|Year : 2014 | Volume
| Issue : 3 | Page : 92-97
Stented versus nonstented open pyeloplasty for primary ureteropelvic junction obstruction in children
Akram M Elbatarny, Mahmoud A Elafifi, Amel A Hashish, Ahmed M Elsharaby
Pediatric Surgical Unit, Faculty of Medicine, Tanta University, Tanta, Egypt
|Date of Submission||16-May-2014|
|Date of Acceptance||25-May-2014|
|Date of Web Publication||29-Oct-2014|
Akram M Elbatarny
MD, MRCSEd, 41 El Shorbagy St., Crossing with Ghayath Eldin St., Tanta 31111
The aim of the study was to compare the short-term results of stented versus nonstented open Anderson-Hynes dismembered pyeloplasty regarding operative time, hospital stay, functional outcome, and complications.
Patients and methods
Twenty-seven pediatric open Anderson-Hynes dismembered pyeloplasties were performed for primary pelviureteric junction obstruction (PUJO) by a single team at a single institution from November 2009 to October 2012. Preoperative investigations included renal function tests, urine microscopy, culture, and sensitivity, renal ultrasonography, and diethylenetriamine pentaacetic acid (DTPA). Patients were simply randomized into two groups: group I, the stented group (either nephrostent or JJ stent), and group II, the nonstented group. Outcome was analyzed with respect to operative time, hospital stay, postoperative complications, postoperative effect on hydronephrosis, and postoperative differential renal function (DRF). Minimal follow-up was 6 months.
This study included 27 pediatric patients with primary PUJO, 14 patients in group I and 13 patients in group II. The mean age was 5.72.6 years. Twelve (44.4%) cases were right sided and 15 (45.6%) were left sided; no bilateral cases were present. The mean DRF preoperatively was good in both groups (37.5% for group I vs. 35.6% in group II). There was no significant difference in operative time between both groups. The hospital stay was significantly shorter in the stented group, but this was mainly related to postoperative care policy in both groups. There was no significant difference between both groups regarding the complication rate. Postoperative DRF as well as hydronephrosis were significantly improved in both groups, but there was no statistically significant difference between both groups.
The use of stents in pyeloplasty is not justified as a routine. The overall success and complication rates are independent of whether or not to drain or of the method of drainage. Therefore, it seems that the choice depends on local circumstances and surgeon preference. A larger number of patients is needed to validate these results.
Keywords: Hydronephrosis, nonstented, pediatric ureteropelvic junction obstruction, pyeloplasty
|How to cite this article:|
Elbatarny AM, Elafifi MA, Hashish AA, Elsharaby AM. Stented versus nonstented open pyeloplasty for primary ureteropelvic junction obstruction in children. Tanta Med J 2014;42:92-7
|How to cite this URL:|
Elbatarny AM, Elafifi MA, Hashish AA, Elsharaby AM. Stented versus nonstented open pyeloplasty for primary ureteropelvic junction obstruction in children. Tanta Med J [serial online] 2014 [cited 2020 Nov 29];42:92-7. Available from: http://www.tdj.eg.net/text.asp?2014/42/3/92/143555
| Background/purpose|| |
Ureteropelvic junction obstruction is a common congenital urologic anomaly that is commonly complicated by loin pain, urinary infection, renal deterioration, stone formation, and hypertension . Open Anderson-Hynes (A-H) dismembered pyeloplasty remains the gold standard treatment of ureteropelvic junction obstruction ,. Recently, however, minimally invasive approaches have become first-line therapy at most institutions . Debate continues regarding drainage following pyeloplasty in children. Some pediatric urologists divert urine to prevent leakage, infection, and subsequent stenosis ,,,. Other surgeons think that drains may cause infection, stricture, or injury to the anastomosis or renal tissue and prolong the hospital stay ,,,. Hence, use of stents during pyeloplasty is a urological dogma. We conducted this prospective study to compare the short-term results of stented versus nonstented open A-H dismembered pyeloplasty regarding operative time, hospital stay, complications, and success rates.
| Patients and methods|| |
Between November 2009 and October 2012, 27 pyeloplasties (27 patients) were performed in the Pediatric Surgical Unit, Tanta University. The study included patients with primary pediatric PUJO. The exclusion criteria included age above 16 years, single kidney patients, secondary or recurrent PUJO, patients with differential renal function (DRF) less than 10%, patients with kidney or multiple congenital anomalies, patients with associated renal calculi, and patients with chronic debilitating disease. The preoperative work-up included renal ultrasonography (US), renal isotope scanning (DTPA), renal function tests, and urine microscopy, culture, and sensitivity (MC&S). The indications for surgery included symptomatic patients and asymptomatic patients with either severe hydronephrosis at initial evaluation (DRF>35-40% or pelvic anteroposterior diameter of >40 mm) or deterioration of initial parameters during follow-up, namely DRF and renal pelvic anteroposterior diameter or development of symptoms. The patients were randomized by the simple envelope method into two groups: group I (14 patients), the stented group, and group II (13 patients), the nonstented group.
