Voiding cystourethrography in patients undergoing endoscopic decompression of duplex system ureteroceles: to do or not to do?

OBJECTIVE: To assess the role of voiding cystourethrography (VCUG) in patients with duplex system ureterocele (DSU) undergoing endoscopic decompression (ED). MATERIALS AND METHODS: This is a retrospective study of 75 consecutive patients with DSU undergoing ED [median (range) age, 6 (1-148) months]. Patients were divided into 3 groups, 33 with a VCUG showing vesicoureteral reflux (VUR) before ED (VUR-group), 22 with a VCUG negative for VUR (No-VUR-group), and 20 who did not undergo a VCUG (No-VCUG-group). Secondary surgery (SS) rate was compared among groups. RESULTS: Groups were comparable for baseline characteristics. SS rate was 82% (27/33) in VUR-group vs. 32% (7/22) in the No-VUR-group (p = 0.0001), and 25% (5/20) in the No-VCUG-group (p = 0.001 vs. VUR-group, and 1 vs. No-VUR-group). In the VUR-group, 9 patients underwent preemptive endoscopic treatment of VUR during ED and SS rate was 44% (4/9) vs. 96% (23/24) in the remainder, p= 0.003. In the No-VCUG-group, a VCUG was performed during follow-up in 9/15 patients and showed reflux in all, although only 2 of these developed a (single) urinary tract infections. CONCLUSIONS: SS rate was significantly higher in patients with preoperative VUR. Instead, it was not significantly different between patients without VUR and those who did not undergo a VCUG before ED, despite all the latter who underwent a VCUG during follow-up had evidence of VUR generally in the absence of symptoms. In our opinion, a VCUG could be limited to patients developing symptoms after ED. If a VCUG is performed before ED, a preemptive treatment of VUR should be taken into consideration.

Dual-Band Frequency Selective Surface with Different Polarization Selectivity for Wireless Communication Application.

This article proposes a dual-band, frequency- and polarization-selective surface. Multiple resonant modes are introduced using the U-shaped resonator with a ground via to achieve dual-band responses and polarization selectivity. Two symmetrically grounded U-shaped resonators are coupled through electrically coupled apertures in a common ground, resulting in a passband with two transmission zeros per polarization. A general design flowchart and additional examples at the S, X, and K-bands are presented as well. A prototype at X-band is analyzed, fabricated, and measured, showing the passband center frequencies of 9.68 GHz and 10.73 GHz, factional bandwidths of 3.45% and 3.48%, and insertion losses of 0.9 dB and 1.1 dB, respectively. Due to the high selectivity, small frequency ratio, low profile, and stable performance under oblique incidence, the proposed designs have application potential in wireless communication systems.

Optimal Achievable Transmission Capacity Scheme for Full-Duplex Multihop Wireless Networks.

Full-duplex (FD) communication has been attractive as the breakthrough technology for improving attainable spectral efficiency since the 5G mobile communication system. Previous research focused on self-interference cancellation and medium access control (MAC) protocol to realize the FD system in wireless networks. This paper proposes an optimal achievable transmission capacity (OATC) scheme for capacity optimization in the FD multihop wireless networks. In this paper, the proposed OATC scheme considers the temporal reuse for spectral efficiency and the spatial reuse with transmit power control scheme for interference mitigation and capacity optimization. OATC scheme controls the transmit power to mitigate interference and optimizes the transmission capacity, which leads to the optimal achievable network capacity. We conduct the performance evaluation through numerical simulations and compare it with the existing FD MAC protocols. The numerical simulations reveal that considering only the concurrent transmissions in the FD system does not guarantee optimal transmission capacity. Moreover, the hybrid mechanism, including the sequential transmissions, is also crucial because of the interference problem. Besides, numerical simulation validates that the proposed OATC scheme accomplishes the optimal achievable network capacity with lower interference power and higher achievable throughput than the existing MAC protocols.

Power Resource Optimization for Backscatter-Aided Symbiotic Full-Duplex Secondary Transmission with Hardware Impairments in a Cognitive Radio Framework.

