despite expanded indications for conservative surgery of urothelial tumors ( ut - formerly transitional cell carcinoma ) of the upper urinary tract ( uut ) , radical nephroureterectomy ( nue ) with complete removal of the distal ureter including the bladder cuff is the standard surgical technique used for most patients with ut of the uut . choosing the best procedure for this group of patients in everyday clinical practice is frequently a challenging task . while laparoscopic nephrectomy as a part of nue was first described in 1991   and it is to - date broadly accepted , the approach to the distal ureter and the timing of the ureterectomy are still disputed . several techniques have been developed to remove the distal intramural part of the ureter during laparoscopic nue and it is very difficult to choose the best procedure for a given patient in everyday clinical practice . there is a risk of residual tumor at the stapling site and titan clips may constitute a nidus for the formation of cystolithiasis [ 5 , 6 ] . two groups [ 79 ] have described a technique for the division of the ureterovesical junction with a thermo  sealing  system ( ligasure atlas ) . we considered this modification of clnue as an excellent method and we have previously performed this on 14 patients . however , we found a significant risk of incomplete resection of the intramural part of the ureter . exclusive laparoscopic sharp excision of the bladder cuff with intracorporeal suturing [ 1115 ] appears too difficult for us . thus , we have decided to start clnue with excision of the ureterovesical junction with collin 's knife followed by clnue . the main problem with this procedure is the risk of occlusion of the ureter to prevent spillage of urine containing tumor cells during laparoscopic pluck nephroureterectomy . several methods have been described to date : ( 1 ) cauterization of the ureteric ostium only , ( 2 ) endoloop [ 16 , 17 ] , ( 3 ) hem - o - lok clip [ 1820 ] , or ( 4 ) fibrin sealant . we chose to close the ureter with a lockable hem - o - lok clip , which was introduced through a 5 mm intravesical port in the suprapubic area rather than endoscopically [ 18 , 19 , 20 ] . we have labeled this technique as clnue - wilc ( with intravesical lockable clip ) . in this study the study is prospective , but due to the absence of a standard technique for nue , the study was not randomized and comparative . from 1/2010 to 1/2012 , 38 patients with suspected ut of uut were indicated for surgical treatment . four underwent conservative surgery ( one ho : yag ablation , one ureteroscopic resection , one nephroscopic resection with resectoscope , and one open resection of the ureter ) and 34 nue . thirteen underwent some type of open surgery ( advanced cases with open nephrectomy or laparoscopic nephrectomy with open ureterectomy for tumor of the distal ureter ) and 21 nue by clnue- ivlc ( main inclusion criteria : not suitable for conservative treatment , no tumor of distal ureter , no advanced tumor by ct , no contraindications to laparoscopy , or no concomitant bladder tumor ) . the ureterovesical junction is excised transurethrally with collin 's knife ( the paravesical adipose tissue must be clearly visible ) . from the suprapubic region , the stump of the ureter is grasped with biopsy forceps and on the end of ureter , a hem - o - lok clip size ml is applied ( the applicator is introducible through the 5 mm port ) . in broader ureters , the patient is rotated to the flank position and a standard laparoscopic nephrectomy via a transperitoneal approach is performed [ 10 , 22 ] . the transperitoneal approach is more familiar to us than the retroperitoneoscopic one . one additional 5 mm port in the suprapubic region is introduced ; the skin incision from the previous endoscopic phase is used . the ureter is dissected along and under the iliac vessels with a harmonic scalpel or ligasure advance or blunt tip 35 mm . this phase is delicate due to the relatively narrow operation space and the close relation of iliac vessels and the bowel . the ureter is completely separated and the hem - o - lok clip must be clearly visible to constitute proof of completion of the ureterectomy . a few points to emphasize include : four complications ( clavien ii 2x , iiib and v )    wound infection at the site of extraction ( staphylococcus aureus ) , urine leakage from the pelvic drain for 6 days ( bladder catheter was removed on the 8 postoperative day following cystoradiography that did not reveal leakage ) , one open prostatectomy on the 2 postoperative day because of an enlarged prostate ( bph with hematuria ) , and one patient died of heart failure on the day of operation . in