Preliminary evidence of a relationship between sleep spindles and treatment response in epileptic encephalopathy.

OBJECTIVE: Epileptic encephalopathy with spike-wave activation in sleep (EE-SWAS) is a challenging neurodevelopmental disease characterized by abundant epileptiform spikes during non-rapid eye movement (NREM) sleep accompanied by cognitive dysfunction. The mechanism of cognitive dysfunction is unknown, but treatment with high-dose diazepam may improve symptoms. Spike rate does not predict treatment response, but spikes may disrupt sleep spindles. We hypothesized that in patients with EE-SWAS: (1) spikes and spindles would be anti-correlated, (2) high-dose diazepam would increase spindles and decrease spikes, and (3) spindle response would be greater in those with cognitive improvement. METHODS: Consecutive EE-SWAS patients treated with high-dose diazepam that met the criteria were included. Using a validated automated spindle detector, spindle rate, duration, and percentage were computed in pre- and post-treatment NREM sleep. Spikes were quantified using a validated automated spike detector. The cognitive response was determined from a chart review. RESULTS: Spindle rate was anti-correlated with the spike rate in the channel with the maximal spike rate (p = 0.002) and averaged across all channels (p = 0.0005). Spindle rate, duration, and percentage each increased, and spike rate decreased, after high-dose diazepam treatment (p ≤ 2e-5, all tests). Spindle rate, duration, and percentage (p ≤ 0.004, all tests) were increased in patients with cognitive improvement after treatment, but not those without. Changes in spindle rate but not changes in spike rate distinguished between groups. INTERPRETATION: These findings confirm thalamocortical disruption in EE-SWAS, identify a mechanism through which benzodiazepines may support cognitive recovery, and introduce sleep spindles as a promising mechanistic biomarker to detect treatment response in severe epileptic encephalopathies.

Preliminary evidence of a relationship between sleep spindles and treatment response in epileptic encephalopathy.

Objective: Epileptic encephalopathy with spike wave activation in sleep (EE-SWAS) is a challenging neurodevelopmental disease characterized by abundant epileptiform spikes during non-rapid eye movement (NREM) sleep accompanied by cognitive dysfunction. The mechanism of cognitive dysfunction is unknown, but treatment with high-dose diazepam may improve symptoms. Spike rate does not predict treatment response, but spikes may disrupt sleep spindles. We hypothesized that in patients with EE-SWAS: 1) spikes and spindles would be anticorrelated, 2) high-dose diazepam would increase spindles and decrease spikes, and 3) spindle response would be greater in those with cognitive improvement. Methods: Consecutive EE-SWAS patients treated with high-dose diazepam that met criteria were included. Using a validated automated spindle detector, spindle rate, duration, and percentage were computed in pre- and post-treatment NREM sleep. Spikes were quantified using a validated automated spike detector. Cognitive response was determined from chart review. Results: Spindle rate was anticorrelated with spike rate in the channel with the maximal spike rate ( p =0.002) and averaged across all channels ( p =0.0005). Spindle rate, duration, and percentage each increased, and spike rate decreased, after high-dose diazepam treatment ( p≤ 2e-5, all tests). Spindle rate, duration, and percentage ( p ≤0.004, all tests) were increased in patients with cognitive improvement after treatment, but not those without. Changes in spike rate did not distinguish between groups. Interpretation: These findings confirm thalamocortical disruption in EE-SWAS, identify a mechanism through which benzodiazepines may support cognitive recovery, and introduce sleep spindles as a promising mechanistic biomarker to detect treatment response in severe epileptic encephalopathies.

Ictal EEG in sunflower syndrome: Provoked or unprovoked seizures?

Sunflower syndrome (SS) is a rare, photosensitive epilepsy characterized by an attraction to light and highly stereotyped seizures with associated hand-waving (HW). It is controversial whether HW is part of the seizure or a provoking factor; therefore, we aimed to characterize the ictal electroencephalogram (EEG) in patients with SS. Video-EEG (vEEG) and charts of five patients with SS with HW during vEEG from Massachusetts General Hospital's Pediatric Epilepsy Program were reviewed and analyzed. In four out of five patients, the ictal EEG showed high amplitude (500-700 µV) 3-4 Hz generalized spike/polyspike-and-slow wave discharges, lasting 1.63-24.41 s. One hundred and twelve of 126 HW episodes, correlating to epileptiform activity (vEEG), had a lag time of less than 1.00 s (88.89%) between onset of HW and appearance of epileptiform activity. This suggests that HW does not induce seizure activity. Awareness of the ictal EEG features of this syndrome is important, as patients are frequently described as "self-inducing" their seizures.