This paper investigates the power resource optimization problem for a new cognitive radio framework with a symbiotic backscatter-aided full-duplex secondary link under imperfect interference cancellation and other hardware impairments. The problem is formulated using two approaches, namely, maximization of the sum rate and maximization of the primary link rate, subject to rate constraints on the secondary link, and the solution for each approach is derived. The problem of a half-duplex secondary link is also solved. Simulation results show that the sum rate and exploitation of the full-duplex capability of the secondary link are strongly affected by both the problem objective and hardware impairments.

Capacity Performance for Full-Duplex Multihop Wireless Networks Using Channel Interference Balancing Allocation Scheme.

Full-duplex (FD) communication has been attractive as one of the research interests related to spectrum utilization for wireless networks from the previous evolution of communication systems. Previous studies discuss the realization of the FD system by focusing on self-interference cancellation and transmit power control in low-power wireless network scenarios. Today, capacity maximization is a key challenge in FD multihop wireless networks, in which the multi-channel allocation may lead to imbalance interference power due to the different number of simultaneous transmissions and its group selection that occurred on the same sub-channels. In this paper, we focus on the capacity maximization of the FD system by considering the influence of total interference power on each sub-channel and how to balance by selecting the different number of simultaneous transmissions to form a group that leads to a minimum difference in the total interference power on those sub-channels. Therefore, a channel interference balancing allocation (CIBA) scheme for balancing the total interference power in the multi-channel multihop wireless networks is proposed and further investigated by the idea of cooperative transmission. We also adopt the concept of interference distance to overcome the interference balancing problem of the proposed CIBA scheme. Performance evaluation results reveal that the proposed CIBA scheme achieves lesser total interference power and higher achievable capacity than other fixed channel allocation schemes.

An ectopic ureter inserting into epididymis combined with ipsilateral duplex kidney in a boy diagnosed by MRI: report of a rare case.

We present the first case of a right ectopic ureter ending in epididymis combined with an ipsilateral complete duplex kidney, presenting with painless right scrotal mass and demonstrated by magnetic resonance imaging (MRI). The boy was initially diagnosed as right testicular teratoma by ultrasound, and then underwent surgical treatment. Because of recurrence of right scrotal swelling 1 year later, MR scan was performed. MR images with body coil displayed the entire ectopic ureter, and MR images with small surface coil clearly showed anatomic details of right ureteral ectopia into epididymis. Delayed-enhanced MRI showed contrast agent in the right dilated epididymis. The boy finally received the curative right upper pole nephronureterectomy.

[The tale of two stones in an obstructed partial duplex kidney: case presentation].

Duplex renal systems is a common anomalies. Incidence rate of 0.8% in healthy adult population and 2-4% in patients investigated for urinary tract symptoms. Urolithiasis management for patients with anomalies is complex and require proper imaging and planning. We have a patient with a partial duplex collecting system presented with a right renal calculus in a non-functioning lower moiety and multiple distal ureteric calculi. Preoperative planning done and surgery performed with good outcome without any early and late complications.

Laparoscopic ligation of ectopic ureter in pediatric patients: a safe surgical option for the management of urinary incontinence due to ectopic ureters.

