Feasibility of multi-section continuum robotic ureteroscope in the kidney.

Our objective was to evaluate the feasibility of a multi-section continuum robotic ureteroscope to address the difficulties with access into certain renal calyces during flexible ureteroscopy. First, the robotic ureteroscope developed in previous research, which utilizes three actuated bendable sections controlled by wires, was modified for use in this project. Second, using phantom models created from five randomly selected computer tomography urograms, the flexible ureteroscope and robotic ureteroscope were evaluated, focusing on several factors: time taken to access each renal calyx, time taken to aim at three targets on each renal calyx, the force generated in the renal pelvic wall associated with ureteroscope manipulation, and the distance and standard deviation between the ureteroscope and the target. As a result, the robotic ureteroscope utilized significantly less force during lower pole calyx access (flexible ureteroscope vs. robotic ureteroscope; 2.0 vs. 0.98 N, p = 0.03). When aiming at targets, the standard deviation of proper target access was smaller for each renal calyx (upper pole: 0.49 vs. 0.11 mm, middle: 0.84 vs. 0.12 mm, lower pole: 3.4 vs. 0.19 mm) in the robotic ureteroscope group, and the distance between the center point of the ureteroscope image and the target was significantly smaller in the robotic ureteroscope group (upper: 0.49 vs. 0.19 mm, p < 0.001, middle: 0.77 vs. 0.17 mm, p < 0.001, lower: 0.77 vs. 0.22 mm, p < 0.001). In conclusion, our robotic ureteroscope demonstrated improved maneuverability and facilitated accuracy and precision while reducing the force on the renal pelvic wall during access into each renal calyx.

Calyceal diverticula: Clinical, radiological and histopathological findings of an uncommon entity with presumed congenital origin.

Calyceal diverticula (CD) are relatively uncommon urologic conditions that generally follow an asymptomatic course and rarely require medical intervention. CD are thought to have a congenital origin due to abnormalities during the process of ureteral bud formation. Clinically and radiologically, they can mimic multiple neoplastic and non-neoplastic renal processes, with potentially relevant differences in the management of these patients. Symptoms are usually associated with the presence of stones, obstruction to the drainage of the diverticulum, large size, or secondary infection. In chronic cases, surgery might become necessary, creating an opportunity to examine the histopathological characteristics of this condition. Although these are benign in the majority of patients, some rare instances of malignancy arising from the CD have been reported. In this series, we addressed the clinical, radiological, and histopathological findings of CD.

A case report of renal calyceal diverticulum with hypertension in children and review of literature.

BACKGROUND: Renal calyx diverticulum refers to a cystic lesion covered with the transitional epithelium in the renal parenchyma. Although there is no clear evidence that calyx diverticulum can cause hypertension, there exists a close association between the two, and there are few related reports. Herein, we reported the case of a child with renal calyx diverticulum complicated with hypertension and summarized the diagnosis and treatment. CASE PRESENTATION: Physical examination of the patient, an 11-year-old child, revealed a left renal cyst with hypertension (155/116 mmHg). There were no related symptoms. Routine urine and blood biochemical examinations showed no abnormalities. Imaging revealed left renal cyst compression causing the hypertension. She underwent renal cyst fluid aspiration and injection of a sclerosing agent into the capsule, but her blood pressure increased again 3 days postoperatively. Color Doppler ultrasonography showed that the size of the left renal cyst was the same as that preoperatively. To further confirm the diagnosis, cystoscopic retrograde ureteropyelography was performed to confirm the diagnosis of renal calyx diverticulum. Subsequently, renal calyceal diverticulum resection and calyx neck enlargement were performed. The operation went smoothly and the blood pressure returned to normal postoperatively. No abnormalities were noted at the 7-month postoperative follow-up. CONCLUSION: There exists an association between renal calyx diverticulum and hypertension. Therefore, hypertension can be considered a surgical indication for renal calyx diverticulum. Moreover, renal calyceal diverticulum in children can be easily misdiagnosed as a renal cyst. Therefore, it is important to be vigilant to prevent a series of complications, such as postoperative urine leakage, in such cases.

Calyceal Diverticula Disease: Diagnosis and Management Options in the Era of Non-Contrast CT Scan.

