 to stent or not to stent  is a point debated since long time .
this assumes importance in children and infants requiring intervention for ureteropelvic junction obstruction ( upjo ) .
although literature supports  stentless  pyeloplasty , in laparoscopic pyeloplasty particularly , it is a common practice to stent the anastomosis . the advantages and disadvantages of both the approaches are well known . in infants , the urethra is narrow and runs the risk of injury and subsequent strictures with surgical manipulations .
in addition , the stent - related morbidities which include dysuria and infections may make the postoperative course of the infant unpleasant . in the days of open surgery
, it was our policy to employ the technique of open insertion of stent along with a nephrostomy , just prior completion of the anastomosis .
this served the purpose of nephrostomy acting as a safety valve prior to removal of splint . in this article
, we describe the technique of ante grade access of the ureter , thus potentially avoiding the urethral manipulations and the associated complications .
a 7.5mhz ( b  k medical , denmark ) ultrasound probe with puncture attachment is used .
a pediatric probe is used for this purpose [ figure 1 ] . a 18 gauge echotip disposable two part trocar needle ( cook urological inc , indiana , usa ) which is available as a two part needle was used .
a 0.035 guide wire or alternatively a terumo glide wire ( terumo corporation , tokyo , japan)with alken two part metallic needle helps simultaneously passing two guide / glide wires [ figure 1 ] . the dilatation is done with angiotech one step dilator ( pbn medicals , denmark ) , a14 fr nephrostomy tube ( devon innovations ( p ) ltd , parwanoo , hp , india ) with a 5 fr open end ureteric catheter ( devon innovations ( p ) ltd , bangalore , india ) is used .
the armamentarium ( a ) telescopic metal two part needle ( b ) pediatric ultrasound probe the first step involves positioning the patient in a prone position , although the same can be done in supine position .
line diagram ( a ) and picture ( b ) illustrating ultrasound - guided calyceal puncture the needle is housed in the needle attachment of the ultrasound probe and the posterior calyx identified [ figure 2 ] .
the  key  for a successful ultrasound puncture is that the needle should be seen throughout the trajectory which includes the skin , subcutaneous tissue , cup of the calyx and the calyx in concern [ figure 3 ] .
technique of ultrasound - guided access ( a ) an egress of clear fluid suggesting entry in the pelvicalyceal system ( b ) a successful ultrasound puncture - the needle should be seen throughout the trajectory which includes the skin , subcutaneous tissue , cup of the calyx and the calyx in concern an egress of clear fluid suggests entry in the pelvicalyceal system which can further be confirmed with a contrast study [ figure 3 ] . next a guide wire is parked in a distant calyx and the tract dilated up to 14 fr using a screw dilator .
an alken needle , which is a two part needle , helps in passing a second guide wire after removing the inner stylet [ figure 4 ] .
once both guide wires are in place , one wire is used for passing a ureteric catheter and the second one is used for placing a nephrostomy tube [ figure 5 ] .
the salient feature of our technique is that all steps of percutaneous access which include access and dilation are done solely using ultrasound guidance .
( a ) the needle and guide wire are clearly seen in real time ultrasound , thus avoiding bowel injury ( b ) ( line diagram ) and c ( picture):-two glide wires passed into the renal pelvis through the telescopic metal two part needle after removing the inner stylet ( a ) line diagram showing completed anastomosis with nephrostomy and ureteric catheter ( splint ) in situ , ( b ) laparoscopic pyeloplasty performed after the ureteric catheter and percutaneous nephrostomy is in place c ) opened up renal pelvis showing presence of both malecot catheter and ureteric catheter in pelvis ( d ) ultrasound showing flower of malecot catheter opened in pelvis after the ureteric catheter and percutaneous nephrostomy is in place , the laparoscopic pyeloplasty is performed .
once the pelvis is opened and the ureter spatulated , the ureteric catheter which is already coiled in the pelvis is passed under direct vision into the ureter after the posterior layer is completed following which the anastomosis is completed [ figure 6 ] .
placement of ureteric splint under vision once the posterior wall is completed , the ureteric catheter is passed into the ureter under vision ureteric catheter is removed on the 3 post operative day and nephrostomy is clamped .
the modified technique was successfully done in five patients aged less than one year old .
a 7.5mhz ( b  k medical , denmark ) ultrasound probe with puncture attachment is used .
a pediatric probe is used for this purpose [ figure 1 ] . a 18 gauge echotip disposable two part trocar needle ( cook urological inc , indiana , usa ) which is available as a two part needle was used .
a 0.035 guide wire or alternatively a terumo glide wire ( terumo corporation , tokyo , japan)with alken two part metallic needle helps simultaneously passing two guide / glide wires [ figure 1 ] . the dilatation is done with angiotech one step dilator ( pbn medicals , denmark ) , a14 fr nephrostomy tube ( devon innovations ( p ) ltd , parwanoo , hp , india ) with a 5 fr open end ureteric catheter ( devon innovations ( p ) ltd , bangalore , india ) is used .
the armamentarium ( a ) telescopic metal two part needle ( b ) pediatric ultrasound probe
the first step involves positioning the patient in a prone position , although the same can be done in supine position .
line diagram ( a ) and picture ( b ) illustrating ultrasound - guided calyceal puncture the needle is housed in the needle attachment of the ultrasound probe and the posterior calyx identified [ figure 2 ] .
the  key  for a successful ultrasound puncture is that the needle should be seen throughout the trajectory which includes the skin , subcutaneous tissue , cup of the calyx and the calyx in concern [ figure 3 ] .
technique of ultrasound - guided access ( a ) an egress of clear fluid suggesting entry in the pelvicalyceal system ( b ) a successful ultrasound puncture - the needle should be seen throughout the trajectory which includes the skin , subcutaneous tissue , cup of the calyx and the calyx in concern an egress of clear fluid suggests entry in the pelvicalyceal system which can further be confirmed with a contrast study [ figure 3 ] . next a guide wire is parked in a distant calyx and the tract dilated up to 14 fr using a screw dilator .
an alken needle , which is a two part needle , helps in passing a second guide wire after removing the inner stylet [ figure 4 ] .
once both guide wires are in place , one wire is used for passing a ureteric catheter and the second one is used for placing a nephrostomy tube [ figure 5 ] .
the salient feature of our technique is that all steps of percutaneous access which include access and dilation are done solely using ultrasound guidance .