BACKGROUND: Ureteric ectopia is a pediatric urinary incontinence cause in girls. It is traditionally managed through hemi-nephrectomy or uretero-ureterostomy, which have the potential for complications including anastomotic stricture, leak, bleeding, and de-vascularization of the functioning renal moiety. Laparoscopic ureteric clipping has been shown to be a good alternative but has not been widely adopted yet. We provide our experience with this technique. METHODS: We retrospectively reviewed the data of 6 patients who underwent laparoscopic clipping of ectopic ureter between 2014 and 2019. We collected the following information: clinical presentation, preoperative and postoperative imaging, age at presentation, age at surgery, operative time, complications, length of stay, length of follow-up, as well as continence outcomes. RESULTS: Five patients were diagnosed with a duplex system associated with an ectopic upper pole ureter. One patient was noted to have a non-functional kidney associated with an ectopic ureter. Median age at presentation was 5 years (6 weeks-9 years), while at surgery was 8 years (2-13 years). Four patients were referred for incontinence, 1 was referred for antenatal hydronephrosis, 1 presented with urosepsis. The preoperative renal pelvis anteroposterior diameter (APD) was 8.60 cm (median) (6.80-8.70 cm). At the post-operative follow-up, the APD increased to median 9.1 cm (6.80-11.50 cm). Median operative time was 91 min (42-60 min). Complications were seen in only one patient who developed an immediate postoperative urinary tract infection (UTI). Five patients were discharged home the same day of the surgery, while the patient who developed UTI went home on post-operative day 3. Median follow-up was 33 months (22-72 months). Currently, all patients have achieved daytime urinary continence. No patient had UTI during the follow-up period. CONCLUSION: Laparoscopic ureteric clipping of the ectopic ureter appears to be a valid alternative to extirpative or reconstructive procedures. Follow-up shows an increase in hydronephrosis without any consequence for the patients. Further studies are necessary to reinforce these observations.

Transurethral incision as initial option in treatment guidelines for ectopic ureteroceles associated with duplex systems.

PURPOSE: Treatment strategies for children with ectopic ureteroceles (EUs) and duplex collecting systems or vesicoureteral reflux are controversial. Transurethral incision (TUI) of EUs associated with duplex systems has been considered only as a temporizing technique. This study aimed to evaluate whether primary TUIs could be considered as an initial treatment option in EUs with duplex systems. MATERIALS AND METHODS: Forty-seven children with EUs associated with duplex systems underwent primary TUIs at our institution between November 2007 and October 2017. We retrospectively analyzed patient characteristics such as age, sex, upper tract status, ureterocele location, differential renal function, and preoperative vesicoureteral reflux with regard to postoperative complications requiring additional surgery, postoperative incontinence, and renal function. RESULTS: The mean age at operation was 4.8 ± 4.7 months. Of the 47 patients, 26 (55.3%) underwent primary TUIs only, 3 (6.4%) underwent secondary TUIs, and 18 (38.3%) underwent other secondary procedures such as common-sheath reimplantation (CSR) and ureterocelectomy. Secondary surgeries in 21/47 (44.7%) patients occurred during a mean follow-up of 47.7 ± 23.3 months, and the most common type of secondary surgery was CSR. The most common reason for secondary surgery was febrile urinary tract infection (14/21 patients [66.7%]). There were three cases (3/26 [11.5%]) of voiding problems after primary TUI and two cases (2/15 [13.4%]) after secondary CSR. CONCLUSIONS: Primary TUIs should be considered as initial treatment options for EUs in duplex systems and not just a temporizing technique.

Robot-assisted pyeloplasty for pelvi-ureteric junction obstruction of lower moiety in partial duplex system: A technical challenge.

Management of pelvi-ureteric junction obstruction (PUJO) in a duplex system is technically challenging as dissection at the pelvis may jeopardize the vascularity of the normal moiety ureter. Anastomosing the pelvis to the one single ureter will have a risk of future development of stricture which then will risk both the moieties. Robotic assistance enables appropriate tissue dissection; minimal handling of normal ureter and precision in suturing, overcoming the potential challenges involved in the minimally invasive management of such complex cases. We report the feasibility and efficacy of robot-assisted laparoscopic pyeloplasty in such case.

Embryology, Treatment, and Outcomes of Ureteroceles in Children.

A ureterocele is a congenital cystic dilatation of the intravesical ureter that may affect either a single system kidney or the upper pole of a duplex system. The position of ureteral orifice correlates with function of associated renal moiety. Ureteroceles associated with good renal function and prompt drainage or ureteroceles associated with no renal function can be managed nonoperatively. Endoscopic puncture of ureteroceles addresses most cases; iatrogenic reflux may rarely require secondary surgery. Robot-assisted laparoscopic upper pole nephroureterectomy and ureteroureterostomy procedures are rarely associated with complications.