INTRODUCTION: Calyceal diverticula (CD) are traditionally diagnosed by contrast studies. However, non-contrast CT is the standard imaging modality for kidney stones. Therefore, we aimed to determine if the lack of contrast imaging affected outcomes of the management of symptomatic CD with stone. MATERIALS AND METHODS: This is a retrospective study of patients diagnosed with CD with intracalyceal stone from 2000 to 2017 analyzing demographics, clinical data, and success of different treatment options. The timing of CD diagnosis is correlated to the success of the first treatment. RESULTS: Forty-eight patients were found. CD was diagnosed prior to intervention in 20 (42%) cases and intraoperatively during flexible ureteroscopy in 17 (35%) and 11 (23%) cases were diagnosed after failed intervention, mainly ESWL. We found that the success rate of treatment was highly affected by the timing and modality of diagnosis. Preoperative diagnosis of CD was associated with 69% success rate of the first intervention. In contrast, there was a 0% success rate of first treatment if CD was not diagnosed with contrast imaging. Furthermore, univariate analysis showed no significant association between sociodemographics and clinical variables and success treatment (p > 0.05). CONCLUSIONS: The delay in diagnosing CD with stone contributes significantly to the success rate and the number of treatments.

Air vs contrast pyelogram for initial puncture access in percutaneous nephrolithotomy: a randomized controlled trial.

Percutaneous nephrolithotomy (PCNL) is a standard procedure for large renal stones. Contrast (traditionally) as well as air is being used to delineate pelvi-calyceal system (PCS) to perform initial puncture. Contrast, when used has certain disadvantages including poor differentiation of anterior and posterior calyces. In this interim analysis of 122 patients of a prospective study subjects were stratified in two groups: in group 1, contrast was used while in group 2, air was used to delineate PCS. Out of 122,103 patients underwent puncture by contrast or air exclusively while 19 patients required mix of contrast and air (14 patients failed puncture using contrast while 5 using air). Mean dosage of radiation exposure (8.43 vs. 14.26 mGy), duration of radiation exposure (0.66 vs. 1.02 min), access time (3.72 vs. 5.84 min), were less in group 2 as compared to group 1. 84.5% of patients underwent puncture in single attempt in group 2 as compared to 56.25% in group 1. Five patients had post-operative fever and one had trans-pleural tract dilation. Complete stone clearance was seen in 94.8% of patients using air to only 75% of patients using contrast. Conclusion: Air pyelogram is a feasible, safe, cost effective and efficient access alternative to contrast pyelogram and in difficult situation a mixture of both is better than using one.

[A Case of Calyceal Diverticula with Stones Treated by Ureteroscopic Management].

Most patients with calyceal diverticula stones are asymptomatic, but some patients experience fever and low back pain. Here we report a case of calyceal diverticula stones treated by ureteroscopic management. A 41-year-old woman with backache visited a local doctor. She was diagnosed with a urinary tract infection, and prescribed an antibiotic. Her symptoms began to improve, but the ultrasonography showed she had a left renal cystic lesion, so she visited our hospital. Abdominal contrast-enhanced computed tomography (CT) showing in-flow of a contrast agent into the left renal calyceal diverticula located stones in the upper pole. We performed ureteroscopic management of the calyceal diverticula stones in two stages. First, we expanded the neck of the calyceal diverticula by indwelling the ureteral stent at the calyceal diverticula. Then, using a ureteral dilator, we expanded the neck of the calyceal diverticula further and removed the stones in the calyceal diverticula. Treatment with ureteroscopic management was possible due to the location of the calyceal diverticula stones and the success rate was increased by performing the treatment in two stages.

Robot-assisted laparoscopic unroofing and fulguration of sequestered caliceal diverticula cluster.

INTRODUCTION: We report a rare case of four sequestered caliceal diverticula that failed previous percutaneous sclerotherapy and were subsequently managed with robot-assisted laparoscopic unroofing and fulguration of the sequestered diverticula cluster. METHODS: A 6 year-old female was admitted for urosepsis and flank pain. At age 2, a previous institution diagnosed a caliceal diverticulum. Prolonged-delayed magnetic resonance urography confirmed four sequestered caliceal diverticula. Intraoperative ultrasonography identified the diverticula cluster and ensured decompression. The defects were closed after ablating the blood supply, unroofing and decompressing the diverticula, and fulgurating the caliceal lining. RESULTS: Console time was 4 h with an estimated blood loss of 30-50 cc. The patient was discharged post-op day 3. Follow-up renal ultrasound at 6 weeks and 5 months demonstrated progressive atrophy of the left upper pole with preservation of the lower pole size and perfusion. At 9 months, the patient is free of symptoms and urinary tract infections. CONCLUSION: Closure of unroofed and fulgurated diverticula may be considered when diverticula are anatomically sequestered from the renal collecting system. Robotic-assisted laparoscopic unroofing and fulguration is a technically feasible approach for treatment of sequestered caliceal diverticula in pediatric patients. Additional studies and monitoring of long-term renal function are required.

