Duplex Kidney In Children Research Articles

Comparison of proximal and distal laparoscopic ureteroureterostomy for complete duplex kidneys in children

ObjectiveTo compare efficacy of proximal and distal laparoscopic ureteroureterostomy (UU) for complete duplex kidneys in children.MethodsPatients who underwent laparoscopic UU for complete duplex kidneys between December 2016 and July 2022 were reviewed retrospectively. 71 patients who had normal lower pole moiety without vesicoureteral reflux (VUR) were recruited. All of them underwent ultrasound, voiding cystourethrography (VCUG), renal scintigraphy, and magnetic resonance urography preoperatively. Proximal laparoscopic UU was performed in 35 patients and distal laparoscopic UU in 36 patients. Double J stents were placed in normal lower pole moieties. Clinical data, including general information, diagnosis, surgical management, imaging characteristics, clinical symptoms and postoperative complications (classified according to the modified Clavien–Dindo classification), and length of stay were recorded. Measurement date comparisons between groups were performed by t test, counting date were analyzed by chi-square test.ResultsThe study consisted of 71 patients (56 females and 15 males) with complete duplex kidneys (41 in left kidney and 30 in right kidney). The patients’ mean age was 34 m (range 3–161 m) and follow-up ranged from 25 to 81 m. No significant difference was found in age and follow-up time between the two groups. Laparoscopic UU was performed in all patients successfully. The operation time of the two groups was 108.42 ± 26.95 min for distal UU vs 121.46 ± 35.15 min for proximal UU(p = 0.14). No significant difference in postoperative complications was seen between the two groups (22.2% vs 31.4%, p = 0.345). However, in terms of the grading of postoperative complications, the proximal UU group had a higher grade (3 of them had a grade of IV) and more serious complications.ConclusionsThere was no significant difference in the overall incidence of complications between distal and proximal UU. Compared with proximal laparoscopic UU, distal laparoscopic UU is easier to perform with less injury to the peripheral tissues. Postoperative complications of proximal UU are more serious and more difficult to manage. We recommend complete duplex kidney ureteral reconstruction with distal UU.

Clinical outcomes and risk factor analysis of early endoscopic puncture decompression for ureterocele associated with duplex kidney in children: a single-center retrospective study

PurposeThe aims of this study were to analyze the clinical outcomes of treating duplex system ureteroceles with early endoscopic puncture decompression and to identify the risk factors related to outcomes to help guide future work.Materials and methodsWe retrospectively reviewed the clinical records of patients with ureteroceles with duplex kidney that were treated with early endoscopic puncture decompression. Charts were reviewed for demographics, preoperative imaging, surgical indications, and follow-up data. Recurrent febrile urinary tract infections (fUTIs), de novo vesicoureteral reflux (VUR), persistent high-grade VUR, unrelieved hydroureteronephrosis, and the need for further intervention were considered unfavorable outcomes. Gender, age at surgery, BMI, antenatal diagnosis, fUTIs, bladder outlet obstruction (BOO), type of ureterocele, ipsilateral VUR diagnosed before surgery, simultaneously upper-pole moiety (UM) and lower-pole moiety (LM) obstruction, the width of ureter affiliated to UM, and maximum diameter of ureterocele were all considered potential risk factors. A binary logistic regression model was used to identify the risk factors of unfavorable outcomes.ResultsA total of 36 patients with ureteroceles related to duplex kidney underwent endoscopic holmium laser puncture from 2015 to 2023 at our institution. After a median follow-up of 21.6 months, unfavorable outcomes developed in 17 patients (47.2%). Three patients underwent ipsilateral common-sheath ureter reimplantation and one patient underwent laparoscopic ipsilateral upper to lower ureteroureterostomy combined with recipient ureter reimplantation. Three patients underwent laparoscopic upper-pole nephrectomy. Fifteen patients suffered from recurrent UTIs were treated with oral antibiotics and eight of them were diagnosed de novo VUR according to voiding cystourethrography (VCUG). In univariate analysis, patients with simultaneously UM and LM obstruction (P = 0.003), fUTIs before surgery (P = 0.044), and ectopic ureterocele (P = 0.031) were more likely to have unfavorable outcomes. Binary logistic regression analysis showed that ectopic ureterocele (OR = 10.793, 95% CI 1.248–93.312, P = 0.031) and simultaneously UM and LM obstruction (OR = 8.304, 95% CI 1.311–52.589, P = 0.025) were identified as independent factors for unfavorable outcomes.ConclusionsOur study suggested that early endoscopic puncture decompression is not a preferred but an available treatment option to release BOO or to cure refractory UTIs. It was easier to fail if the ureterocele was ectopic or simultaneously UM and LM obstruction existed. Gender, age at surgery, BMI, antenatal diagnosis, fUTIs, bladder outlet obstruction (BOO), ipsilateral VUR diagnosed before surgery, the width of ureter affiliated to UM, and maximum diameter of ureterocele were not significantly related to the success rate of early endoscopic punctures.

