Stenting Antegrade Via Veress Needle during Laparoscopic PyeloplastY ("SAVVY" Technique).

AIM: The aim of the study is to report the outcomes of different stenting techniques during laparoscopic pyeloplasty (LP).
MATERIALS AND METHODS: This study was a retrospective audit of duration of stenting, complications encountered, and operative outcomes of LP in children older than 3 years.
RESULTS: Retrograde cystoscopic prestenting took significantly longer time (17.2 min) and the presence of stent hindered in anastomosis. Antegrade stenting without guide wire took longer time (9.6 min), and in some, there was difficulty in negotiating distal ureter. Antegrade stenting over guide wire, through a 14-gauge intravenous cannula, took significantly less time (7.3 min) although the cannula got kinked and the stenting was difficult in some as the length of the cannula was short and it did not reach anastomotic site. "Stenting Antegrade Via Veress needle during laparoscopic pyeloplastY" ("SAVVY" technique) favored by authors has the least stenting duration (4.8 min) and minimum failures (P = 0.01, ANOVA). The needle is wide enough to pass a 4-Fr stent and long enough to reach the anastomotic site.
CONCLUSION: SAVVY technique saves time during LP with least failures and is a useful stenting technique in children.

INTRODUCTION

Laparoscopic pyeloplasty (LP) has become an established procedure for the management of ureteropelvic junction (UPJ) obstruction in children. With improvement in functional success, the focus has shifted to reduce the operating time. Stenting during LP can be performed by several methods. During the initial periods, retrograde cystoscopic stenting was done, and then, the patient was repositioned for LP. However, this approach took longer, and the author tried different antegrade stenting methods. This is a retrospective study auditing different stenting techniques by a single surgeon. The authors favored method is described as “Stenting Antegrade Via Veress needle during laparoscopic pyeloplastY” (“SAVVY” technique).

MATERIALS AND METHODS

Among 120 patients who underwent LP between 2012 and 2017, 24 patients less than 3 years of age were excluded from the study to minimize age-related confounding factors such as narrow vesicoureteric junction (VUJ). The remaining 96 patients were divided into four groups based on the method used for stenting. Group 1 (n = 27): retrograde cystoscopic stenting before positioning the patient; Group 2 (n = 23): antegrade stenting without guide wire (closed end stent was pushed in through 10-mm trocar and advanced without guide wire using laparoscopic instruments); Group 3 (n = 21): antegrade stenting over guide wire through 14-gauge intravenous (IV) cannula inserted through the abdomen; and Group 4 (n = 25): antegrade stenting over guide wire through Veress needle inserted through the abdomen at UPJ level. Figure 1 describes the technique. In all patients, the transperitoneal approach and the same technique were used by the same surgeon. A 4-Fr stent of appropriate length was used in all the patients. The distal stent position was confirmed with the help of C-arm screening in all the patients immediately. All the patients had indwelling urethral catheter for 48–72 h and discharged on day 3. The stent was removed after 4–6 weeks under general anesthesia. Postoperative follow-up involved three monthly ultrasonograms and a nuclear scan at 1 year to assess drainage. In addition to time taken for stenting, complications encountered during stenting and operative outcomes were analyzed. The results were also analyzed using one-way ANOVA and Student's t-test.

Figure 1

Stenting Antegrade Via Veress needle during laparoscopic pyeloplastY (“SAVVY” technique). (a) Stillete of the Veress needle is removed and free passage of stent with guide wire through the needle is checked. (b) After completing posterior layer of pyeloplasty, Veress needle is inserted transabdominally and the tip negotiated to direct the stent toward the ureteric anastomosis. (c) Double-J stent is inserted over guide wire through the Veress needle and stent pusher is used to advance the stent into ureter. (d) After confirming stent position, the proximal coil is placed in the pelvis. Anterior layer of pyeloplasty is completed after this step