Patient Counseling Through the Pelvicalyceal-shaped Labyrinth: In Search of an Easy Understanding of the Upcoming Stone Removal: A Pilot Study.

OBJECTIVE: To investigate the impact of a mobile application (app) displaying a visualization of the internal anatomy of the pelvicalyceal systemPCS and of kidney stones on patient understanding of their affected kidney anatomy and their upcoming percutaneous nephrolithotripsy (PCNL). MATERIALS AND METHODS: One-hundred patients who required PCNL were included in this study, and all patients were nonrandomly distributed into 2 groups: counseled using only 3D-reconstructed computed tomography (CT) images (group 1) or using only the "InsKid" app (group 2). Patient data were obtained from CT scans as Digital Imaging and Communications in Medicine format and converted into stereolithography (STL) format. All patients completed the questionnaire after counseling, and the results were compared between groups. RESULTS: Patients from group 2 better understood the anatomy of their affected kidney by 53%; awareness regarding their stone location was better by 32%; the steps of planned surgery, as well as possible complications, were more transparent for patients using the app by 24% and 56%, respectively. The number of patients who were dissatisfied with the mobile counseling dropped by 70%. The average duration of consultation with the 3D reconstruction of CT images was 10.9 ± 0.6 min, while counseling using our program reliably led to a reduction in this duration (7.3 ± 0.5 min). CONCLUSION: The InsKid app is a freely available, easy-to-use educational software that improves patient counseling without considerable financial expense or long waiting periods for use.

The left ureterocele and stone of calyceal diverticulum in the patient with bilateral incomplete duplex kidneys managed by flexible ureteroscopy: a case report and literature review.

BACKGROUND: Duplex kidneys are one of the most common renal congenital abnormalities, mostly asymptomatic and of no clinical significance. There are little reports about the left ureterocele and stone of calyceal diverticulum in patients with bilateral incomplete duplex kidneys managed by flexible ureteroscopy. CASE PRESENTATION: A 69-year-old Chinese woman was presented with left waist pain for 1 month. A preoperative computed tomography (CT) scan and intravenous pyelogram revealed the left ureterocele which located in the left ureterovesical junction, and stone of calyceal diverticulum which located in the upper kidney of left incomplete duplex kidneys. The ureterocele was confirmed in view of ureteroscopy and the holmium laser was used for the resection of ureterocele. It took us a lot of efforts to find out the stone because of diverticular neck stenosis. Fortunately, when diverticular neck stenosis was incised internally by holmium laser, the stone was discovered clearly and removed using the holmium laser and nitinol stone basket through flexible ureteroscopy. A double-J ureteral stent was inserted and remained in place for 1 month. The symptom disappeared postoperatively and no complications were developed during the placement of the stent. There were no stone residents observed on CT scan before removing the ureteral stent 1 month later. CONCLUSIONS: Flexible ureteroscopy with holmium laser is feasible to manage the ureterocele and calyceal diverticulum stones in patients with bilateral incomplete duplex kidneys in one operation.

Comparative Study of Percutaneous Tic Technique Vs Standard Percutaneous Nephrolithotomy.