Clinical profile of duplex kidneys in children and its association with vesicoureteric reflux

BackgroundDuplex kidney is a relatively common renal anomaly with a wide array of associations. With routine antenatal screening it is increasingly diagnosed these days. With this study, we aim to assess the clinical profile, prevalence of vesicoureteric reflux and highlighting the need for aggressive workup and management in selected cases to prevent further renal damage.ResultsFifty-three children with duplex kidneys who attended the department of pediatric surgery at our institution from December 2016 to December 2021 were included in the study. The most common mode of presentation was urinary tract infection (58%). Fifty-three percent had an antenatally detected renal anomaly (out of these 46% were asymptomatic, 33% had UTI and 11% had other symptoms like straining, incontinence and abdominal mass). Sixty-one percent of patients were conservatively managed and 19 patients needed surgical intervention. Ureterocele was the most common condition necessitating surgery. Prevalence of vesicoureteric reflux was 60% and was comparable with other studies. Thirty-six percent of patients had renal scarring. Among the patients with scarring, 84% had VUR and 63% had febrile UTI.ConclusionDuplex kidney though a common congenital anomaly, requires a systematic evaluation to detect its various associations and a structured management protocol according to the associations. It has a high incidence of VUR which is a potentially hazardous condition which can affect the renal function if not evaluated and managed appropriately. Duplex can also be associated with obstructive conditions like PUJO, ureterocele, and ectopic megaureter which can cause rapid deterioration of renal function if not managed early enough. Though majority of the patients need only follow-up and antibiotic prophylaxis, there may be a certain sub group of patients who develop early scarring and need aggressive management. Our study aims to highlight the need to detect such patients early enough to reduce the morbidity.

The place of retroperitoneoscopic hemi-nephroureterectomy for duplex kidney in children; risk of damage to the remnant moiety and strategies to reduce the risk

To analyse the outcomes of retroperitoneoscopic upper and lower moiety hemi-nephroureterectomy (HNU) and to assess the different variables that may have an impact on outcome; remnant moiety damage, morbidity and the need for secondary surgery. Prospectively recorded data of retroperitoneoscopic HNU's performed by a single surgeon from 2005 to 2018 were analysed. Patients were split into 2 groups according to moiety affected (UMHNU and LMHNU). Clinical presentation, underlying pathology, remnant moiety DRF on renal scintigraphy, and need for further surgery were recorded. Detailed operation notes were studied regards to renal vasculature, degree of dilatation, inflammatory changes and operative difficulties encountered. Renal loss was defined as remnant moiety DRF <10% post-operatively. Change in DRF was assessed regards to the moiety, pathology and age at surgery (<1 year, 1-2 years and ≥2 years). UMHNU group was further sub-divided into 3 subgroups: ureteroceles, ectopic ureters and 'other' pathology. Statistical analysis was performed using Fishers Exact test; findings were considered statistically significant at p<0.05. 78 operations met the inclusion criteria on 75 patients (3 bilateral). There were no conversions to open, and 67% were performed as day-case procedures (53/78 patients). In 91.2% (71/78) patients the procedure was definitive in resolving pathology and symptoms. 7 patients needed further procedures after HNU, 5 for ureterocele/ureteric stump. Overall, there was remnant moiety renal loss in 5.1% (4/78) patients, all with UM surgery (3 ectopic ureters and 1 ureterocele). All 4 operations were recorded prospectively as 'difficult operations' due to grossly dilated UM ureter/pelvis measuring >2cm in diameter. 2 patients had a thinned out lower moiety (LM) sitting on top of the UM renal pelvis like a pancake with all vessels stretched over this dilated pelvis/ureter causing difficulty in accurate identification. There was intra-operative concern about some damage to LM vessels in 3 patients. Age <1year was also related to increased renal loss (2/8 patients <1 year, 1/25 patients 1-2 years, 1/45 patients ≥2 years of age P=0.005). Retroperitoneoscopic LMHNU is a safe and definitive procedure with rapid recovery and minimal scarring. UMHNU has higher rates of remnant moiety loss due to more complex renal pathology, but remains a safe, successful operation on the majority of patients. Renal damage was also related to age <1year (p=0.005) and re-operation risk after UMHNU correlated to the presence of ureterocele (p=0.003).