Prolapsed ureterocele mimicking a vulval mass in young female with complete duplex system and ureteral stone: A case report.

INTRODUCTION AND IMPORTANCE: Ureterocele is a congenital malformation of the ureter with dilatation in the distal part of the ureter. In most cases, this condition was present in childhood. In cases involving adults, this condition is associated with prolapse as well as the formation of stones. Prolapsed ureterocele with stone is considered to be a very rare case. We report a complex case of prolapsed ureterocele in a young female with a protruding mass in the vagina with complete pyeloureteral duplication and stone in the left ureterovesical junction. CASE PRESENTATION: A 19-year-old female presented to the hospital with a complaint of protruding mass in the vagina. A Computed Tomography (CT) scan and Intravenous Urography (IVU) confirmed the presence of a left ureterocele with a complete duplex system and stone in the ureterovesical junction. An endoscopic resection of the ureterocele was performed. One year following surgery, the patient was asymptomatic without deterioration of renal function or urinary tract infection. DISCUSSION: Prolapsed ureterocele in adulthood mimicking the clinical appearance of vulvar mass is considered a very rare case. The imaging examination in this case can be identified through CT-Scan. Surgical treatment of ureterocele consisted of incision, multiple punctures, unroofing, or resection. Considering the complex presentation in this case, we decided to undergo endoscopic resection to prevent the incidence of re-prolapsed which later required a second procedure. CONCLUSION: In cases of prolapsed ureterocele associated with urethral stones, endoscopic treatment is a viable option for reducing the risk of recurrent ureterocele prolapse.

Combination of robot-assisted laparoscopic pyeloplasty for lower moiety ureteropelvic junction obstruction in a partial duplex system and percutaneous endoscopic surgery for renal calculi reusing the port for robotic pyeloplasty.

Introduction: Ureteropelvic junction obstruction is often associated with renal calculus formation. However, there is no report of using robot-assisted laparoscopic pyeloplasty combined with percutaneous endoscopic surgery for ureteropelvic junction obstruction and renal calculi in a partial duplex system. Case presentation: A 19-year-old female patient with lower moiety ureteropelvic junction obstruction and renal calculi in a partial duplex system was referred to our hospital because of left lumbar pain, left acute pyelonephritis, and an increase in left renal calculi during follow-up at the referral hospital. To prevent the complication of percutaneous nephrolithotripsy following pyeloplasty, robot-assisted laparoscopic pyeloplasty combined with percutaneous endoscopic surgery was performed. Two years after surgery, the patient reported no left lumbar pain. Conclusion: The combination of robot-assisted laparoscopic pyeloplasty and percutaneous endoscopic surgery can be proposed as a safe and less-invasive treatment option for ureteropelvic junction obstruction and renal calculi in a partial duplex system.

Lower Urinary Tract Reconstruction for Ectopic Ureterocele: What Happens in the Long-term Follow-up?