OBJECTIVE: To compare the PERC-tic technique, described as placement of dual wires under fluoroscopic guidance adjacent to the stone within the obstructed calyx, to standard percutaneous nephrolithotomy (PCNL) with working wires secured down the ureter. MATERIALS AND METHODS: This is a retrospective cohort study of patients who underwent a PCNL procedure between October 2016 and November 2018. Patients undergoing the PERC-tic technique were compared to patients undergoing standard PCNL. Regression models evaluated if PERC-tic PCNL was associated with equivalent stone-free rates to standard PCNL at 90 days, need for secondary procedures, and 90-day hospital readmission. RESULTS: This study involved 126 PCNL cases of which 63 were done using the PERC-tic technique and 63 with standard PCNL. In multivariate analysis, there was no statistical difference in 90-day stone-free rate between standard PCNL and PERC-tic cohorts (P = .08). We did note a 6 times higher likelihood of needing secondary procedures for residual stones in the PERC-tic vs standard PCNL groups (71% vs 30% P <.0001). There was no statistical significance in 90-day hospital readmission rates between groups (P = .47). CONCLUSION: Our findings suggest similar stone-free rate at 90 days and higher rates of secondary procedures after PERC-tic PCNL compared to the standard approach; however, there was no difference in complications. These findings may reflect decreased visualization with the PERC-tic technique or simply be reflective of the case difficulty requiring the use of the PERC-tic technique. These findings can be used for patient counseling when considering this technique for complex stone disease.

Challenges in the diagnosis of calyceal diverticulum: A report of two cases and review of the literature.

BACKGROUND: Calyceal diverticula outpouchings that occur rarely in the upper collecting system of the kidney and is often difficult to detect. In this study, we present two cases of calyceal diverticula and discuss their clinical characteristics and radiologic features. PATIENTS AND METHODS: In the presented two cases, we applied several imaging examinations, including delayed intravenous pyelography, retrograde pyelography and axial computerized tomographic (CT) scanning of the kidneys with and without contrast. Serum creatinine levels in fluid withdrawn from the diverticula were found to be significantly higher than the simultaneous serum creatinine levels. Intravenous injection of methylene blue through a ureteral catheter was also aided in the diagnosis. Calyceal diverticulum neck dilatation was performed through a percutaneous nephroscope.ResultsThe two cases were diagnosed preoperatively and the operation was successful performed. The nephrostomy tube was removed seven days after surgery without complications. CT scans of the kidney after six months showed that the size of the calyceal diverticulum of two patients were considerably smaller than pre-surgery. There were no reports of pain in the lumbar region or other discomfort. COMMENTS: Diagnosis of calyceal diverticulum mainly depend on a variety of imaging examinations, including the delayed intravenous pyelography, retrograde pyelography, and kidney CT plain scan plus enhanced scan. If the patient cannot be diagnosed by above methods, cyst fluid can be aspirated percutaneously to measure the preoperative creatinine level. If it is significantly higher than the serum creatinine level, the cyst fluid is considered urine, which can assist in the diagnosis of calyceal diverticulum. A ureteral catheter should also be inserted before operation namely, intravenous injection of methylene blue through a ureteral catheter is helpful for diagnosis. The choice of surgical treatment is based on the size and location of calyceal diverticulum and clinical manifestations.

Laser Endoscopic X-Ray-Guided Intrarenal Tract: Comparison Among Renal Access Modalities in the Porcine Kidney.

Introduction and Objectives: Laser endoscopic X-ray-guided intrarenal tract (LEXIT) is a recently described holmium laser retrograde access technique for creating percutaneous access during a percutaneous nephrolithotomy. We compared bleeding, ease of access, and the time to achieve access for each of the following three modalities: LEXIT, retrograde Lawson puncture wire, and antegrade 18-gauge nephrostomy needle access in the porcine kidney. Methods: Eight pigs underwent an average of five nephrostomy accesses per kidney under simultaneous laparoscopic vision at 5 mm Hg insufflation pressure. Data collected included: access time (seconds), bleeding intensity (scale: 1 [no bleeding] - 10 [severe bleeding]), bleeding duration (seconds), accuracy of caliceal entry, and surgeon comfort with the technique (scale: 1 [very easy] - 10 [very difficult]). Results: A total of 64 nephrostomy accesses were obtained. The speed of nephrostomy access with LEXIT was significantly faster than the nephrostomy needle and Lawson wire (p < 0.001). Bleeding intensity (p = 0.002) and severity (p = 0.001) were lower with the Lawson puncture wire, followed by LEXIT and then by the nephrostomy needle. LEXIT was rated as easier in acquiring access within the upper pole (p = 0.003) and interpolar calices (p < 0.001). Histopathology demonstrated no difference in parenchymal damage between LEXIT and nephrostomy needle (p = 0.18); however, LEXIT was associated with significantly increased peri-tract thermal injury, although within a narrow focus of 1.6 mm (p < 0.01). Conclusion: Among the three renal access techniques, LEXIT provided the fastest access times and greatest ease of access specifically for upper pole and interpolar calices. Also, bleeding with LEXIT was significantly less compared with the standard antegrade nephrostomy needle access. Histopathological analysis demonstrated that the holmium laser resulted in focal thermal tissue effects similar in range to the blunt tissue trauma caused by the 18-gauge nephrostomy needle.

