TITLE PAGE
FULL TITLE: DJ Stent removal Innovation – the Vellore Snare Technique
AUTHORS:
Dr Sharada Sundaramurthy
Dr Reju Joseph Thomas
Dr Jujju Jacob Kurian
Dr Koushik Herle
Dr Jeyaseelan
Dr John Mathai
AFFILIATION:
Department of Pediatric Surgery,
Christian Medical College
Vellore, India
AUTHOR FOR CORRESPONDENCE:
Dr Jujju Jacob Kurian
Postal Address: Department of Pediatric Surgery, Christian Medical College Hospital
Vellore, Tamil Nadu, India- 632004
Email Id: paedsur@cmcvellore.ac.in
Ph No: 91-416 2283369
SUMMARY
Background: DJ stents placed at the end of pediatric urological procedures require another cystoscopy under general anaesthesia for removal. The second author developed a reproducible technique for snaring the DJ stent using a feeding tube (6 or 8 FG) and a 3/0 prolene suture perurethrally . Having demonstrated the proof of concept, ethical clearance was obtained for an institutional randomised controlled trial.
Objective:
- To describe the Vellore catheter snare technique for DJ stent removal
- To study the efficacy of the technique.
- To compare the costs of the snare technique in our centre on an intention to treat basis.
Study design: A Randomized control trial with parallel groups as a non-inferiority study.
Results: Forty children with unilateral indwelling DJ stents were enrolled from January 2018 to August 2018. They were randomized by unequal allocation (1:3) to cystoscopic and snare removal arms. The snare was successful in 86.67% (26/30)of those attempted and cystoscopy in 100% (10/10). The p value was insignificant (p=0.77). The average cost for cystoscopic removal of stent under GA was Rs 14,579/- and by the snare technique (on an intention to treat basis) was Rs 5636/-.
Discussion: In children, perurethral catheterisation is a tolerable outpatient / ward procedure while cystoscopy is not. Flexible cystourethroscopes are currently expensive and not yet routinely used in children for DJ stent removal. The CMC Vellore snare technique using common disposables, in 86% of children circumvented the need for inpatient admission, disinfected equipment usage and operating theater time.
Conclusion: The Vellore Snare Technique for DJ stent removal is a practical safe low cost safe alternative to Cystoscopic removal of DJ stents in children.
Keywords: DJ stent removal, Children
INTRODUCTION: Double J stents are placed ubiquitously after pyeloplasty; they are used as a temporising measure in infants with vesicoureteric junction obstruction, and after other procedures on the ureter. After serving its purpose, for its removal, a cystoscope, more often a rigid one is passed urethrally under general anaesthesia, the DJ stent grasped with a pair of stent removal forceps and withdrawn with the cystoscope. Even though it is over in a few minutes, it places demands on the time of admitting surgical and nursing teams, inpatient beds, theatre personnel, anesthesia team, presentation of sterile cystoscopic instruments, their cleaning and sterilisation, operating room time. All of which are transferred as costs to the patient. Except when being used to replace a stent, this cystoscopy serves no other purpose than the stent removal itself.
The second author, at Christian Medical College, Vellore, conceived of the snare as a means for removing DJ stents in pediatric patients. After ethical clearance (CTRI/2017/09/009926), this was developed as a bladder catheterization procedure and evaluated against the gold standard of cystoscopic removal of DJ stent.
MATERIALS AND METHODS:
Forty children for DJ stent removal whose parents gave consent for the Randomized controlled trial were enrolled from January 2018 to August 2018. They were randomized by unequal allocation (1:3) to cystoscopic and suture loop method removal arms. Stratified Block randomization was done with the blocks of 4 and 2 with the proportion of allocation of these blocks was 50% and 50% using SAS code by centralized allocation with no masking or blinding.
The inclusion criterion was radiologic confirmation of lower end of DJ stent within the bladder. Exclusion criterion was an indication for a diagnostic or therapeutic cystoscopy.
DESCRIPTION OF THE METHOD: A 6 or 8F feeding tube had its hub end cut off between 28 and 30cm mark. A monofilament 3-0 polypropylene suture 90 cm long without needle was reverse loaded through the adjacent eyes of the feeding tube (6F or 8F) leaving a loop at the distal end and the free ends exiting proximally. Lignocaine jelly 2% was instilled in the urethra, and the loop end was passed in to the urinary bladder as in a routine catheterization procedure. Once within the bladder confirmed by drainage of urine, the tube was twisted around a few times. The loose ends of the suture were then pulled tight and the infant feeding tube removed, usually bringing the entangled stent out with it. If unsuccessful, it was repeated a maximum of two more times. Intravenous sedation was administered and monitored by a team member privileged and prepared for deep sedation in children. Midazolam 0.5 to 1mg/kg was used for children under seven years of age and in addition iv Ketamine 1 to 2mg/kg given to those over seven years of age. Children to receive midazolam were fasted for 1 hour, whereas older children receiving ketamine were fasted for 6 hours. Children for whom the stent could not be removed by the suture loop method (n=4) underwent cystoscopic removal the next day electively.
Children randomized to the cystoscopic method underwent DJ stent removal under anesthesia as done routinely and discharged the same day if satisfactorily recovered post procedure. A dose of Ampicillin and Gentamicin were administered prior to either technique.