Neferine inhibits LPS-ATP-induced endothelial cell pyroptosis via regulation of ROS/NLRP3/Caspase-1 signaling pathway.

BACKGROUND: Oxidative stress-induced endothelial dysfunction and pyroptosis play an important role during chronic kidney disease (CKD) progression. Neferine, which is an alkaloid ingredient from the lotus seed embryo, has many biological actions such as anti-inflammatory, anticancer and antioxidant. However, the role of neferine in endothelial cell pyroptosis and the involved mechanism remain obscure. The aim is to probe the protective effects of neferine on cell pyroptosis and the involved underlying mechanism. METHODS: After the HUVECs were primed with neferine treatment for 2 h prior to LPS and ATP exposure for 24 h, the cell proliferation was determined by BrdU; the cell LDH release was detected by LDH kits; the levels of intracellular ROS, MDA and SOD were tested by detection kits; Caspase-1 activity kit was used to determine caspase-1 activity; the contents of NLRP3, ASC, caspase-1, IL-1ß, IL-18 and GSDMD were tested by RT-PCR and western blot. RESULTS: We found that neferine could inhibit LPS-ATP-induced oxidative stress and the activation of NLRP3 inflammasome signaling, and increased the endothelial cell viability and SOD production. siRNA which mediated the knockdown of NLRP3 promoted the neferine-induced inhibition effects of cell pyroptosis. Furthermore, these neferine-induced effects were reversed by the over-expression of NLRP3. CONCLUSIONS: Our findings indicated neferine may reduce ROS by anti-oxidation and inhibit LPS-ATP-induced endothelial cell pyroptosis via blocking ROS/NLRP3/Caspase-1 signaling pathway, which provides the evidence for therapeutic effect in CKD.

Retroperitoneoscopic upper pole nephroureterectomy in duplex kidney: focus on the role of dilated upper pole ureter.

PURPOSE: To describe our technique and experience with retroperitoneoscopic upper pole nephroureterectomy in duplex kidney, focusing on the role of dilated upper ureter. MATERIALS AND METHODS: From November 2004 to August 2011, retroperitoneoscopic upper pole nephroureterectomy was performed in 31 patients with a duplex kidney by a single, experienced laparoscopic surgeon. We developed our own surgical technique to suit this technically challenging procedure. Follow-up studies were performed using renal ultrasonography, intravenous urography (IVU) and/or dimercaptosuccinic acid (DMSA) renal scan in all patients at 3 months postoperatively and annually thereafter. RESULTS: All procedures were completed laparoscopically without conversion to open surgery and blood transfusion. The mean operative time was 106 (90-157) min. The estimated blood loss was < 50 mL in all cases. The mean postoperative hospital stay was 4.2 (3-7) days. Perioperative complications were limited to 1 case of peritoneal tear during a procedure and 1 case of transient postoperative fever. No major intraoperative and postoperative complication occurred. With the mean follow-up period of 41 months (range 3 to 80), no case was observed to have functional loss of the remaining lower moiety on postoperative IVU or DMSA renal scan. CONCLUSION: Retroperitoneoscopic upper pole nephroureterectomy using our technique is safe and effective.

Laparoendoscopic single-site retroperitoneoscopic adrenalectomy for pheochromocytoma: case selection, surgical technique, and short-term outcome.

PURPOSE: To present our experience with case selection and operative skills of laparoendoscopic single-site (LESS) retroperitoneoscopic adrenalectomy for pheochromocytoma and evaluate its feasibility. PATIENTS AND METHODS: Between June 2011 and December 2012, we performed LESS retroperitoneoscopic adrenalectomy for 16 patients with pheochromocytoma. In all patients, the diameter of the pheochromocytoma was less than 4.0 cm. During the operation, a single-port access was inserted through a 2.5-3.0 cm transverse incision below the tip of the 12th rib. Internally, the operative procedure duplicates the conventional retroperitoneoscopic adrenalectomy for pheochromocytoma. RESULTS: No conversions to open surgery or standard laparoscopy with additional trocars were necessary. The mean operative duration was 68.1 minutes (range 41-125 min). The mean blood loss was negligible (<50 mL), and no patient needed blood transfusion. Intraoperative hypertension (SBP>180 mmHg) occurred in 12.5% (2/16) of the patients. No patient had sustained hypertension, and none experienced intraoperative hypotension (systolic blood pressure <80 mm Hg). The only postoperative complication was one case of pneumonia successfully treated with antibiotics. The average postoperative hospital stay was 3.1 days (range 2-5 days). All patients left the hospital with a good cosmetic appearance. CONCLUSIONS: In properly selected patients, LESS retroperitoneoscopic adrenalectomy is a feasible and safe procedure for pheochromocytoma.