Divertículo calicial y su diagnóstico incidental / Calyceal diverticulum and its incidental diagnosis

Introducción: El divérticulo calicial se detecta en 0,21 a 0.60 por ciento de los urogramas excretores. Objetivos: Describir una paciente con diagnóstico incidental de esta anomalía y su seguimiento durante 11 años. Presentación del caso: Durante la realización de un urograma excretor para el estudio de una hidronefrosis en una niña de siete años de edad, se detectó un divertículo calicial en el riñón contralateral y después de 11 años de seguimiento ultrasonográfico no se ha demostrado modificación ni complicación del divertículo. Conclusiones: El divertículo calicial es una anomalía congénita que puede mantenerse sin complicaciones durante años por lo que debe tratarse conservadoramente(AU)

ABSTRACT Introduction: Calyceal diverticulum is detected in 0,21 percent to 0.60 percent of excretory urogram. Objectives: To describe a patient with an incidental diagnosis of this anomaly and her follow up during 11 years. Case presentation: During the performance of an excretory urogram for studying a hydronefrosis in a seven years old girl, a calyceal diverticulum was detected in the contralateral kidney; and after 11 years of ultrasonographic follow-up there has been no modifications or complication related with the diverticulum. Conclusions: Calycial diverticulum is a congenital anomaly that can last years without presenting complications. That is why it must be treated conservatively(AU)

Assessment of Residual Stone Fragments After Retrograde Intrarenal Surgery.

OBJECTIVES: To define the most suitable approach to assess residual stone fragments after retrograde intrarenal surgery (RIRS). METHODS: Ninety-two patients (115 renal units) submitted to RIRS for symptomatic kidney stones >5 mm and <20 mm or <15 mm in the lower Calyx diagnosed by noncontrast CT (NCCT) were prospectively studied. Residual fragments were assessed by endoscopic evaluation (END) at the end of the procedure and by NCCT, ultrasonography (US), and kidney, ureter, and bladder radiograph (KUB) on the 90th postoperative day (POD). NCCT was considered the gold standard for the evaluation of residual fragments after RIRS. RESULTS: The 90th POD NCCT resulted in stone-free status in 74.8% (86/115), 0-2 mm in 8.7% (10/115), and >2 mm residual fragments in 16.5% (19/115) renal units. Stone-free status by END at the end of RIRS was coincident with NCCT in 93.0% of the cases (40/43). There were no cases of residual fragments >2 mm on NCCT if END resulted in stone-free status. In all cases where END resulted in residual fragments >2 mm, US proved to be correct according to NCCT. Neither US nor KUB was able to identify residual fragments between 0 and 2 mm. KUB had only 31.6% (6/19) sensitivity to detect residual fragments >2 mm and did not add sensitivity or specificity to US. CONCLUSIONS: In the follow-up imaging after RIRS, we suggest that if END resulted in residual fragments <2 mm, a 90th POD NCCT should be performed. US may be used if END showed fragments >2 mm.

Ileocalicostomy Ureteral Substitution for Complex Ureteropelvic Junction Stricture: Technique and Initial Experience.

OBJECTIVE: To present our novel surgical technique, ileocalicostomy ureteral substitution, for the management of long upper ureteral strictures in patients without a dilated extra-renal pelvis. MATERIALS AND METHODS: Two patients were identified with long, complex proximal ureteral strictures who were treated with our novel surgical technique by a single surgeon at a single institution. Perioperative data for these two patients are presented along with a detailed description of the surgical technique. RESULTS: Ileocalicostomy ureteral substitution was successfully performed in two cases. The total operative time for these cases was 436 minutes and 246 minutes, with estimated blood loss of 300 mL and 200 mL. Length of stay for the two patients was 8 days and 6 days, respectively. There were no major (Clavien-Dindo Classification ≥ grade 3) complications. Both patients are entirely free of urinary tubes with unobstructed kidneys since reconstruction. CONCLUSION: Ileocalicostomy ureteral substitution is a feasible reconstructive option for select patients. To our knowledge this report is the initial experience in the literature presented.