Laparoscopic Heminephrectomy for Duplex Kidney in Children—The Learning Curve

Objectives: Outcomes evolution during the learning curve of laparoscopic transperitoneal heminephrectomy in children with a duplex kidney.Materials and Methods: The data of 33 children, operated on between 2008 and 2017, with complicated duplex kidney, were subjected to a retrospective analysis. All patients were operated on by transperitoneal access using the laparoscopic technique. Patients were divided into two groups (1: subsequent operation 1–16, and 2: operations 17–33) to evaluate the learning curve.Results: There was no need for conversion. Total complications occurred in seven patients in Group 1 and 2 patients of Group 2 (p < 0.05). Two patients (6%) (both upper pole heminephrectomies) required reoperation to remove the ureter stump because of recurrent UTIs due to undiagnosed VUR to the stump (1 from each of Groups 1 and 2). Prolonged urine leakage (over 4 days) was observed in four patients (12%; all from group 1); in three patients, conservative treatment was successful, while the placement of a DJ catheter was needed in the fourth. A significant decrease of kidney function (>6%) in scintigraphy was observed in two of the 15 patients after the surgery. The time of surgery decreased from 140 (range 85–185) min in Group 1 to 125 (range 100–150) min in Group 2 (p < 0.05).Conclusions: Laparoscopic heminephrectomy is connected to the learning curve. Most complications occurred in the first 16 operations. With increasing experience, the time of operation decreased. In patients with reflux to the upper pole, referred for upper pole heminephrectomy, it is necessary to consider the removal of the ureter to the level of the vesicoureteral junction.

The applied anatomy of vascular variability of duplex kidney in children

Objective To study the vascular anatomy of duplex kidney and to provide a scientific basis for surgical resection of the renal segment. Methods From February 2012 to April 2018, the clinical data of 84 children with renal duplex kidney disease admitted to our hospital, were reviewed and analyzed. Among them, 75 cases (89.3%) were unilateral and 9 cases (10.7%) were bilateral. According to the preoperative CT+ CTA and the duplicated renal morphology, size, location, and anatomical relationship of the kidney segment, combined with the branches and passage of the renal artery which supplies the upper moiety, it described the blood supply of the upper renal moiety. At the same time, it analyzed various types of embryological related factors and gender differences and summarized the tips for laparoscopic surgery. Results Of the 93 duplex kidneys, 69 (74.2%) were supplied with 1 artery, and 25 (26.9%) were supplied with 2 or more arteries. Based on the shape and orifice of artery, they were divided into 3 types. The most common type was that the renal artery separated into two or more arteries near the renal parenchyma. The upper and lower renal poles were respectively supplied, which could be summarized as early branching, a total of 71 sides (76.3 %). The second type was the arteries from abdominal aorta or its branches, directly flowing into the upper renal pole, which was classified into the sub-renal artery, a total of 18 sides (19.4%). The others (4 sides, 3.3%) were less common, and most of them were a combination of the above-mentioned two types, and one of them whose upper pole was supplied by branches of adrenal artery. Based on the classification of vascular variability, no significant difference was found between males and fenmals, or left and right sides. Conclusions The upper renal moiety are mainly supplied by one branch of renal artery, and the most common type of this artery is prehilar branch, without gender difference. The determination of vascular variability before surgery can avoid bleeding during surgery and avoid accidental injury of normal blood vessels. Key words: Duplex kidney; Vascular anatomy; Laparoscopic surgery