Retroperitoneal laparoendoscopic single-site ureterolithotomy for upper ureteral stone disease.

OBJECTIVE: The aim of this article was to present this group's clinical experience with retroperitoneal laparoendoscopic single-site (LESS) ureterolithotomy for the management of upper ureteral stones in selected patients. MATERIAL AND METHODS: From May 2011 to November 2012, retroperitoneal LESS ureterolithotomy was performed in 22 patients at Xiangya Hospital. During the operation, a transverse skin incision was made approximately 2.5 cm in length along the lower margin of the 12th rib at the midaxillary line, and a single port was inserted. Standard steps of a multisite retroperitoneoscopic ureterolithotomy with a combination of conventional straight instruments and bent instruments were performed. RESULTS: All cases were completed successfully without conversion to standard laparoscopy or open surgery. No additional ports or expensive flexible instruments were required. Overall, mean operative time was 98.5 min (range 76-174 min) and mean estimated blood loss was 33.4 ml (range 18-53 ml). Mean hospital stay after surgery was 3.7 days (range 3-5 days). One patient had fever postoperatively due to an Escherichia coli urinary tract infection, which resolved with appropriate antibiotic therapy. There were no major complications. The mean follow-up period was 10.5 months (range 3-21 months). All patients were asymptomatic and did not exhibit signs or symptoms of obstruction or stricture. CONCLUSIONS: Retroperitoneal LESS ureterolithotomy is a feasible, safe and effective surgical method for the treatment of upper ureteral stones in select patients. Prospective studies based on more patients are needed to evaluate further its advantages over conventional laparoscopic ureterolithotomy.

Transperitoneal mini-laparoscopic pyeloplasty and concomitant ureteroscopy-assisted pyelolithotomy for ureteropelvic junction obstruction complicated by renal caliceal stones.

OBJECTIVE: To present our experience of combining transperitoneal mini-laparoscopic pyeloplasty (mini-LP) and concomitant ureteroscopy-assisted pyelolithotomy (U-P) for ureteropelvic junction obstruction (UPJO) complicated by renal caliceal stones in the same session. METHODS: Between May 2007 and December 2011, mini-LP and concomitant U-P was performed in nine patients with UPJO and ipsilateral renal caliceal stones. Stone location and burden were preoperatively assessed. After pyelotomy with appropriate length (about 4 mm), a 16-Fr catheter sheath replaced the uppermost or lowermost laparoscopic trocar and was introduced directly into the renal pelvis under the guidance of a guide wire and laparoscopic vision. A 7.5F rigid ureteroscopy passed through the catheter sheath into the plevis. Intracorporeal lithotripsy and/or pressure irrigation via a pump was used for caliceal stone removal. Subsequently, laparoscopic pyeloplasty was performed in a standard fashion. Postoperative imaging was assessed. RESULTS: The calculi sizes ranged from 2 to 11 mm (mean, 7.1 mm) and an average of 3 stones per patient was removed (range, 1 to 6 stones). Complete stone clearance confirmed by postoperative imaging was achieved in all patients. Mean operative time was 210 minutes, and estimated blood loss was 20 mL. Mean hospital stay was 5 days (4-7). Stent was removed after 4-8 weeks. No intraoperative or postoperative complications were noted during a mean follow-up of 18.5 months (range, 6 to 24 months). CONCLUSIONS: Mini-LP and concomitant U-P are simple and effective alternatives for the simultaneous management of UPJO complicated by coexisting ipsilateral renal caliceal stones.

Feasibility and safety of retroperitoneal laparoendoscopic single-site dismembered pyeloplasty: a clinical report of 10 cases.