Calyceal diverticula in children: imaging findings and presentations. / Divertículos caliciales en niños: hallazgos radiológicos y formas de presentación.

A calyceal diverticulum consists of a cystic eventration in the renal parenchyma that is lined with transitional cell epithelium with a narrow infundibular connection with the calyces or pelvis of the renal collector system; thus, the term pyelocalyceal diverticulum would be more accurate. Very rare in pediatric patients, calyceal diverticula can be symptomatic and require treatment. Calyceal diverticula are underdiagnosed because they can be mistaken for simple renal cysts on ultrasonography. To determine the approach to their follow-up and management, the diagnosis must be confirmed by excretory-phase computed tomography (CT) or magnetic resonance imaging (MRI). This article aims to show the different ways that calyceal diverticula can present in pediatric patients; it emphasizes the ultrasonographic findings that enable the lesion to be suspected and the definitive findings that confirm the diagnosis on CT and MRI. It also discusses the differential diagnosis with other cystic kidney lesions and their treatment.

[Congenital megacalycosis in a girl with unilateral renal agenesis]. / Wrodzone kielichonercze u dziewczynki z jednostronna agenezja nerki.

Renal agenesis occurs in pediatric population with the incidence 1:500- 2000 children. It is more often diagnosed in boys and on the left side of the body. Renal agenesis may be isolated or it may be a part of complex malformation syndrome. Megacalycosis is a very rare anomaly of urinary tract associated with abnormal structure of the kidney pyramids. AIM: The aim of the study was to present for the first time in the medical literature the case of a girl with unilateral renal agenesis and megacalycosis. CASE REPORT: A girl, born at term in good general medical condition, and with normal birth weight was admitted to the hospital because of urinary tract infection caused by E.coli. Antenatal abdominal ultrasounds were normal. In a diagnostic, repeated ultrasound studies, unilateral, left renal agenesis and the righ-sided megacalycosis were found. The right kidney had dilated collecting system, with normal size of renal pelvis and enlarged calyces up to 26 mm. The kidney function was normal. Voiding cystourethrography excluded vesicoureteral reflux. Dynamic scintigraphy 99mTc-EC showed the lack of function of the left kidney, postinflammatory changes and dilation of collecting system without signs of obstruction. During two-years follow up we didn't observe clinical relapse of urinary tract infection. Blood pressure and kidney function were normal. CONCLUSIONS: Complex congenital anomalies of the kidney and the urinary tract (CAKUT) can be diagnosed at any age. Normal antenatal abdominal ultrasound does not exclude CAKUT. Every patient with congenital abnormalities of the kidney and the urinary tract requires long-term follow up, because of increased risk of chronic kidney disease.

Prediction of Intraoperative Urinary Collecting System Entry in Patients with Peripheral Renal Tumors Undergoing Partial Nephrectomy: Usefulness of Tumor-Centered Multiplanar Reconstruction.

OBJECTIVE: To assess the usefulness of tumor-centered multiplanar reconstruction (TC-MPR) for predicting intraoperative urinary collecting system (UCS) entry in patients with peripheral renal tumors undergoing partial nephrectomy (PN). METHODS: Dynamic computed tomography images of 50 peripheral cT1 renal tumors treated with laparoendoscopic PN were analyzed. TC-MPR generated a digital cross-sectional image showing the tumor center and the closest calyx on a same plane. Patients and tumor characteristics including the distance from the tumor margin to the closest calyx (MPR-distance), and the angle formed by 2 tangent lines from the closest calyx to the tumor (MPR-angle) were assessed. RESULTS: Intraoperative UCS entry was observed in 15 patients (30%). The patients who experienced intraoperative UCS entry had a higher RENAL score, wider MPR-angle, and shorter MPR-distance than those who did not (p = 0.04, p = 0.001, p < 0.001, respectively). Multivariate analysis identified MPR-angle as an independent factor for intraoperative UCS entry (p < 0.001). CONCLUSIONS: The spatial information assessed using TC-MPR serves as a predictive factor for intraoperative UCS entry during PN.