Dec2012,101patients (53males and48femals,mean age of47.5years) of renal or proximal ureteral calculi treated by micro-channel tubeless PCNL with a ureteral catheter were reviewed. The calculi were in right side in54patients, in the left side in46, and in the bilateral sides in one pantient. Single renal or upper ureteral stone was found in34(34.3%) patients, and multiple calculi in67(65.7%) patients. The stone burden was (25.4±12.8) mm. Of101cases, mild hydronephrosis was found in41cases, moderate hydronephrosis in42cases,and severe hydronephrosis in18cases.The kidney was punctured under ultrasonagraphic or/and fluoroscopic guidance. Once the pelvicalyceal system (PCS) was entered, a0.028-inch hydrophilic Zebra guidewire was manipulated down the ureter if possible, or coiled in a distant calyx. The track was dilated using a fascial dilator (Cook Urological, Spencer,IN) from8F to16F or20F. The corresponding peel-away sheath (Cook Urological, Spencer, IN) was placed as the percutaneous access port. Subsequently, a8.5F/11.5F nephroscope (Lixun Nephroscope, Richard Wolf, Knittlingen, Germany) was inserted to inspect the collecting system. Under direct vision, the stone was fragmented by pneumatic lithotripsy(Richard Wolf, Knittlingen, Germany).Most of the fragments(<0.3cm) were mainly pushed out with an endoscopic pulsed perfusion pump (MMC Yiyong, Guangzhou, China)and the big fragments (0.3cm-0.5cm) were extracted with a5F forceps (Richard Wolf, Knittlingen, Germany).At the end of the procedure of PCNL, the calculi were cleared under the monitoring of C-armed fluoroscopy and B-ultrasound. The head end of the ureteral catheter was adjusted in the center of renal pelvis. The peel-away sheath was removed when no active bleeding was confirmed.Results Of101patients,110tracts were established. Of110tracts, single tract was established in93(91.2%)cases, double tracts in7cases, three tracts and four tracts in one case respectively. Stone-free was found in95(94.1%) patients, and insignificant residual stone in6patients.The average operative time was (54.1± 13.7) min. The mean hemoglobin drop was (7.6±8.9) g/L. The visual analogue score on the first postoperative day was (2.0±1.6). The average time of ureteral catheter removal was (2.3±1.6) d. The average postoperative hospital stay was (3.4±1.9) days. The complications included one servere renal hemorrhage requiring selective renal arterial radiography and embolism,one urge incontinence, one perirenal hematoma, ten postoperative fever, two persistent macrohematuria, and two mild urinary extravasation.Conclusions Under the premise of strict surgical indications, micro-channel tubeless PCNL with a ureteral catheter was safe and effective for the treatment of upper urinary calculi. It can reduce hospitalization time and analgesic requirement, and promotes quality of life in selected patients. Section Ⅱ The differences of renal pelvic pressure in experimental white rabbits indwelling between a externalized ureteral catheter and a double-J stentObjective:To investigate the differences of renal pelvic pressure in experimental white rabbits between indwelling a externalized ureteral catheter and indwelling a double-J stent.Methods:Fifteen experimental white rabbits were chosen in the experiment. A externalized ureteral catheter was indwelled in the right upper urinary tract of white rabbits, and a double-J stent was in the left side. The renal pelvic pressure was messured by a baroreceptor. Compared the differences of of renal pelvic pressure in experimental white rabbits indwelling a externalized ureteral catheter with a double-J stent.Results:The renal pelvic pressure was (14.08±1.74) mmHg and (9.68 ±2.24) mmHg in the externalized ureteral catheter group and in the double-J stent group respectively. There are significant statistic differences between the two groups between the two groups.Conclusion:The renal pelvic pressure in the experimental white rabbit indwelling a externalized ureter catheter was lower than indwelling a double-J stent. Section Ⅲ Effectiveness of micro-channel tubeless percutaneous nephrolithotomy with a externalized ureteral catheter in selected patients:a prospective randomized studyObjective:We prospectively analysis the outcome of micro-channel tubeless percutaneous nephrolithotomy using two different stenting techniques (i.e., a externalized ureteral catheter compared with Double-J placement).Methods:109patients who were undergoing tubeless PCNL between December2011and January2013in our hospital were randomized to two groups:tubeless PCNL with ureteral catheter and tubeless PCNL with Double-J placement, respectively56cases and53cases.Inclusion criteria for the study were the stone burden less than4cm, no urinary infection,no serious bleeding or perforation in the collecting system during the operation, stone free or clinically insignificant residual fragments (CIRF<4mm), and no more than one access.The two groups were comparable with regard to age, sex, BMI, stone size, hydronephrosis. Factors evaluated included operative time, postoperative hemorrhage, visual analogue pain scale (VAS), analgesic requirement, hospitalization stay, hospitalization expenses and stent-related symptoms.Results:There were not statistically significance in the preoperative data and postoperative indexes. However, the patients with double-J stent need for postoperative cystoscopy to remove the Double-J stent, adds additional fees, and all patients were disturbed varying degrees stent-related discomfort.Conclusion:Tubeless PCNL with ureteral catheter is safe, as feasible as Double-J stent.,can replace the Double-J stent with ureteral catheter. And shows its unique superior.