SabreSource™: a novel percutaneous nephrolithotomy apparatus to aid collecting system puncture - a preliminary report.

BACKGROUND: Successful percutaneous nephrolithotomy (PCNL) relies on a technically challenging, precise needle puncture of the renal collecting system. We aimed to compare, in an ex vivo model, the use of a real time image guidance system (the SabreSource™) and a mechanical stabilising device with conventional manual techniques for the accuracy of needle placement. METHODS: The SabreSource™ system (Minrad International Inc.; New York, USA) is a real time image guidance system. The system platform is mounted on a C-arm fluoroscope. It employs targeting cross hairs on the fluoroscopic image that can be easily positioned to target the desired renal calyx. The system directs a visible laser beam onto the patient which is precisely aligned with the cross hairs on the fluoroscopic image. This provides the correct "bull's-eye" angle of approach to the calyx, even after the x-ray source is turned off. The locator then stabilises the needle in the "bull's-eye" position so that only screening for depth is required. Objective assessment using a simulated PCNL puncture was performed by 7 urologic trainees on a kidney phantom with and without using the SabreSource™. Fluoroscopy screening time (FST) and amount of radiation (mGy) used to achieve successful puncture were compared. RESULTS: Simulated PCNL puncture was quicker and resulted in reduced radiation exposure when the apparatus was used. The mean FST for traditional "bull's-eye" vs SabreSource™ puncture was 17 vs 5 seconds (p = 0.01), and the mean radiation exposure to puncture was 0.7 vs 0.2 mGy (p = 0.03), respectively. CONCLUSION: The SabreSource™ is a novel assistant to achieving successful PCNL puncture. In combination with "the locator" the preliminary in vitro testing suggests that the device reduces fluoroscopy exposure and is quicker. The device warrants further evaluation in the clinical setting.

Robot-assisted laparoscopic lower pole partial nephrectomy in the pediatric patient.

INTRODUCTION: In pediatric urology, partial nephrectomy is used primarily to remove a non-functioning renal moiety in a duplicated system. There are few data on infants undergoing this procedure. As such, we present a robot-assisted laparoscopic lower pole partial nephrectomy in an infant. METHODS: Our patient was an 11-month-old (10.7 kg) male with a history of prenatal hydronephrosis, who was diagnosed postnatally with a duplicated right collecting system and severe hydroureteronephrosis of the right lower collecting system. A DMSA scan demonstrated no radiotracer uptake in the right lower pole. A robot-assisted laparoscopic lower pole partial nephrectomy was performed. RESULTS: A lower pole partial nephrectomy was accomplished. At 1 month postoperatively, an ultrasound demonstrated no hydronephrosis or perinephric fluid collection. CONCLUSIONS: Robotic partial nephrectomy is safe and feasible in pediatrics including both older children and infants. It is successful for both upper and lower pole partial nephrectomies.

Duplicated Renal Collecting System With Ectopic Ureter in Female Bladder Exstrophy: A Case Report.

Bladder exstrophy is a rare major birth defect which requires specialized surgical care. Associated genitourinary tract anomalies are extremely rare in this population, yet significantly impact surgical planning and outcomes. In this case, a full-term newborn girl with a prenatal diagnosis of classic bladder exstrophy was found to have a complete duplicated left collecting system with an ectopic ureter inserted to urethral plate. The patient underwent modern staged repair of exstrophy with bilateral anterior innominate osteotomies and concomitant ureteral reimplantation-the first reported case of ureteral reimplantation at the time of initial closure in a newborn.

Gross haematuria associated with penetration of an inferior vena cava filter into the right renal collecting system.

Inferior vena cava (IVC) filters are a viable alternative for patients with venous thromboembolic disease for whom standard anticoagulation therapy is contraindicated. Rare complications associated with their use, however, include misplacement and IVC penetration. We report a case of a 63-year-old woman who developed gross haematuria following IVC filter penetration into both the right renal collecting system and renal pelvis, for which open caval removal and reconstruction was required. This is an unusual case of IVC filter penetration causing symptomatic haematuria and requiring surgical intervention.

Robot assisted heminephrectomy for duplicated renal collecting system: technique and outcomes.