IJU this issue

This issue deals with a wide range of clinical topics of urology, and contains five Original Articles and two Urological Notes. Although digital rectal examination (DRE) is important for considering the indication of prostate biopsy, the intrinsic lack of specificity is a weak point. Pereira-Azevedo et al. (Rotterdam, the Netherlands) assessed the level of agreement between DRE findings of two urologists and its effect on risk prediction using the DRE-based Rotterdam Prostate Cancer Risk Calculator. They showed slight differences in DRE outcomes between the two urologists, which had little impact on the performance of the Rotterdam Prostate Cancer Risk Calculator. This result is useful information when we carry out prostate biopsy. The numbers of elderly patients requiring kidney transplantation are continuously increasing in many countries. Okumi et al. (Tokyo, Japan) compared transplant outcomes among elderly (aged ≥60 years) and non-elderly recipients, and also evaluated the acceptability of elderly living donor kidney transplantation in practice after consideration of the living donor type. They showed that elderly living donor kidney transplantation seemed to provide adequate acceptable outcomes. However, they also called physicians’ attention to when elderly patients have hepatitis. Acute bacterial prostatitis is one of the major adverse events in prostate biopsy. Sadahira et al. (Okayama, Japan) investigated the prevalence of fluoroquinolone-insusceptible and/or extended-spectrum beta-lactamase-producing Escherichia coli colonizing in the male rectum before transrectal prostate biopsy using selective solid media, and also evaluated the accuracy of the selective media compared with the results of standard drug susceptibility testing. They showed the accuracy and performance of the selective media, and also showed that screening cultures before transrectal prostate biopsy using selective media seemed to be helpful for guiding antibiotic prophylaxis and decreasing the rate of post-biopsy acute prostatitis. Majkusiak et al. (Warsaw, Poland) carried out a prospective cohort study of 244 patients who underwent retropubic sling implantation to evaluate whether a phenomenon of sling migration existed after suburethral sling placement, whether this might be responsible for suboptimal sling location and persistent incontinence, and whether a link existed between sling dislocation or migration and risk factors, such as obesity or age. Their results show that suboptimal sling location appears to result from incorrect surgical technique, and should be diagnosed and treated early after the primary surgery. They also showed that sling location does not change after mid-term follow up. Various studies have reported that the use of robot-assisted surgery is feasible and safe in most pediatric cases. There is, however, a lack of evidence comparing the clinical outcomes of robot-assisted surgery with conventional open or laparoscopic techniques. Ballouhey et al. (Limoges, France) compared the outcomes of robot-assisted heminephrectomy for duplex kidney in children with those of open heminephrectomy. They showed that robot-assisted heminephrectomy in small children seems to offer comparable renal outcomes with those of its standard open surgery counterpart. They also mentioned that specific technical adjustments are necessary, which typically increase the set-up time. None declared.

Long-term functional renal outcomes after retroperitoneoscopic upper pole heminephrectomy for duplex kidney in children: a multicenter cohort study.

Retroperitoneoscopic upper pole heminephrectomy (RUHN) in duplex kidney in children remains a challenging procedure with a need for postoperative functional assessment of the remnant lower pole. We aimed to calculate the incidence of long-term functional renal outcomes in these children and examine the effect of age on those outcomes. A multicenter retrospective cohort study of 9years included all patients undergoing RUHN and evaluated by renal ultrasound (US) and dimercaptosuccinic acid (DMSA) scintigraphy pre and postoperatively. Patients were divided in two age groups of ≤12 and >12months. Standard follow-up assessed pre-, intra- and postoperative outcomes using clinical review, US and DMSA. Standard RUHN in lateral position was performed in 30 patients. Five cases were excluded (2 lacks of postoperative DMSA, 3 conversions). Indications for RUHN were non-functioning upper moieties (n=25) caused by ureterocele (n=11), ectopic distal implantation of the ureter with incontinence (n=6) or evolving severe ureterohydronephrosis (n=8). Mean age at surgery was 30±27months, operation time 116±52min and hospital stay 2.8±1days. Long-term follow-up (mean, 7.2±2.7years) with US and DMSA showed that none of the 25 patients had complete loss of lower pole renal function. Mean lower pole renal function directly related to RUHN was not significantly different after versus before RUHN for the entire cohort (n=24; 39.7±7.90% vs. 41.7±6.74%; p=0350), for the ≤12-month (n=6; 39.3±4.18 vs. 41.3±5.47; p=0.493) and the >12-month groups (n=18; 39.8±8.90 vs. 41.9±7.25; p=0.443). Four patients (17%) had partial loss of function (mean function loss, 9.3±5.85%; median age, 13months). The number and type of complications between the two age groups were not statistically different. Overall, 29% (n=7/24) of the patients presented with medium-term (17%) and long-term (17%) complications directly related to RUHN. RUHN is a demanding yet efficient technique that is safe for the lower pole at any age. Systematic postoperative DMSA is not mandatory as long as US remains normal.