( a ) the needle and guide wire are clearly seen in real time ultrasound , thus avoiding bowel injury ( b ) ( line diagram ) and c ( picture):-two glide wires passed into the renal pelvis through the telescopic metal two part needle after removing the inner stylet ( a ) line diagram showing completed anastomosis with nephrostomy and ureteric catheter ( splint ) in situ , ( b ) laparoscopic pyeloplasty performed after the ureteric catheter and percutaneous nephrostomy is in place c ) opened up renal pelvis showing presence of both malecot catheter and ureteric catheter in pelvis ( d ) ultrasound showing flower of malecot catheter opened in pelvis after the ureteric catheter and percutaneous nephrostomy is in place , the laparoscopic pyeloplasty is performed .
once the pelvis is opened and the ureter spatulated , the ureteric catheter which is already coiled in the pelvis is passed under direct vision into the ureter after the posterior layer is completed following which the anastomosis is completed [ figure 6 ] .
placement of ureteric splint under vision once the posterior wall is completed , the ureteric catheter is passed into the ureter under vision ureteric catheter is removed on the 3 post operative day and nephrostomy is clamped .
the modified technique was successfully done in five patients aged less than one year old .
the indications for stenting are well known , they include pyeloplasty in the presence of solitary functioning kidney , infection , or a previous failed procedure .
placing a stent in a retrograde fashion involves urethral manipulation and the attendant complications ; in addition , this involves an additional procedure for removal of the stent .
the advantages of stent placement following pyeloplasty include decreased risk of collection or edema , maintaining ureteric alignment woo et al .
, in their study on the impact of internal stenting on the surgical outcome of dismembered pyeloplasty in infants under the age of 12 months with the open approach .
they observed statistically significant increase in urinary leaks , length of hospital stay and need for repeat pyeloplasty in non stented versus the stented group . a variety of techniques
have been described to place a stent or a splint antegrade thus avoiding the need for cystoscopy during insertion or removal .
taveres et al describe a technique for inserting an internal - external nephroureteral antegrade stent during laparoscopic pyeloplasty which can be removed in clinic as outpatient .
the advantages of the technique we have described are the following : 
 1)the ureteral access can be gained with ultrasound guidance .
this minimizes the risk of bowel injury as well radiation in these patients.2)the nephrostomy tube acts as a safety valve and can be clamped to confirm the integrity of the anastomosis prior to its removal.3)if needed , the ureteric catheter can act as conduit to negotiate a ureteral stent across the anastomosis .
the nephrostomy tube acts as a safety valve and can be clamped to confirm the integrity of the anastomosis prior to its removal .
if needed , the ureteric catheter can act as conduit to negotiate a ureteral stent across the anastomosis .
we acknowledge that there are a few disadvantages with this technique and the most significant is the need for additional equipment and expertise for gaining percutaneous renal access .
in addition , at times , repeated attempts for gaining access lead to extravasation and oozing , which might hamper the vision and the anastomosis .
in infants with pelviureteric junction obstruction when undergoing laparoscopic pyeloplasty ; ultrasound - guided antegrade nephroureteric , ureteric catheter placement is a safe technique .
it avoids need for urethral manipulation for insertion and removal of stent , decreases radiation exposure to infant .
furthermore , nephrostomy tube acts as a safety valve to confirm the integrity of anastomosis and ureteric catheter may act as conduit to put another ureteric stent if necessary at later date .
this technique requires some additional equipments and expertise to get percutaneous renal access which can be mastered with practice .
 background : access to urethras and ureters of infants may be hazardous and injurious through an endoscopic route . placement and removal of stents in infants requires anaesthesia and access through these small caliber urethras . 
 we describe our technique of placing antegrade splint during a laparoscopic pyeloplasty in these infants.materials and methods : an ultrasound - guided percutaneous renal access is obtained . 
 telescopic metal two part needle is passed into the kidney over a guide wire . 
 a second guide wire is passed through the telescopic metal two part needle . 
 the tract is dilated with 14 fr screw dilator . over one guide wire 
 , a 5 fr ureteric catheter is passed and coiled in the renal pelvis . over the other wire , 
 a 14 fr malecot catheter is placed as nephrostomy . 
 laparoscopic pyeloplasty is then done . during pyelotomy , 
 the ureteric catheter is pulled and advanced through the ureter before the pyeloplasty is completed . 
 the ureteric catheter thus acts as a splint across the anastomosis . 
 ureteric catheter is removed on the 3rd post operative day and nephrostomy is clamped . 
 nephrostomy is removed on 4th post operative day if child is asymptomatic . 
 the modified technique was successfully done in five patients aged less than one year old . 
 all patients tolerated the procedure well . 
 post operative period was uneventful in all.conclusion:ultrasound-guided ante grade nephroureteral ureteral splint for infant laparoscopic pyeloplasty is safe . 
 it avoids the need for urethral instrumentation for insertion and removal of stents in these small patients . 
INTRODUCTION
MATERIALS AND METHODS
Instrumentation
Technique
DISCUSSION
CONCLUSION