BACKGROUND: The aim of this study was to describe experience with robotic assisted hemi-nephrectomy (RAHN) for the management of duplicated renal collecting system. METHODS: The authors' institutional database was queried to identify patients who underwent RAHN from 2007 to 2013 for the management of a duplicated system. Patient demographics, indications and surgical outcomes were reviewed and analyzed. RESULTS: Five patients were identified with a duplicated system of which all had a history of pain and recurrent infection. Three patients underwent hemi-nephrectomy for a poorly functioning lower pole and two for an abnormal upper pole moiety. All operations were completed successfully using a robotic approach. There were only two minor (Clavien grade 1-2) complications. CONCLUSIONS: RAHN is a viable option for the surgical treatment of an atrophic, chronically infected duplicated system. The unique features of robotic technology offer enhanced dexterity and vision facilitating the management of complex vascular and ureteral anatomy.

Step-by-Step robotic heminephrectomy for duplicated renal collecting system.

INTRODUCTION: A duplicated renal collecting system is a relatively common congenital anomaly rarely presenting in adults. AIM: In this video we demonstrate our step-by-step technique of Robotic heminephrectomy in a patient with non-functioning upper pole moiety. MATERIALS AND METHODS: Following cystoscopy and ureteral catheter insertion the patient was placed in 60° modified flank position with the ipsilateral arm positioned at the side of the patient. A straight-line, three arm robotic port configuration was employed. The robot was docked at a 90-degree angle, perpendicular to the patient. Following mobilization the colon and identifying both ureters of the duplicated system, the ureters were followed cephalically toward, hilar vessels where the hilar anatomy was identified. The nonfunctioning pole vasculature was ligated using hem-o-lok clips. The ureter was sharply divided and the proximal ureteral stump was passed posterior the renal hilum. Ureteral stump was used as for retraction and heminephrectomy is completed along the line demarcating the upper and lower pole moieties. Renorrhaphy was performed using 0-Vicryl suture with a CT-1 needle. The nonfunctioning pole ureter was then dissected caudally toward the bladder hiatus, ligated using clips, and transected. RESULTS: The operating time was 240 minutes and blood loss was 100 cc. There was no complication post-operatively. CONCLUSIONS: Wrist articulation and degree of freedom offered by robotic platform facilitates successful performance of minimally invasive heminephrectomy in the setting of an atrophic and symptomatic renal segment.

Step-by-Step robotic heminephrectomy for duplicated renal collecting system

Introduction A duplicated renal collecting system is a relatively common congenital anomaly rarely presenting in adults. Aim In this video we demonstrate our step-by-step technique of Robotic heminephrectomy in a patient with non-functioning upper pole moiety. Materials and Methods Following cystoscopy and ureteral catheter insertion the patient was placed in 600 modified flank position with the ipsilateral arm positioned at the side of the patient. A straight-line, three arm robotic port configuration was employed. The robot was docked at a 90-degree angle, perpendicular to the patient. Following mobilization the colon and identifying both ureters of the duplicated system, the ureters were followed cephalically toward, hilar vessels where the hilar anatomy was identified. The nonfunctioning pole vasculature was ligated using hem-o-lok clips. The ureter was sharply divided and the proximal ureteral stump was passed posterior the renal hilum. Ureteral stump was used as for retraction and heminephrectomy is completed along the line demarcating the upper and lower pole moieties. Renorrhaphy was performed using 0-Vicryl suture with a CT-1 needle. The nonfunctioning pole ureter was then dissected caudally toward the bladder hiatus, ligated using clips, and transected. Results The operating time was 240 minutes and blood loss was 100 cc. There was no complication post-operatively. Conclusions Wrist articulation and degree of freedom offered by robotic platform facilitates successful performance of minimally invasive heminephrectomy in the setting of an atrophic and symptomatic renal segment. .

Should blunt segmental vascular renal injuries be considered an American Association for the Surgery of Trauma Grade 4 renal injury?