All patients underwent standard open A-H dismembered pyeloplasty through an anterior subcostal incision and an extraperitoneal approach. After standard exposure of the pelviureteric junction (PUJ), the obstructed segment of the ureter together with redundant portion of the renal pelvis is excised and the ureter is spatulated on its lateral aspect to a distance of 0.5-1 cm. The patency of the distal part of the ureter is checked by passing a 5-6 Fr feeding tube distally. The anastomosis was accomplished using vicryl 5/0-6/0 continuous sutures. After closing the posterior layer of the ureter with the pelvis, a stent was passed in group I patients, whereas no stent was left in group II patients. We used either a JJ stent or a 5-6 Fr feeding tube as an externalized nephrostent, after making extra holes with scissors to drain the renal pelvis. Thereafter, the anterior layer is closed. In the nephrostented patients, a 16 g trocar and cannula was passed from the pelvis through the kidney tissue. A 5-6 Fr feeding tube was passed from the skin side to the bed of the kidney. The needle of the cannula was pushed into the tip of the feeding tube. With combined pushing of the feeding tube and assisted guidance of the cannula, the feeding tube was received at the inner side of the pelvis and pushed for 1.5-2 cm into the upper ureter. A perinephric drain, a Nelaton tube 16-22 Fr, was left in all patients. A Foley catheter was left in the bladder for 24 h. Antibiotics were initiated perioperatively and continued until a tube is in the body.
The nephrostent was removed after 5-7 days. The perinephric drain was removed when dry. The JJ stent was removed after 1-2 months by cystoscopy under general anesthesia (GA) as a day-case procedure.
In group I, JJ stented patients were discharged after removal of the perinephric drain. Nephrostented patients were discharged after 1-2 days then they came back for stent and drain removal on an outpatient basis. In group II, patients were discharged after removal of the perinephric drain.
The patients were followed up for early and late postoperative complications, for the fate of preoperative symptoms, and for evaluation of hydronephrosis and DRF. US was repeated at 3 and 6 months, whereas DTPA was repeated at 6 months postoperatively. The follow-up period ranged from 6 to 18 months.
Ranges were calculated as mean ± SD. Statistical comparison was performed using the χ2 -test with the package program of SPSS (version 16; SPSS Inc., Chicago, Illinois, USA) for Windows.
| Results|| |
The age of our patients at the time of operation ranged from 6 months to 15 years (mean 5.7 ± 2.6 years). Twenty (71.4%) patients were boys and seven (28.6%) were girls. Twelve (44.4%) cases were right sided and 15 (45.6%) were left sided; no bilateral cases were present.
Only three (11.1%) patients in this series were diagnosed prenatally. However, we have another three patients who were antenatally diagnosed, but two of them improved on conservative follow-up and one with bilateral multicystic dysplastic kidney died of renal failure; the three patients were excluded from the study. Ten (37%) patients presented with loin pain, three (11.1%) with vague abdominal pain, two (7.4%) with urinary tract infection (UTI), and nine (33.3%) were discovered accidentally.
The mean operative time was 93.7 ± 4.67 min in the stented group and 84.5 ± 3.76 min in the nonstented group, but the difference was not significant (P = 0.061).
The hospital stay was significantly shorter in group I (2.3 ± 1.21 days) than in the nonstented group (6.81 ± 1.34 days) (P = 0.031).
JJ stents were used in six patients, whereas nephrostents were used in eight patients. The JJ stents were removed after a mean of 35.65 ± 10.32 days. The nephrostent was removed after a mean of 5.89 ± 0.32 days. The perirenal drain was removed after a mean of 1.62 ± 0.45, 6.5±0.28, and 6.81 ± 1.34 days in JJ stented, nephrostented, and nonstented patients, respectively.
The complication rate was comparable in both groups, 14.2% in the stented group and 22.8% in the nonstented group; the difference was not significant. The nature of complications was different between the two groups. In the stented group, one (7.1%) patient suffered from UTI; it should be noted that this patient was treated preoperatively for UTI. In one (7.1%) patient, the nephrostent was slipped on day 3 postoperative, and the extrarenal drain was dry and was removed on day 7 postoperative with no further morbidity. In the nonstented group, complications occurred in three patients. One (7.6%) patient suffered from persistent urinary leakage (PUL) for 11 days and was managed conservatively. PUL was defined as leakage for more than 7 days . One (7.6%) patient had a clot retention that occurred on the second day and was managed conservatively by giving the patient furosemide. One (7.6%) patient suffered from recurrent obstruction and required a redo.