OBJECTIVE: To retrospectively review our experience with respect to evaluating the feasibility and safety of laparoendoscopic single-site (LESS) dismembered pyeloplasty for ureteropelvic junction obstruction (UPJO) through a retroperitoneal approach. PATIENTS AND METHODS: Between March 2011 and January 2012, 10 consecutive patients underwent LESS retroperitoneoscopic dismembered pyeloplasty performed by one experienced laparoscopic surgeon at our institution. A single-port access was inserted through a 2.5-cm transverse skin incision below the 12th rib along the midaxillary line. Standard steps of the multisite retroperitoneoscopic Anderson-Hynes dismembered pyeloplasty technique using conventional instruments or a combination of conventional and bent laparoscopic instruments were performed. Follow-up studies were conducted by intravenous urography (IVU), diuretic renal scan, and renal ultrasonography. RESULTS: LESS retroperitoneoscopic dismembered pyeloplasty was successful in 9 patients, whereas 1 required four-port retroperitoneoscopic conversion because of difficulties in remaining in the retroperitoneal space due to a peritoneal tear during the procedure. The mean operative time was 148.4 minutes (range, 103-210 minutes). The mean estimated blood loss was 31 mL (range, 10-70 mL), and the mean postoperative hospital stay was 5.7 days (range, 3-13 days). Intraoperative complications were limited to the one case of peritoneal tear. An aberrant crossing vessel was noted in 4 patients, and transposition was not required in these patients. Urine leakage occurred in 1 patient postoperatively and was successfully treated by conservative management. The mean follow-up period was 6.2 months (range, 5-10 months). Satisfactory drainage with decreased hydronephrosis on IVU, diuretic renal scan, and renal ultrasonography was observed in all cases at the 3-month imaging studies. CONCLUSIONS: In experienced hands, LESS retroperitoneoscopic dismembered pyeloplasty is a feasible and safe alternative for correcting UPJO, although it remains technically challenging. The long-term outcome awaits further studies.

Treatment of symptomatic primary obstructive megaureter by laparoscopic intracorporeal or extracorporeal ureteral tapering and ureteroneocystostomy: experience on 11 patients.

PURPOSE: To present our experience and the feasibility with laparoscopic ureteral reimplantation using ureteral tapering (intracorporeal or extracorporeal) for symptomatic primary obstructive megaureter. PATIENTS AND METHODS: Between June 2005 and September 2010, 11 patients (mean age: 33.2 years) with symptomatic congenital primary obstructive megaureter underwent laparoscopic reconstruction. All patients underwent laparoscopic intracorporeal or extracorporeal ureteral tailoring and ureteroneocystostomy by the same surgical team. The relevant perioperative details and complications were recorded. RESULTS: No open conversions or blood transfusions were necessary. Total mean operative time was 142 minutes (range 109-227 min). The mean operative time for the five patients with intracorporeal tailoring was 154 minutes (range 121-227 min), compared with 125 minutes (range 109-165 min) for the six patients with extracorporeal tailoring. The mean blood loss was 45 mL (range 30-85 mL) for all cases. Mean postoperative hospital stay was 6.4 days (range 5-8 days). In one patient, urinary leakage was noted immediately postoperatively; it disappeared spontaneously with conservative treatment by postoperative day 7. Average follow-up was 18 months (range 13-24 mos). Follow-up renal ultrasonography and intravenous urography confirmed decreased hydronephrosis with good drainage. Nonobstructed clearance was also demonstrated using diuretic renography in all cases. CONCLUSIONS: Laparoscopic intracorporeal or extracorporeal ureteral tailoring and ureteroneocystostomy is a feasible and reproducible procedure. Follow-up revealed satisfactory objective and subjective outcomes.

Retroperitoneal laparoendoscopic single-site adrenalectomy: our initial technical experience.

OBJECTIVE: We performed retroperitoneal laparoendoscopic single-site (LESS) adrenalectomy using a homemade multi-access platform to evaluate the feasibility and safety of this technique and to share our initial experiences. PATIENTS AND METHODS: Since March 2011, 40 patients underwent retroperitoneal LESS adrenalectomy. A single incision of 2.5-3 cm was made under the 12th rib on the midaxillary line on the affected side. Next, a homemade multi-access platform was inserted through that incision, and a combination of lengthened curved and conventional rigid instruments was used for handling. The procedure was performed mainly according to the procedure for conventional laparoscopic retroperitoneal adrenalectomy. RESULTS: For 1 patient with pheochromocytoma, one additional trocar was used because the peritoneum was damaged. Surgery was successfully completed in all other patients without conversion to conventional laparoscopic or open surgery. CONCLUSIONS: Retroperitoneal LESS adrenalectomy is feasible; although initial technical adjustments are inevitable, some useful techniques are effective in simplifying the procedure.

Retroperitoneal laparoendoscopic single-site ureterolithotomy and ureteroureterostomy for retrocaval ureter with ureteral calculus: first case report.