BACKGROUND: We aimed to analyze the long-term clinical and lower urinary tract function outcomes in children with duplex system ectopic ureterocele who underwent ureteroneocystostomy and ureterocelectomy. METHODS: Fifty-one patients (28 females, 23 males) who underwent a series of surgical interventions including lower urinary tract reconstruction in childhood for duplex system ectopic ureterocele in our center between 1998 and 2019, were retrospectively reviewed. The demographic and clinical data, surgical history, and the indication for ureterocelectomy were noted. Lower urinary tract dysfunction (LUTD) status was assessed through dysfunctional voiding symptom scores (DVSS) and uroflowmetry in all patients at the last follow-up. The clinical outcomes, and LUTD were evaluated. RESULTS: At the last visit at a mean follow-up of 117.18 ± 57.87 months after ureterocelectomy, ipsilateral persistent lower pole VUR was detected in 5.6% (3/54 renal units, 2 females and 1 male) of the cases, who were treated using the subureteric injection. Abnormal DVSS (median 11, range 9-15) was detected in 27.4% (14/51 pts) of the patients. Out of these, 57.1% (8/14 pts) had storage symptoms, 35.7% (5/14 pts) had voiding symptoms, and 7.1% (1/14 pts) had both storage and voiding symptoms while 71.4%(10/14 pts) had abnormal uroflowmetry findings (plateau shaped flow curve in 2, staccato shaped curve with sustained EMG activity in 3, tower shaped curve in 2, interrupted shaped curve in 3 patients). Five patients had elevated residual volume. Anticholinergics were administered to six patients who had overactive bladder symptoms. In addition, two girls required open bladder neck reconstruction due to stress incontinence caused by bladder neck insufficiency. CONCLUSIONS: Our findings showed that clinical success was achieved using the lower urinary tract reconstruction with no need for re-operation in 90.2% of patients with duplex system ectopic ureterocele. However, LUTD was present in 27.4% of our patients in the long-term follow-up. Therefore, LUTD should be carefully assessed in the long-term follow-up of these patients.

Sheathless synchronous flexible ureterorenoscopy with holmium laser lithotripsy in complete duplex renal collecting system with stones.

Duplication of renal system is one of the commonest renal anomalies. It is infrequently associated with renal calculus, ureterocele and vesico ureteric reflux. We report a 29-year male with right complete duplex system having upper moiety multiple ureteric calculi and lower moiety inferior renal calculus. Single sitting fURS was done and calculi in both systems were tackled one at a time. Calculi were dusted with holmium laser and double J stent placed in upper moiety ureter. Calculus management in anomalous kidney is challenging. Single sitting flexible ureterorenoscopy is feasible option in duplex renal system with low burden calculi.

The fate of lower pole hydronephrosis after transurethral incision of upper pole ureteroceles in children with duplex systems.

PURPOSE: Duplex system is the most common upper urinary tract anomaly in childhood. The purpose of our study was to investigate the incidence, characteristics, and progression of lower pole hydronephrosis in children with duplex system who underwent transurethral incision (TUI) of upper pole ureterocele. MATERIALS AND METHODS: Among children who underwent transurethral incision of ureteroceles between 2006 and 2018, 69 renal units with duplex systems were included after exclusion of preoperative lower pole vesicoureteral reflux and follow up loss. We retrospectively analyzed the postoperative progression of lower pole hydronephrosis and compared patient characteristics between two groups according to the presence of lower pole hydronephrosis. RESULTS: The median age at operation and follow-up duration were 3.0 months (range 0-242 months) and 59 months, respectively. The median size of ureteroceles preoperatively was 14.5 mm. Thirty-five renal units (50.7%) demonstrated preoperative lower pole hydronephrosis of any grade (grade I in 13 [37.1%], II in 6 [17.1%], III in 10 [28.7%], and IV in 6 [17.1%]). In majority of cases, lower pole hydronephrosis drastically improved after transurethral incision, and 28 renal units (80%) demonstrated improvement of lower pole hydronephrosis to grade 0 or I. The preoperative diameter of upper pole ureter was significantly increased with lower pole hydronephrosis than without (11.30 ± 4.19 vs. 7.02 ± 4.94 mm, p < 0.01). Postoperative vesicoureteral reflux on upper pole was found in 16 (23%), five (7%) in lower pole. Eleven patients developed complications after TUI which required secondary surgeries. The differential renal function of affected renal units was decreased after TUI in group with preoperative lower pole hydronephrosis (46.77 ± 8.21 to 44.24 ± 8.55, p = 0.003), while it was maintained without significant difference in group without lower pole hydronephrosis (47.90 ± 6.39 to 46.24 ± 8.90, p = 0.091). CONCLUSIONS: Lower pole hydronephrosis was found in a considerable number of renal units (50.7%), and the occurrence was related with the diameter of upper pole ureter. Most of renal units demonstrated significant improvement of lower pole hydronephrosis after transurethral incision of ureterocele. Given that differential renal function may be decreased even after improvement of hydronephrosis with TUI, a more careful monitoring on renal function is required in patients with hydronephrosis on lower pole.