Hydronephrosis and differential renal function
There was a highly significant improvement in both hydronephrosis [Table 1] and [Table 2] and DRF in both groups, with no significant difference between the two groups. The mean preoperative DRF was 37.52 ± 2.25 and 35.63 ± 2.99 in group I and II, respectively. The mean postoperative DRF was 45.5 ± 2.24 and 44.30 ± 1.98 in group I and II, respectively.
|Table 1: Postoperative change of ultrasonography-detected hydronephrosis in group I (stented group)|
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|Table 2: Postoperative change of ultrasonography-detected hydronephrosis in group II (nonstented group)|
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| Discussion|| |
Numerous studies have investigated whether stents are needed during pediatric pyeloplasty, but the question remains unanswered and the decision remains controversial and largely surgeon dependent. Even among proponents of urinary diversion, the optimal method remains unclear ,. However, the original report by Anderson and Hynes  described a stentless procedure; currently, one can find reports supporting no stents ,,,, externalized stents (percutaneous catheter) ,,, and internalized (JJ) stents ,,. This plethora of studies proves all methods to be safe and effective, but conflicting summaries of the results have not proved any single method as superior .
The supposed advantages of stenting are maintaining alignment of the anastomosis, decreasing urinary extravasation, bypassing the transient obstruction due to edema at the anastomosis site, preventing subsequent stenosis, and enabling documenting the flow of contrast through a nephrostomy tube ,,,,. However, stents may cause infection, stricture due to pressure of a stent over the anastomosis, injury to the anastomosis or renal tissue, bleeding, dislodgement, fragmentation or migration, calculus formation, and may prolong the hospital stay. In addition, internal stents need a second hospital admission and a general anesthetic for removal ,,,,,,,,. Nonstenting allows early mobilization and freedom from draining tubes .
The preoperative data regarding age, sex, side distribution, presentation, degree of hydronephrosis, and DRF were all similar in both groups, with no significant difference. This was related to the simple randomization in the assignment of patients to any of the groups. The prenatal diagnosis of patients in our series represented a small percentage of patients compared with other studies. Three of 27 (11.1%) patients were diagnosed prenatally, and even if we add the three patients excluded from the study the percentage will be 20% (6/30), still below the percentage in other studies. The percentage was 53.9 in Elmalik et al.'s  study, 52% in Liss et al.'s  study, 40% in Hussain and Frank's  study, 47% in Φzdmir and Artikan's  study, and 70% in Woo and Farnsworth's  study. This fact needs attention and more awareness in our community; however, we are now increasingly being antenatally consulted for fetuses with hydronephrosis.
Although the operative time was longer by a few minutes in the stented than in the nonstented group, the difference was not significant. This finding is an expected finding, as the insertion of a stent whether internal or externalized is a simple maneuver that takes few minutes to complete. A similar finding was reported by Elmalik et al. .
The duration of hospitalization has become an increasingly important issue in hospitals that have limited resources and lot of patient load ,,,,. In our study, the duration of hospitalization was significantly shorter in the stented group. However, this difference was mainly related to a difference in our strategy of postoperative care. As the standard technique in our unit before conducting this study was the stented technique, we were eager to keep an eye on nonstented patients to detect any complications and manage as early as possible. Consequently, we did discharge the stented patients after 1-2 days and recalled them for removal of the stents/drains either in the outpatient clinic or as a day-case procedure, whereas we kept the nonstented patients in hospital until the perirenal drain was dry and was removed. This approach explains the difference in hospital stay, as nonstented patients could have been treated in the same way and been discharged after the acute care has passed, and catheter could have been managed at home. Some authors reported similar results with a shorter hospital stay in the stented group ,,,,. Elmalik et al.  also explained this difference on the basis of keeping patients with PUL inpatient. In contrast, some authors stated that the nonstented group had a shorter hospital stay than the stented group ,,,,,,,. Most of these series explained the longer hospital stay of the stented group on the basis of an increase in the incidence of UTI during the early postoperative period. Hence, the stented group needs parenteral antibiotics for longer periods. However, Sarin et al.  explained that, in their clinical practice, where they were dealing with not so literate section of the society, outpatient management of drainage tubes was virtually impossible. Liss et al.  discharged 81% of their nonstented patients on postoperative day 1, with an average hospital stay of 1.3 days and assured that PUL was not a cause for inpatient stay. They thought that home care of drains was possible and accepted with some peridrain inflammation. We think that this inflammation can be distressing to patients and use of tube perirenal drains may minimize it.