The primary outcome measured was success of stent removal by suture loop method. Secondary outcomes were duration of hospital stay, fasting duration, urinary tract infection post procedure, operating theater time for cystoscopic removal. Patient characteristics and parental satisfaction post procedure was looked at. Direct and indirect costs were calculated and cost analysis was done noting the Incremental Cost Effective Ratio.
RESULTS: Forty children, age 0-16 yrs, were enrolled into the study from January 2018 to August 2018 and randomized to cystoscopy (n=10) and catheter snare method (n=30) removal arms in a ratio of 1:3. The age, gender characteristics, laterality of DJ stents, success rate, duration of hospital stay and costs in the two groups are shown in Table 1. Seventy percent of children in either arm were less than seven years of age (7/10) and (22/30). Pyeloplasty for pelviureteric junction obstruction was the predominant previous surgery (Table 2). Pre-procedure skiagram of the abdomen done in 34 children showed 16 stents at the region of the pubic symphysis, 10 stents beyond the symphysis and 8 falling short of the symphysis. Average duration of hospital stay for children undergoing stent removal by suture loop method was 6 hours. As paediatric daycare anaesthesiologist facility is unavailable at our institution, the average length of stay for the cystoscopic patients was 28 hours. 26 of 30 stents (86.67%) were successfully removed by the catheter snare method. All stents that reached the pubic symphysis (16/16) and 9 of 10 stents beyond the symphysis were successfully remived. Three of 4 children in whom the stent could not be removed, the stent was short of pubic symphysis (p=0.003), the fourth had stent beyond the symphysis. The ward procedure time for DJ stent removal was not measured. The mean operating theater time used for cystoscopic procedure was 38 minutes (range-20 minutes to 50 minutes, measured from wheeling out of previous patient to wheeling out of stent removal patient. Efficacy of intervention in outcome as success was -0.25 to -26.35.
Post procedure one patient in the suture loop removal group developed prolonged dysuria (>48 hours), urine analysis showed growth of 8500 colony forming units of yeast and responded to oral fluconazole. The cost of this patient as well as of the failed four cases have been included in calculating cost of the groups. The average cost was Rs 5636 for the catheter snare method and Rs 14,579 for the cystoscopic method. Incremental cost effective ratio was Rs 68,792.
At the end of the snaring procedure, a set of four questions were asked of the parents (Table 3). None of the parents felt any undue anxiety as compared to a procedure done in operating room. None of the patients were found in pain at the end of the procedure. Of the four children whose stents could not be removed by snaring, two sets of parents expressed unhappiness and said they would have rather had this procedure done by cystoscopy in operating theater.
DISCUSSION: We describe a reproducible catheter snare technique of DJ stent removal. The technique avoided cystoscopy under general anaesthesia in 87% of instances. There were gains in terms of theatre time and cost to patient in the majority. The position of the stent in the X ray was an important predictor of failure of removal by suture loop method. There were 4 failures with parent recrudescence in 2 of them. There was 1 fungal urinary infection, a morbidity of 3%. The technique though it has a high success rate still needs the backup option of Cystoscopy under general anaesthesia.
CONCLUSION: We describe the CMC Vellore catheter snare technique as a theatre time conserving strategy for busy tertiary care institutions and as a cost reducing option that can be offered as a reduced price package for DJ stent removal for paying patients.
ACKNOWLEDGEMENT:
FUNDING: The study was funded by Christian Medical College, FLUID Research Grant and Department of Pediatric Surgery.
REFERENCES
Table 1a: Distribution of Categorical Variables among Intervention groups
Intervention
Cystoscopy Loop
n % n %
Gender
Male 8 80.0 28 93.3
Female 2 20.0 2 6.7
Side
Left 4 40.0 23 76.7
Right 6 60.0 7 23.3
X-Ray
At symphysis 3 30.0 16 53.3
Long 1 10.0 9 30.0
Short 6 60.0 5 16.7
Sedation
GA 9 90.0 0 0.0
Midaz 1 10.0 22 73.3
Ketamine 0 0.0 8 26.7
Complications
No 10 100.0 29 96.7
Yes 0 0.0 1 3.3
Table 1b: Distribution of Continuous Variables among Intervention groups
Intervention
Cystoscopy Catheter Snare
Mean/Median SD/(IQR) Mean/Median SD/(IQR)
Age 8.5 (6.0, 96.0) 36.0 (12.0, 96.0)
Duration 63.0 (59.0, 69.0) 48.0 (14.0, 57.0)
Hospital Stay 28 6
NPOmean(SD) 7 2 6 1
ORTimemean(SD) 38 10 41 12
DirectCost 13419.5 (12251.0, 14139.0) 4910.0 (4750.0, 5324.0)
Indirect Cost 1500.0 (1000.0, 2000.0) 650.0 (500.0, 1000.0)
TotalCost 14579.0 (13751.0, 17586.0) 5636.5 (5181.0, 6826.0)
Table 2: Significance of position of stent on X ray
X Ray Finding Loop Not removed Failure Rate P value
At Symphysis 16 0 0%
0.003
Long 9 1 11%
Short 5 3 60%
Table 2: Efficacy of Intervention in outcome as Success
Variables Success
Yes No
n % n %
Loop 26 86.7 4 13.3
Cystoscopy 10 100.0 0 0.0
Diff -13.3 (-26.35, -0.25)
Figure 1: Point estimate with Confidence Interval