four cases ( 19.0% ) application of the clip failed and clnue was concluded with a non - occluded ureter and the risk of dissemination of tumor cells in urine paravesically . in the first case the patient had a ureteral stent and the ureter was incrassate , which is why we did not want to apply 10 mm port to facilitate the introduction of the hem - o - lok clip size l. in another case , the stented ureter was also incrassate and we introduced a 10 mm port to the urinary bladder and applied a size l clip without difficulty . there was one incidence with the inability to grasp the ureter by endoscopic forceps . in two cases the laparoscopic nephrectomy was converted to the open surgery ( flank incision and lumbolaparotomy )  in one case this was due to extensive adhesions in the abdominal cavity ( a history of open cholecystectomy with evacuation of subphrenic abscess ) , and in the other two cases it was due to advanced tumor growth with perirenal and periureteral adhesions . in three cases , laparoscopic nephrectomy was followed by open distal ureterectomy with the standard pluck method , because the laparoscopic approach was not feasible due to poor access of the laparoscopic instruments to the small pelvis . four patients with non - ut histology were judged to be ut by preoperative imaging . follow - up ( mean 10 , range : 0 - 22 months ) , including results of the control endoscopy , are known in all patients . one patient with uc of the renal pelvis pt2n0m0g2 had uc in the contralateral distal ureter and died after 11 months due to extensive metastatic disease , mainly to bone . abbreviations : ae  adrenalectomy for adenoma , bcg  history of intravesical instillation of bcg , bt  urinary bladder tumor , eskd  end - stage kidney disease , l  left , m  male , mo right , turb  transurethral resection of bladder tumor , up - um  ureter proximal - middle , uc notes : all cases were n0m0 ; time  of whole procedure ( endoscopy , rotation of patient , laparoscopy ) ; non - uc histology : tumors were described by radiologists on ct / mri as a suspicious uc tumor . it should be noted that the aim of this work is not to comprehensively discuss the whole complex problem of nue . our experience prompted us to review this topic in two recent publications [ 10 , 22 ] and now we will focus the discussion on complete laparoscopic nue with emphasis on the method of removing the distal part of the ureter including the bladder cuff . in our view , due to the disadvantages mentioned in the introduction , the method involving a stapler should be abandoned . the other options of distal ureterectomy as a part of clnue are as follows : ( 1 ) a thermosealing technique [ 7 , 8 , 9 ] , ( 2 ) the sharp excision of the bladder cuff with intracorporeal suturing ( a purely laparoscopic technique ) [ 11 , 12 , 15 ] including modification with a bulldog clamp , ( 3 ) robotic , or ( 4 ) purse string technique . the steps of the endoscopic phase in lithotomy position . the ureterovesical junction is excised transurethrally with a collin 's knife to the paravesical adipose tissue . the stump of the ureter is grasped with biopsy forceps and the end of the ureter is clipped with a hem - o - lok clip size ml ( an applicator is introduced through the 5 mm port inserted as an epicystostomy ) . as pointed out previously , the thermosealing system technique has the risk of leaving the intramural part of the ureter intact . the laparoscopic ne with ensuing sharp excision of the ureterovesical junction and closing of the defect with suture is an ideal but challenging method . we consider the technique with any variant intracorporeal suturing technically more challenging and time consuming [ 10 , 22 ] . the variant with the da vinci robotic system [ 24 , 25 ] decreases the technical difficulty of intracorporeal suturing . the disadvantages of the da vinci system include : high cost , lack of tactile sensation , long set - up time , and unavailability of the robotic system in many hospitals . an exotic technique is the pneumovesicum approach   in which three 5 mm ports are introduced to the bladder and insufflated with co2  pneumovesicum ( 10 - 12 mm hg ) . the distal ureter , bladder cuff , and intramural ureter are then completely dissected free using electrocautery . as soon as the distal ureter is dissected an endo - loop knot is used to ligate the ureter . we do not have experience with this technique and we feel this technique to be complicated . the ureter is excised through a laparoscopic single port introduced to the urinary bladder and the defect is closed with intravesical suture . six ports , on the left side , but five usually suffice . the same skin incision as for the epicystostomy is used for the suprapubic port . due to the factors mentioned above we prefer a variant of excision of the ureterovesical junction but with another method for sealing of the ureter . we have long - term experience with excision of ureterovesical junctions using collin 's knife . previously we used it as a pluck technique combined with open and thereafter laparoscopic or retroperitoneoscopic nephroureterectomy , and , later on , we also used it as a part of antegrade mini - invasive nue . 