The incidence of postoperative complications in both groups was comparable, with no significant difference. One case of UTI occurred in a JJ stented patient, despite antibiotic prophylaxis. This case was treated preoperatively for UTI until urine C/S was negative but developed UTI again postoperatively. We had a similar case in the nonstented group who suffered from a UTI and was also treated preoperatively but did not develop a postoperative UTI. Whether this was related to the stent or not cannot be judged from only two cases. It was suggested that earlier removal of stents may reduce the risk for infection . The rate of infections increased with stent use and in patients who have PUL ,,,,. Φzdemir and Arikan  had no UTI in their stented patients where they used antibiotic prophylaxis until the stents were removed. Regarding urinary leakage, all patients of the nonstented group had temporary leakage, which ceased before the seventh day, but one patient had prolonged leakage that persisted for 11 days but ceased spontaneously and performed well in the follow-up studies, with no need for stenting. In the literature, PUL is more common in the nonstented repairs ,,,,. In Arda et al.'s  study, there was no statistically significant difference regarding urine leakage through the Penrose drain in the stented and nonstented groups. The rate of PUL was 14% in Liss et al.'s  study; all but two were managed expectantly. We had one (7.1%) stent slippage, which passed without complications or further morbidity. Castagnetti et al.  had 5% rate of stent dislodgement, which were all treated by stent removal with exceptional need for additional procedures.
Smith et al.  found also that there is no significant difference between the complications of the stented and nonstented repairs; of the 52 stented repairs, complications developed in seven (13%), of which six (12%) were potentially related to stenting. Of the 65 nonstented repairs, complications developed in 11 (17%), of which 10 (15%) were related potentially to lack of stenting . Bayne et al.  also found no significant difference in the complication rate between the stented and nonstented patients. Elmalik et al.  analyzed the nature of complications and concluded that complications related to surgical repair were significantly higher in the unsplinted group, whereas stented patients suffered only stent-related complications, namely UTI and stent migration.
The success rate of open A-H dismembered pyeloplasty varies from 94 to 100% in different series ,,,,,,,,. Our success rate in both groups was 96.3%, with only one failure requiring a redo. The failed case lied in the nonstented group and represented 7.6% of the nonstented group. Some studies reported an increased rate of secondary procedures, including redo pyeloplasty and insertion of nephrostomy or JJ tubes, in nonstented pyeloplasty ,,,. However, this conclusion cannot be drawn here from a single case of recurrence in the nonstented group. Liss et al.  stated that they cannot be certain that failure was related to nonstenting and wondered whether splinting would have prevented this complication.
The outcome of repair regarding improvement of hydronephrosis and DRF was comparable in both groups. There was significant improvement in both parameters as detected by postoperative US and DTPA, with no significant difference between both groups. This is consistent with many other reports comparing the two techniques of pyeloplasty ,. Some surgeons followed the patients only with US and performed an isotope scan only if US showed worsening hydronephrosis or if patients develop symptoms of obstruction ,,. The improvement in hydronephrosis observed in US was noted from 3 months postoperatively. Earlier improvement of hydronephrosis in stented than in nonstented patients was described ,,. Some authors denied early improvement in hydronephrosis after pyeloplasty and described improvement from 6 months to 1 year ,,. We followed up patients for a minimum of 6 months. However, some surgeons concluded that follow-up can be discontinued after 3 months . Psooy et al.  advised extending the follow-up period to 1 year to avoid repeat referrals.
Despite the comparable results of both techniques in our study and in many other studies, the rate and nature of surgery-related complications in the nonstented group as well as the rate of redo procedures, make a splinted technique preferable in the high-risk group - for example, single kidney patients, revision pyeloplasty, poor overall renal function, and renal stones ,,.
| Conclusion|| |
The use of stents in pyeloplasty in children is not justified as a routine. The success rate does not depend on whether or not to stent or on the type of stent used. Although the rate of complications is comparable in both groups, the nature of complications is different. Whether or not to stent a pyeloplasty in children relies mainly on surgeon preference and local and institutional circumstances. Stenting may be preferable in high-risk patients. However, the number of patients in the study is small and a larger number is needed to strengthen these conclusions.
The limitation of the study was the small number of patients, but this was explained by the prospective nature of the study and the cases done in a single unit in one institution.
| Acknowledgements|| |
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2]