Robot-assisted laparoscopic pyeloplasty for ureteropelvic junction obstruction with duplex system.

Management of ureteropelvic junction obstruction with a duplex system is technically challenging even when laparoscopic procedure is the standard approach for ureteropelvic junction obstruction. The patient was an otherwise healthy 21-year-old woman who presented with symptomatic ureteropelvic junction obstruction with the duplex system, which was completely excised using a robot-assisted approach. Robotic assistance allows for proper tissue dissection, minimal manipulation of the normal ureter, and meticulous fine suturing and would overcome the potential challenges involved in the minimally invasive management of such complex anomalies as shown in this patient.

Cystoscopic transurethral incision in simplex and duplex ureteroceles-is it the definitive procedure?

OBJECTIVE: The aim of this study is to evaluate the efficacy of primary cystoscopic transurethral incision (CTUI) in the management of paediatric ureteroceles. The secondary aim is to compare the efficacy of CTUI between simplex and duplex systems. PATIENTS AND METHODS: This is a retrospective review of consecutive paediatric patients requiring surgical intervention for ureterocele. Data collected for analysis included demographics, diagnostic, pre-operative investigations, operative interventions and postoperative variables. RESULTS: Over a 19-year period, 79 consecutive cases were identified, and 42 were male (53.2%). The mean follow-up was 6.7 years. Seventy-three (92.4%) cases underwent primary CTUI; 50 of these cases (68.5%) required no further procedures during the study period. Sixty-one cases were treated by endoscopic intervention alone (77.2%). Forty-one (51.9%) cases had a simplex system, and 38 (48.1%), a duplex system. There was no statistically significant difference in the efficacy of primary CTUI in simplex vs duplex systems. Of the 20 patients who had pre-operative and postoperative micturating cystourethrograms performed, seven (35%) developed de-novo postoperative vesicoureteric reflux after CTUI. CONCLUSION: Primary CTUI is a safe, minimally invasive procedure that is definitive in the majority of children presenting with a ureterocele that requires intervention. There was no difference in success of primary CTUI between simplex or duplex systems.

Double collecting system with ectopic ureterocele masquerading as an ovarian torsion.

OBJECTIVE: Ureterocele in a duplex system is rare and commonly presented with urinary tract infection at neonatal age, infant or childhood. Symptomatic ureterocele in reproductive-age is a diagnostic challenge and should be highly awarded to avoid miss-diagnosis. CASE REPORT: An adolescent girl with right ectopic ureterocele presented as acute abdomen that mimicked ovarian torsion received emergent laparoscopic surgery. Right ureterocele was identified and excised. Computed tomography later showed bilateral renal duplications with visible renal parenchyma and upper ureters. Recurrent abdominal pain with pelvic abscess occurred 10 days after surgery. Laparoscopic right partial nephrectomy of the upper moiety and resection of the residual ureterocele was performed. Cystoscopy showed absence of intravesical ureterocele and her symptoms were completely resolved after surgery. CONCLUSION: Infected ureterocele in a duplex system is a rare condition and should be kept in mind as differential diagnosis.

Duplex System with Ectopic Ureter Opens into the Posterior Urethra: Case Report.

INTRODUCTION: Duplicated ureter or Duplex Collecting System is a congenital condition in which the ureteric bud, the embryological origin of the ureter, arises twice, resulting in two ureters draining a single kidney. This congenital anomaly is rare, and even rarer when the duplex system with ectopic ureter is present. This type of congenital anomaly is even more rarely diagnosed and surgically treated in adulthood. CASE REPORT: This case report presents a case of a 32-year-old male, who had a duplex collecting system with two ureters on the left side. Ectopic ureter, draining the upper pole of the left kidney, opened into the posterior urethra. In our patient, taking into account the clinical perspective, the renal tissue damaging of the upper pole which was not functional, partial nephrectomy and ureterectomy was successfully performed.