BACKGROUND: Renal segmental vascular injury (SVI) following blunt abdominal trauma is not part of the original American Association for the Surgery of Trauma (AAST) renal injury grading system. Recent recommendations support classifying SVI as an AAST Grade 4 (G4) injury. Our primary aim was to compare outcomes following blunt renal SVI and blunt renal collecting system lacerations (CSLs). We hypothesize that renal SVI fare well with conservative management alone and should be relegated a less severe renal AAST grade. METHODS: We retrospectively identified patients with SVI and G4 CSL admitted to a Level 1 trauma center between 2003 and 2010. Penetrating trauma was excluded. Need for surgical intervention, length of stay, kidney salvage (>25% renal preservation on renography 6-12 weeks after injury), and delayed complication rates were compared between the SVI and CSL injuries. Statistical analysis used χ, Fisher's exact, and t tests. RESULTS: A total of 56 patients with SVI and 88 patients with G4 CSL sustained blunt trauma. Age, Injury Severity Score (ISS), and length of stay were similar for the two groups. Five patients in each group died of concomitant, nonrenal injuries. In the G4 CSL group, 15 patients underwent major interventions, and 32 patients underwent minor interventions. Only one patient in the SVI group underwent a major intervention. The renal salvage rate was 85.7% following SVI versus 62.5% following CSL (p = 0.107). CONCLUSION: Overall, surgical interventions are significantly lower among the SVI cohort than the G4 CSL cohort. Further analysis using a larger cohort of patients is recommended before revising the current renal grading system. Adding SVI as a G4 injury could potentially increase the heterogeneity of G4 injuries and decrease the ability of the AAST renal injury grading system to predict outcomes, such as nephrectomy rate. LEVEL OF EVIDENCE: Epidemiologic study, level IV.

Nephrostomy in early posttransplantation period in patients with nonfunctional graft and nondilated collecting system.

BACKGROUND: The purpose of our study was to determine whether renal function can be restored by early nephrostomy in patients who fail to develop renal function immediately after transplantation. METHODS: Between 2001 and 2010, we have performed external/internal nephrostomy in 13 patients during the early posttransplant period. The reason for the procedure was graft nonfunction with oliguria/anuria in the presence of normal renal perfusion, absence of signs of rejection, and/or renal collecting system dilation. The nephrostomy was created under ultrasound/fluoroscopic guidance. RESULTS: Nephrostomy was technically successful in all cases. On days 1-3 following nephrostomy creation, 10 of 13 patients showed an increase in diuresis and subsequent graft function development. Once the obstruction had been removed, the graft remained functional for months up to years posttransplantation. Three patients failed to respond to nephrostomy. There were no nephrostomy-related complications. CONCLUSIONS: Our study documents that, in patients who failed to develop graft function posttransplant for unknown reasons, nephrostomy may result in graft function development.

Flexible ureterorenoscopy for lower pole stones: influence of the collecting system's anatomy.

BACKGROUND: The impact of renal anatomy on the success rate of flexible ureterorenoscopy (fURS) for lower pole stones is less clear than it is on shock wave lithotripsy, for which it is a recognized influence factor. We analyzed safety and efficiency of fURS using modern endoscopes for lower pole stones dependent on the collecting system's configuration. PATIENTS AND METHODS: We retrospectively evaluated a consecutive sample of 111 fURS for lower pole stones at our tertiary care center between January 2010 and September 2012 from our prospectively kept database. All procedures were performed with modern flexible ureterorenoscopes, nitinol baskets, holmium laser lithotripsy, and ureteral access sheaths whenever needed. The infundibular length (IL) and width (IW) and infundibulopelvic angle (IPA) were measured and the data were stratified for stone-free status and complications classified by the Clavien-Dindo scale. Univariate and multifactorial statistical analyses were performed. Correlation of operation time (OR-time) with anatomical parameters was conducted. RESULTS: Ninety-eight (88.3%) of the 111 patients were stone free after a single fURS. On multifactorial analysis, the stone size and IL had significant influence on the stone-free rate (SFR) (p<0.01), whereas IW did not. An acute IPA (<30°) also had significant influence (p=0.01). The incidence of complications and OR-time were not influenced by the pelvicaliceal anatomy. CONCLUSIONS: fURS is a safe and efficient treatment option for lower pole kidney stones. A long infundibulum and a very acute IPA (<30°) negatively affect the SFR. However, with second look procedures, a complete stone clearance is achievable even in case of unfavorable anatomic conditions. A narrow infundibulum has no negative effect while using modern endoscopes. The complication rate is not affected by the collecting system's anatomy.

Robotic-assisted partial nephrectomy in duplicated collecting systems in the pediatric population: techniques and outcomes.