Comparison of transumbilical laparoendoscopic single-site heminephroureterectomy versus conventional open surgery for children with duplex kidney

Objective To compare the outcome of transumbilical laparoendoscopic single-site surgery with conventional open surgery for duplex kidney in children. Methods Retrospective analysis of 53 cases undergone partial nephrectomy, performed in 32 girls and 21 boys with the mean age of (35.8±36.8) months from March 2013 to September 2015. The patients were divided into 2 different groups by odd and even outpatient service numbers. Group A: conventional open surgery of partial nepherectomy(n=29); Group B: transumbilical laparoendoscopic single-site Heminephroureterectomy (n=24). In group A, there were 12 boys and 17 girls, 12 of ureterocele, 7 of vesieoureteral reflux (VUR), 9 cases were of ectopie ureter and 8 of urinary tract infection (UTI), mean age was (46.0±38.3)months. In group B, there were 9 boys and 15 girls, 10 of ureterocele, 4 of VUR, 5 cases were of ectopie ureter and 7 of UTI, mean age was(20.2±28.6)months. There was no statistically significant difference in age, gender composition, affected side. Results 53 operations were done successful. There was 1 case conversion to open surgery and 2 cases added an additional port besides the umbilicus in Group B, and all occurred in the early stage of the study. Compared Group A with Group B, the operation time[(137.0±28.8) min vs.(167.3±43.7) min, P=0.006]; blood loss[(45.7±28.8) ml vs.(23.2±43.7) ml, P=0.134]; blood transfusion (6 vs.4, P=0.709); time of resumption to a regular diet[(1.4±1.5) d vs.(1.4±1.1) d, P=0.785]; time of indwelling drainage tube [(5.1±1.6) d vs.(4.1±2.0) d, P=0.200]; postoperative hospital stay [(8.6±2.0) d vs.(8.6±2.0) d, P=0.725]. The mean time of follow up after surgery is 18.2 months (2-31 months). Complications after surgery between group A and B included hypertension (2 vs. 0, P=0.495); urinary tract infection (2 vs.3, P=0.824), distal ureteric stump(DVS) (0 vs.1, P=0.453) and renal functional loss (1 vs.0, P=1.000). Conclusion The transumbilical laparoendoscopic single-site heminephrectomy is safe, feasible, effective in experienced pediatric urologic surgeons and high volume centres. It can reach or even exceed the effect of traditional open surgery. After the learning period, the operation time was significantly shortened, and can reach or be lower than open surgery time. Transumbilical laparoendoscopic single-site surgery (LESS) has the advantages of reduce the surgical trauma and better cosmetic results. Key words: Laparoendoscopic; Duplex kidney; Heminephroureterectomy; Laparoendoscopic single-site surgery

Laparoscopic Versus Open Upper Pole Heminephroureterectomy for the Treatment of Duplex Kidneys in Children