RESULTS

There was no significant difference in the age group or duration of pyeloplasty between groups. Table 1 summarizes the outcomes in each group. The mean (standard deviation) time taken in minutes for stenting was as follows: Group 1: 17.2 (5.25), Group 2: 9.6 (4.4), Group 3: 7.3 (2.3), and Group 4: 4.8 (1.8) and was significantly less in Group 3 and Group 4 (P = 0.01, ANOVA). The stent got pulled up during anastomosis in 5/27 patients in Group 1, warranting antegrade stenting. In Group 2, in 3/23 patients, the stent could not be passed across VUJ due to the lack of guide wire. These patients needed cystoscopic insertion after repositioning. In Group 3, kinking of the cannula/lack of length delayed stenting in 5/21 patients. Three patients underwent cystoscopic insertion and two patients were stented using Veress needle. In Group 4, the Veress needle helped in inserting guide wire easily and none of the above difficulties were encountered. Stent-related complications, such as hematuria, spasm, or stent migration, were not encountered in these patients. There was no significant difference in postoperative complications or operative outcomes in any of these patients.

Table 1

Outcomes of four different methods of stenting during laparoscopic pyeloplasty

	Group 1 (n=27)	Group 2 (n=23)	Group 3 (n=21)	Group 4 (n=25)	P
Mean age (years)	7.5	7.8	8.3	6.5	0.35
Mean time taken for stenting (min)	17.2 (5.25)	9.6 (4.4)	7.3 (2.3)	4.8 (1.8)	0.01
Stent-related difficulties	5/27	3/23	5/21	0/25	0.01
Early complications (urine leak, etc.)	1	0	1	0	NA
Recurrence at 1-year follow-up	0	0	0	0	NA

NA: Not available

DISCUSSION

Multiple techniques exist for stenting during LP. Kalkan et al.[1] reported a modified antegrade stenting using an Amplatz dilator. Yu et al.[2] found antegrade stenting difficult in less than 5 old due to the narrowing at VUJ. They inserted a ureteric catheter up to mid-ureter cystoscopically, and it was anchored to a stent extracorporeally and pulled down later. A similar antegrade technique was reported by Chen et al.[3] Curcio et al.,[4] and Rodrigues et al.[5] They inserted a ureteric catheter through cystoscope before pyeloplasty. After completing posterior layer of anastomosis, a guide wire was passed up the ureteric catheter, and the ureteric catheter was replaced with antegrade double-J stent. Kocherov et al.[6] exteriorized the pelvis after deflating abdomen and performed open antegrade stenting. Chandrasekharam[7] found antegrade stenting less successful in children with a mean age of 1.5 years and favored retrograde stenting. However, Arumainayagam et al.[8] and Mandhani et al.[9] found that antegrade stenting was quicker and more effective than retrograde method. Helmy et al.[10] described an external pyeloureteral stent instead of indwelling stent.

In this study, we audited the outcomes of different stenting techniques by a single surgeon. Retrograde cystoscopic stenting took significantly longer time due to the change of position. The presence of stent often hindered in anastomosis or got pulled into the abdomen. Antegrade stenting without guide wire also took longer time and failed in some patients due to the difficulty in negotiating distal ureter. Noh et al.[11] described antegrade stenting through angiocath cannula during robotic pyeloplasty. Antegrade stenting over guide wire through a 14-gauge IV cannula also took less time; the cannula got kinked and could not reach the site of insertion in some patients. Veress needle provided a stiff conduit wide enough to pass a 4-Fr stent over a guide wire, and the length of the needle helped to reach a point close to anastomotic site. The duration of stenting was comparable to similar studies in adults reported earlier.[12]

Several surgeons use the suction catheter as a conduit for antegrade stenting. However, it causes loss of pneumoperitoneum during stenting and Veress needle circumvents this problem. Eassa et al.[13] reported a technique similar to this using Chiba needle with good results. Hennayake[14] felt that it is up to the individual surgeon to find a safe and convenient stenting technique. “SAVVY” technique has the least stenting duration and minimum stenting failures and the authors favor this technique. When the stent does not cross VUJ, we recommend repositioning the patient for cystoscopic retrograde stenting over guide wire. However, we recommend this only for antegrade stenting failures as cystoscopy and repositioning take longer time. The limitations of this retrospective study are small sample size, exclusion of children younger than 3 years, and possible learning curve influencing outcomes in later cases. Further larger studies are likely to throw more light in finding the ideal method of stenting during LP.

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Conflicts of interest

There are no conflicts of interest.