OBJECTIVE: We present our experience with pediatric robotic-assisted laparoscopic partial nephrectomy of a nonfunctioning moiety in a duplicated system (RALPN), comparing techniques and outcomes with those previously reported in the literature. To our knowledge, this is the largest series of this surgical procedure to date. PATIENTS AND METHODS: We retrospectively reviewed all pediatric patients at our institution that had undergone RALPN from 2006 to 2012. RESULTS: Twenty-one patients underwent RALPN between 2006 and 2012. Mean patient age was 4.1 years. Mean operative time was 301 min. Mean estimated blood loss was 36 ml. Mean length of stay was 38 h. The majority of cases were performed with three laparoscopic ports. At initial follow-up ultrasound 6/21 (29%) demonstrated a fluid collection. The majority of these collections occurred in cases where the resection defect was not closed intraoperatively (42% of cases vs. 11% of cases). All fluid collections were asymptomatic and managed conservatively. CONCLUSION: RALPN is associated with low complication rates. The robotic system allows for the use of only two small robotic working ports in most cases. Postoperative fluid collections may be prevented by formal closure of the polar defect, but fluid collections that do occur can be followed conservatively.

Pediatric robotic-assisted laparoscopic ipsilateral ureteroureterostomy in a duplicated collecting system.

INTRODUCTION AND OBJECTIVE: Duplex renal collecting system is a common congenital anomaly in the pediatric population. The superior moiety ureter is often associated with an ectopic insertion. A common site of insertion is the urethra, which results in continuous incontinence. A novel repair for this abnormality is a robotic assisted laparoscopic ipsilateral ureteroureterostomy with end to side anastomosis. This teaching video will demonstrate positioning and operative technique for this procedure. PATIENT AND METHODS: This is the case of a 5-year-old girl who presented with lifelong continuous urinary incontinence. Workup revealed a duplicated collecting system with a functional superior moiety and ectopic ureter inserting into the urethra. A laparoscopic ipsilateral ureteroureterostomy was performed using a robotic surgical system. RESULTS: After docking the robotic surgical system, the duplicated collecting system was identified and an ipsilateral ureteroureterostomy was performed. The patient tolerated the procedure well and the ultrasound on follow up revealed no residual hydronephrosis. CONCLUSION: The accompanying teaching video shows appropriate positioning and operative technique for a robotic-assisted laparoscopic ureteroureterostomy. This innovative and minimally invasive technique is a safe and feasible approach to repair a duplex collecting system with an ectopic ureter in the pediatric population.

Phenotypic characterization of kidney stone formers by endoscopic and histological quantification of intrarenal calcification.

Interstitial Randall's plaques and collecting duct plugs are distinct forms of renal calcification thought to provide sites for stone retention within the kidney. Here we assessed kidney stone precursor lesions in a random cohort of stone formers undergoing percutaneous nephrolithotomy. Each accessible papilla was endoscopically mapped following stone removal. The percent papillary surface area covered by plaque and plug were digitally measured using image analysis software. Stone composition was determined by micro-computed tomography and infrared analysis. A representative papillary tip was biopsied. The 24-h urine collections were used to measure supersaturation and crystal growth inhibition. The vast majority (99%) of stone formers had Randall's plaque on at least 1 papilla, while significant tubular plugging (over 1% of surface area) was present in about one-fifth of patients. Among calcium oxalate stone formers the amount of Randall's plaque correlated with higher urinary citrate levels. Tubular plugging correlated positively with pH and brushite supersaturation but negatively with citrate excretion. Lower urinary crystal growth inhibition predicted the presence of tubular plugging but not plaque. Thus, tubular plugging may be more common than previously recognized among patients with all types of stones, including some with idiopathic calcium oxalate stones.

Collecting system percutaneous access using real-time tracking sensors: first pig model in vivo experience.