To evaluate the safety and feasibility of laparoscopic upper pole heminephroureterectomy (HNU) in pediatric patients with duplex kidneys in comparison with open surgery. From 2007 to 2011, 27 patients underwent HNU. A dimercaptosuccinic acid (DMSA) isotope scan revealed hypofunctioning of ipsilateral moieties in all cases. The patients were divided randomly into laparoscopic HNU (LHNU) and open surgery HNU (OHNU) groups. LHNU was performed by the transperitoneal approach in 10 girls and 5 boys with a mean age of 33 months (range, 9-108 months). All procedures were performed using three or four ports. Open surgery was performed in 10 girls and 2 boys with a mean age of 29 months (range, 7-174 months) by the retroperitoneal approach in all cases. Follow-up included ultrasound and DMSA. Mean operative time in the LHNU and OHNU groups was 148 minutes (range, 100-220 minutes; 95% confidence interval [CI] 129-167 minutes) and 124 minutes (range, 100-150 minutes; 95% CI 115-133 minutes), respectively. In the LHNU and OHNU groups, mean analgesic requirement was 2.8 days (range, 2-4 days; 95% CI 2.4-3.2 days) and 3.7 days (range, 3-5 days; 95% CI 3.3-4.1 days), and mean hospital stay was 4.0 days (range, 2-8 days; 95% CI 3.2-4.8 days) and 5.1 days (range, 3-8 days; 95% CI 4.3-5.9 days), respectively. No intraoperative or major postoperative complications occurred. No conversion to open surgery was necessary in the LHNU group. Statistical analysis showed no statistical significant difference (P>.05) in the operating time between groups, whereas differences in the mean hospital stay (P=.048) and analgesic requirements (P=.005) were significant. The function of the remnant pole was preserved in all patients. Follow-up ultrasound showed asymptomatic cystic structures in 1 patient. The laparoscopic upper pole HNU is a safe and feasible procedure, even in infants. It is associated with minimal morbidity, and the operative time is acceptable and not significantly longer in comparison with the open approach. LHNU reduces analgesic requirements and hospital stay. In our opinion it should be the preferred option for HNU in children.

Laparoscopic Transperitoneal Heminephrectomy for Duplex Kidney in Infants and Children: A Comparative Study

Evaluation of the feasibility, safety, and outcome of laparoscopic heminephrectomy for duplex kidneys in children above and below the age of 12 months. The transperitoneal surgical technique included division of the parenchyma with a sealing device (LigaSure™; Covidien, Mansfield, MA) and amputation of the ureter as low as possible. A follow-up study was performed. Patients' records were analyzed retrospectively for operative details and postoperative complications. Long-term outcome was assessed during follow-up visits and a final telephone interview. Outcome was compared between two groups: Group 1 (G1), age at surgery<12 months; Group 2 (G2), age at surgery >12 months. Between July 2004 and September 2012, in total, 22 laparoscopic heminephrectomies (20 upper poles and 2 lower poles) were performed in 20 patients (G1, 12 cases; G2, 10 cases). A mean (range) age at surgery was 7.1 (3-11) months in G1 and 49.4 (15-128) months in G2. Mean (range) operative time was 152 (81-220) min in G1 and 197 (90-265) min in G2 (P=.06). All procedures were completed laparoscopically. Major postoperative complication was one urinoma in G1, which was surgically revised. Mean hospital stay was 3.6 days (G1, 4.0 days; G2, 3.1 days). During long-term follow-up (median, 5.2 years) febrile urinary tract infections occurred to the same extent in both groups (G1, 1/12; G2, 2/10; P=.57). Laparoscopic transperitoneal heminephrectomy for duplex kidneys is safe and feasible even in small infants. Long-term results are excellent irrespective of the patient's age.

Complications and Late Outcome in Transperitoneal Laparoscopic Heminephrectomy for Duplex Kidney in Children

We report our experience with laparoscopic heminephrectomy (LH) in children with duplex kidneys, emphasizing complications and late outcomes, and including anatomic and functional aspects. We retrospectively reviewed medical data of 28 children with a duplex kidney who underwent LH. Complications were evaluated according to the Savata and Clavien classiffication systems. Nineteen upper (67.8%) and 9 (32.1%) lower moieties were removed. All laparoscopic procedures were completed as planned without conversion. There were three (10.5%) cases of intraoperative bleeding successfully controlled by compression with gauze. Complications after surgery included two urinomas (7%), one intra-abdominal hematoma (3.5%), and two cases of complete functional loss (7%) because of torsion of the remnant upper pole. In six (21.4%) cases, a cyst at the resection margin of the kidney remnant was found. The function of the remnant pole was preserved in 23 (82.1%) cases and decreased in approximately 5% in 3 (10.5%). The anatomic and functional outcomes of LH must be evaluated with imaging studies and nuclear scintigraphy to rule out structural abnormalities and functional impairment. An extensive dissection in the lower pole LH can lead to the upper moiety torsion after surgery.