's idea [ 18 , 19 ] of endoscopically closing the excised ureter with lockable clip to be excellent , although the introduction of the hem - o - lok clip via endoscope appears to be difficult . pathak et al . performed their technique in 25 cases with a mean total operative time of 164 ( range : 105 - 235 ) minutes . no pelvic complications in were reported and there were no perivesical tumor recurrences with mean follow - up of 26 ( range : 11 - 44 ) months . we have decided to apply the hem - o - lok clip size ml via an intravesical 5 mm port introduced through the suprapubic area . regarding our first nine cases , we had found the exact same method described in the literature . suprapubic transvesical single - port technique for control of lower end of ureter during laparoscopic nephroureterectomy  . the dissected nephroureterectomy specimen during the operation . the tumor can be seen in the upper calyx with hem - o - lok size ml at the end of the ureter ( see detail ) . reportedly , occlusion of the ureter may be performed instead of clip with electro - coagulation only ( it is probably less reliable ) or with fibrin sealant injection . clnue- ivlc is a relatively simple , reproducible , and minimally invasive method with minimal risks of tumor spillage and seeding . the main disadvantage seems to be the risk of an unclosed defect of the urinary bladder , but based on our own experience , as reported in this paper and the available literature , we have not found any significant complications emerging from this . another disadvantage is failure in applying the hem - o - lok clip , in which the technique is concluded without closing the ureter , and is generally thought to carry a higher risk of extravesical tumor recurrence , but as described recently , this technique has comparable oncological results to the open distal ureterectomy [ 3 , 6 ] . failures in clip application were experienced only in early cases and , with increasing experience , this problem was avoided . importantly , if needed , the endoscopic phase can be transformed to open nue or it can be combined primarily with open surgery . some may consider conversion to open distal ureterectomy / nephrectomy as a failure of the method . the method whereby closing of the ureter is performed allows the procedure ( nue ) to be completed safely in complicated cases ( obesity , advanced cases , previous intraabdominal surgery etc . ) .
introductionwe present a cohort of patients with low - stage pelviureteric neoplastic disease who underwent complete laparoscopic nephroureterectomy ( clnue ) with intravesical lockable clip ( ivlc ) . due to the absence of a standard technique of nue , 
 the study was not randomized.materialsfrom 1/2010 to 1/2012 , 21 patients were subjected to clnue - ivlc . 
 the first step was transurethral excision of the ureterovesical junction with collin 's knife deep into the paravesical adipose tissue . 
 the ureter was grasped with biopsy forceps and the distal end of the ureter was occluded with lockable clip . 
 the applicator was introduced through a 5 mm port inserted as an epicystostomy . 
 the patients were rotated to flank position and clnue followed . 
 the endoscopically introduced clip on the distal ureter is proof of completion of the total ureterectomy.resultsthe mean operation time was 161 ( 115 - 200 ) min . in four ( 19.0% ) , the application of the clip failed and clnue was completed with non - occluded ureter . in three cases , 
 subsequent laparoscopic nephrectomy was converted to open surgery . in two cases , 
 the distal ureterectomy was completed with pluck technique through a lower abdominal incision that was also used for extraction of the specimen . 
 there were four complications ( clavien ii 2x , iiib , v ) . 
 follow - up was available for all  mean 10.6 ( range : 0 - 25 ) months . 
 one died of disease generalization within 11 months.conclusionclnue-ivlc is fast and safe . 
 if needed , the endoscopic phase can be switched to open nue . 
 disadvantages include : the need to change the position of the patient , the risk of inability to apply the clip on the distal ureter , and the risk of an unclosed defect of the urinary bladder .