PURPOSE: Precise needle puncture of the renal collecting system is an essential but challenging step for successful percutaneous nephrolithotomy. We evaluated the efficiency of a new real-time electromagnetic tracking system for in vivo kidney puncture. MATERIALS AND METHODS: Six anesthetized female pigs underwent ureterorenoscopy to place a catheter with an electromagnetic tracking sensor into the desired puncture site and ascertain puncture success. A tracked needle with a similar electromagnetic tracking sensor was subsequently navigated into the sensor in the catheter. Four punctures were performed by each of 2 surgeons in each pig, including 1 each in the kidney, middle ureter, and right and left sides. Outcome measurements were the number of attempts and the time needed to evaluate the virtual trajectory and perform percutaneous puncture. RESULTS: A total of 24 punctures were easily performed without complication. Surgeons required more time to evaluate the trajectory during ureteral than kidney puncture (median 15 seconds, range 14 to 18 vs 13, range 11 to 16, p=0.1). Median renal and ureteral puncture time was 19 (range 14 to 45) and 51 seconds (range 45 to 67), respectively (p=0.003). Two attempts were needed to achieve a successful ureteral puncture. The technique requires the presence of a renal stone for testing. CONCLUSIONS: The proposed electromagnetic tracking solution for renal collecting system puncture proved to be highly accurate, simple and quick. This method might represent a paradigm shift in percutaneous kidney access techniques.

Tubulocystic renal carcinoma (low grade collecting duct carcinoma).

OBJECTIVE: To report a case of tubulocystic renal carcinoma diagnosed in an adult, after a work up study for hematuria. METHODS/RESULTS: 59-year-old male, CT scan was performed during a study for self-limited hematuria showing a 4.2 cm solid mass with areas suspicious of pseudocystic malignancy. Due to its debut with hematuria and renal sinus involvement laparoscopic radical nephrectomy was performed, establishing the diagnosis of tubulocystic carcinoma (low grade collecting duct carcinoma). CONCLUSION: Tubulocystic carcinoma presents histological characteristics and a natural history that makes it different from the classic type of Bellini duct carcinoma, the latter being a rapidly growing tumor with poor prognosis which is usually diagnosed in advanced stages.

Robot-assisted upper pole nephrectomy in adult patients with duplicated renal collecting systems.

Duplicated renal collecting systems are a common congenital anomaly, with patients usually presenting in childhood, rarely in adult life. To our knowledge, only one case of robot-assisted heminephrectomy in adults has been described. We reviewed the medical records of four adult patients with symptomatic unilateral duplicated collecting systems and nonfunctioning upper pole renal units (NFUPRU) who underwent robot-assisted laparoscopic heminephrectomy at our institutions. Heminephrectomy for NFUPRU should be approached differently than partial nephrectomy, because of complex vascular anatomy. Patients who are undergoing this procedure have brief hospital stays, minimal morbidity, preservation of renal function, and resolution of symptoms. Robot-assisted laparoscopy is well suited for this procedure because it allows improved visualization during dissection of the unique vascular anatomy as well as scaling of surgeon movements and improved ergonomics.

Hand-assisted laparoscopic partial nephrectomy without formal collecting system closure: perioperative outcomes in 104 consecutive patients.

BACKGROUND AND PURPOSE: Laparoscopic partial nephrectomy (LPN) paralleling open techniques, particularly closure of the collecting system, can be technically challenging for the novice laparoscopist. We describe operative results and complications of a single surgeon, retrospectively reviewed series using a simplified method of hand assistance and a fibrin glue patch for hemostasis without formal collecting system closure. PATIENTS AND METHODS: We identified 104 consecutive patients between September 2003 and January 2009 who underwent hand-assisted laparoscopic partial nephrectomy (HALPN). Our technique involves routine hilar clamping after isolation of the tumor and mobilization of the kidney. After resection of the mass, a fibrin glue patch is placed within the surgical defect and secured with bolstering sutures. No attempt is made to suture the collecting system, nor are ureteral catheters placed when the collecting system is entered during resection of the tumor. RESULTS: Mean tumor size was 2.8 cm (median 2.5 cm, range 0.7-7.0 cm). With hilar clamping, warm ischemia time averaged 24.5 minutes (range 11-39 min). Estimated blood loss averaged 220 mL (range 50-1500 mL), and five (4.8%) patients received transfusions either intraoperatively or postoperatively. Urine leak occurred in 1.9% (n=2) of patients overall and 4.3% (2/47) of patients with documented collecting system entry. Both urine leaks resolved with conservative management only. CONCLUSIONS: HALPN without formal collecting system closure is a safe and effective technique with similar urine leak and transfusion rates compared with other series. This technique may allow more urologists to perform minimally invasive partial nephrectomy or to do so with potentially shorter ischemia times.