Laparoscopic management and outcomes in non-functioning moieties of duplex kidneys in children

Retroperitoneal laparoscopic hemi-nephrectomy (RLHN) is a well tolerated, minimally invasive, although technically demanding, procedure for children with a non-functioning moiety in a duplex kidney. There is very little published data on the long-term follow up of such patients. We collected data to assess outcomes from our experience. Data were retrospectively gathered on all patients who underwent RLHN at our institution between February 2003 and July 2008. Follow-up ultrasounds were obtained in all patients. RLHN was performed in 42 patients. All had a non-functioning moiety of a duplex kidney and in addition recurrent urinary tract infections (n=36), incontinence (n=5) or vesico-ureteric reflux (n=1). Median age at surgery was 3 years, 7 months (4 months-13 years, 10 months). One patient required conversion to open procedure due to low (pelvic) kidney. The median operating time was 90min (45-150min). Urine leak developed postoperatively in one patient and loss of function of the remaining moiety occurred in another patient. They were followed up for a median period of 11 months (1-51 months). RLHN is a feasible and safe technique for the experienced paediatric laparoscopic urologist. Results compare very favourably with open heminephrectomy in terms of operating time and outcomes. Long-term follow up is mandatory.

Laparoscopic partial nephrectomy in infants and children. how difficult is it ?

Aim Despite the widespread use of laparoscopy for renal surgery in children, there are few large series of laparoscopic partial nephrectomies reported in the paediatric population. We report our experience with laparoscopic hemi-nephrectomy in duplex kidneys in children. Patients and methods Since 1993, 41 children underwent laparoscopic hemi-nephrectomy (39 retroperitoneoscopic, 2 transperitoneal) in our institution, including 30 upper-pole nephrectomies (UPN) and 11 lower-pole nephrectomies (LPN). Median age at surgery was 6.2 months (range 1.5-89), including 27 infants. The patient was placed in lateral position in 31 and prone in the last 10. Follow-up was based on clinical review and renal ultrasound. Results Median duration of surgery was 130 min (71-215). Ten procedures (25%) were converted into open surgery, mostly at the beginning of the experience (8 during the first 20 cases). Among 4 converted LPN, 3 were converted for difficulties during parenchymal section, all before acquisition of the Harmonic scalpel. Six UPN were converted for difficulties of visualization of vascular anatomy, including 3/6 with a dilated ureter (>15mm) and 2/6 with an accidental pneumoperitoneum. None of the 8 UPN performed in children older than 1 year were converted. Median follow-up was 14 months (4-125). We observed one case (case #4) of functional loss of the remaining lower moiety. There were no case of postoperative urine leak. Conclusions This study shows a high conversion rate during laparoscopic hemi-nephrectomy in children, that may decrease with experience and the use of modern instrumentation enabling easier parenchymal section. Retroperitoneoscopic UPN remains a challenging procedure, especially in small infants with very dilated collecting systems. The possibility of vascular damages to the remaining moiety warrants a very cautious dissection of the renal pedicle and should lead to conversion when clear visualization of vascular anatomy is not ascertained.

The incidence and importance of renal duplication

The excretory urograms performed on 1716 children and 3480 adults have been examined to find the incidence and complications of renal duplication. Ninety-five patients with duplication were found, unilateral in 79 and bilateral in 16 patients. It was equally common on each side and twice as common in females as in males. Non-duplex kidneys had a mean of 9.4 calyces and duplex kidneys had a mean 3.7 upper and 7-6 calyces in lower moieties. In patients without renal disease and with unilateral duplication the two kidneys were equal in size in 39%, and the duplex was smaller in 10%. Twenty-seven per cent of the duplex kidneys examined showed evidence of disease compared to 3% of the non-duplex kidneys-a significant difference (P less than 0-001). Saddle reflux is the only abnormality unique to duplication and was seen in one patient. Extravesical ectopic ureter and ureterocoeles are known to be associated with renal duplication, but in this series ureterocoeles were found only on the non-duplex side. The duplex kidney in children is more susceptible to reflux than is the non-duplex kidney, and this leads to both ureteric and pelvi-calyceal dilation, and to chronic pyelonephritis in the duplex side in those children who develop urinary tract infections. Chronic pyelonephritis was found in 22% of patients under 15, significantly more often than in adults (P less than 0-001), although the incidence of duplication was unchanged. It is concluded that there is no real increase in the number of children with duplex kidneys having urinary tract infections, and the vast majority of duplex kidneys do not become diseased.