A 53-year-old man presented with a 6-month history of intermittent right flank pain. Radiological imaging confirmed the diagnosis of retrocaval ureter (RCU) and ureteral calculus. Retroperitoneal laparoendoscopic single-site surgery (LESS) ureterolithotomy and ureteroureterostomy was successfully performed. The operative time was 185 min and the blood loss was approximately 20 ml. The patient's postoperative course was uneventful. Postoperative analgesia was not needed. The patient was discharged on the third postoperative day. The drain and double-J stent were respectively removed at 1 and 8 weeks postoperatively. At the 3-month follow-up, nuclear scan showed no evidence of obstruction of the right kidney and the patient also remained symptom free. It may be concluded that retroperitoneal LESS repair for RCU is a feasible and safe procedure, which can be considered as a option for the management of RCU even if it is complicated by the presence of a ureteral calculus.

Retroperitoneal laparoendoscopic single-site simple nephrectomy: initial experience.

PURPOSE: To present our early experience with retroperitoneal laparoendoscopic single-site (LESS) simple nephrectomy. PATIENTS AND METHODS: A total of 16 patients with benign nonfunctioning kidney underwent retroperitoneal LESS nephrectomy by one experienced laparoscopic surgeon. A single-port access was inserted through an approximately 3-cm lumbar incision made below the 12th rib along the midaxillary line. Standard steps of multisite retroperitoneoscopic nephrectomy technique with a combination of conventional and bent laparoscopic instruments were performed. RESULTS: Retroperitoneal LESS nephrectomy was performed in 15 cases successfully. The procedure of one patient (genitourinary tuberculosis) needed conversion to open surgery because of the severe adhesions surrounding the kidney, which resulted in failure to progress. Overall, the mean operative time was 85 (75-140) minutes, and estimated blood loss was 56 (20-110) mL. The mean time to resume oral diet was 1.5 days. The mean postoperative hospital stay was 4 (3-5) days. Perioperative complications were limited to one case of transient postoperative fever. No major intraoperative and postoperative complication occurred. CONCLUSIONS: Retroperitoneal LESS nephrectomy performed by an experienced laparoscopic surgeon is feasible and safe, offering improved cosmesis, although it remains technically challenging. Retroperitoneal LESS nephrectomy should be selectively used in terms of patients' specific conditions.

Retroperitoneoscopic decortication of symptomatic peripelvic renal cysts: Chinese experience.

OBJECTIVES: To report our single-center experience of retroperitoneoscopic renal cyst decortication in the treatment of symptomatic peripelvic renal cysts. METHODS: From January 2003 to July 2010, 36 patients with symptomatic peripelvic renal cysts, mean size 7.9 cm (range 5.8-12), underwent retroperitoneoscopic cyst decortication. The patients with complex renal cysts were excluded. Of the 36 patients, 2 had undergone an unsuccessful previous cyst aspiration. The Wong-Baker pain scale was used to assess the preoperative and postoperative pain scores. Radiologic success was defined as no recurrence on the most recent computed tomography scan. RESULTS: Retroperitoneoscopic renal cyst decortication was successful in all patients. No open conversions or transfusions were necessary. The mean operative time was 159 minutes (range 113-189), and the mean estimated blood loss was 55 mL (range 20-78). The mean hospital stay was 3.5 days. In 2 patients, the collecting system was entered, and a double-J stent, which drained the pelvis for 4 weeks, was placed at the end of the procedure. No evidence of urine leakage was found postoperatively. Symptomatic success was achieved in 35 (97.2%) of the 36 patients, and imaging-proved success was achieved in 34 (94.4%). The mean follow-up period was 48 months (range 3-89). CONCLUSIONS: Our results have confirmed that retroperitoneoscopic peripelvic renal cyst decortication is a safe, feasible, and effective procedure. It offers a favorable minimally invasive treatment option for symptomatic peripelvic renal cysts, although it remains technically challenging.

Treatment of retrocaval ureter by retroperitoneal laparoscopic ureteroureterostomy: experience on 12 patients.

OBJECTIVE: To present our experience and the feasibility of retroperitoneal laparoscopic ureteroureterostomy (LUUS) for treatment of retrocaval ureter (RCU). PATIENTS AND METHODS: A total of 12 patients with RCU underwent LUUS. To evaluate the retrocaval segment, we calibrated retrocaval segment by a number 8F catheter segment before laparoscopy. A three-port, finger-dissecting removal of the retroperitoneal fat, retroperitoneal approach was used. In all 12 cases, after the ureter had been released from the inferior vena cava (IVC), the ureter was transected at the lower part of the dilated ureter and positioned anterior to the IVC. A tension-free ureteroureteral anastomosis was completed with the intracorporal freehand suturing techniques. Follow-up studies were performed with intravenous urography and renal ultrasonography at 3 and 6 months postoperatively. RESULTS: All operations were laparoscopically completed with no open conversion. The mean operating time was 112 minutes (range 89-158), and the mean anastomosis time was 42 minutes, for all cases. The mean blood loss was 35 mL (range 21-60). The retrocaval segments of the ureter were resected in 2 of 12 cases, because the 8F catheter could not negotiate the segment. No intraoperative complications occurred. Hydronephrosis in all patients was decreased substantially after surgery, and all patients were symptom free. CONCLUSION: Our results have demonstrated that retroperitoneal LUUS was a safe and effective procedure, and an excellent minimally invasive treatment option for RCU.

Technical modifications of double-J stenting for retroperitoneal laparoscopic dismembered pyeloplasty in children under 5 years old.

Both antegrade stenting and retrograde stenting for retroperitoneal laparoscopic dismembered pyeloplasty in children have many disadvantages. In this work, we tried using an alternative technique of modified antegrade (MAG) double-J stenting for retroperitoneal laparoscopic dismembered pyeloplasty in children under 5 years old, analyzed our results using the conventional antegrade (CAG) and the MAG techniques of stent insertion for this procedure, and reported our experience with these techniques. Between December 2002 and July 2010, 77 children under 5 years old with ureteropelvic junction obstruction underwent retroperitoneal laparoscopic dismembered pyeloplasty. CAG and MAG double-J stenting were attempted, in the first 36 cases (mean age 27.1 months) and the following 41 cases (mean age 25.4 months), respectively. The stents were removed 4-6 weeks later via cystoscopy. Follow-up studies were performed with ultrasonography and intravenous urography at 3 and 12 months postoperatively. The results showed that successful stent placement without malpositioning was achieved in 31 of 36 (86%) and all 41 (100%) cases, in the CAG and MAG groups, respectively. The common factor of unsuccessful stent was the inability to across the ureterovesical junction. The mean stent insertion time was 10 min 54 s and 12 min 46 s in the CAG and MAG groups, respectively. The mean operating time was 176 min and 185 min in the CAG and MAG groups, respectively. No stent malpositioning occurred in the MAG group; in the CAG group, two children had a malpositioned stent in the distal ureter and one child presented with a severe hematuria. Twelve months follow-up showed no new onset of hydroureteronephrosis and hydronephrosis. Thus we concluded that the MAG double-J stenting seems more reliable than CAG stenting for retroperitoneal laparoscopic dismembered pyeloplasty in children under 5 years old, with greater success and lower complication rates.

[Retroperitoneoscopic dismembered pyeloplasty for pediatric ureteropelvic junction obstruction: a report of 85 cases].

OBJECTIVE: To investigate the clinical application of retroperitoneoscopic dismembered pyeloplasty for pediatric ureteropelvic junction obstruction (UPJO). METHODS: Of the 85 pediatric patients with UPJO, 56 were boys and 29 were girls. The age of the patients ranged from 2.5 to 11 years (mean = 4.6 years).B-ultrasonography showed hydronephrosis <15 mm (mild) in 15 patients,15-30 mm (moderate) in 59, <30 mm (severe) in the other 6. Intravenous urography (IVU) showed good imaging in 55 patients within 30 min, light imaging in 27 at 30-120 min, and no imaging in 3 after 120 min. The 85 patients underwent retroperitoneoscopic dismembered pyeloplasty. Conventional antegrade or modified antegrade double-J stenting was inserted in the 85 patients intraoperatively. RESULTS: The operation was successful in all, with no conversion to open surgery during the operation. The mean operation time was 146 min (125-240 min).The mean blood loss was 68 mL (55-112 mL).The mean postoperative hospitalization was 7 d (6-8 d ).Urine leakage occurred in 1 patient and with a good drainage, urine leakage disappeared in 1 week. Follow-up ranged 3-24 months (mean = 11 months).IVU showed on UPJ stricture, and good imaging in 75 patients within 30 min, light imaging in 10 at 30-120 min. Hydronephrosis was remitted:hydronephrosis resolution in 51 patients, mild in 6 and moderate in 3. CONCLUSION: Retroperitoneoscopic dismembered pyeloplasty is a safe, effective and mini-invasive procedure for pediatric ureteropelvic junction obstruction, with a rapid postoperative recovery. It will be the ideal treatment for UPJO in pediatric patients.