MMP9 overexpression is associated with good surgical outcome in children with UPJO: Preliminary results.

BACKGROUND: Ureteropelvic junction obstruction (UPJO) diagnosed prenatally occurs in 1:150 - 1:1200 pregnancies. Although many studies investigating the molecular changes of this obstructed segment have been performed, the underlying mechanisms are still unclear. The role of extracellular matrix (ECM) components remains controversial, and the investigations in the field of ECM changes, might help the better understanding of the pathogenesis of this common condition. The aim of the present study was to investigate for the first time in the literature whether MMP9 and its specific inhibitors, TIMP1 and RECK, are expressed in a reproducible, specific pattern in UPJ. METHODS: UPJO specimens were obtained from 16 children at the time of dismembered pyeloplasty due to intrinsic UPJ stenosis. Expression levels of the three genes (MMP9, TIMP1 and RECK) were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). Then correlated the expression levels of the genes according to grade study population that was divided in 2 categories according to Society of Fetal Urology classification, grade 3 (moderate) and 4 (severe). For DTPA we subdivided the childrens in 2 groups, obstructive (T 1/2 more than 20 min) and partial obstructive (T 1/2 between 10 and 20 min) and success in a surgery was defined as decrease in T 1/2 to less than 20 min, absence of symptoms, improving renal function and decreasing dilatation on successive exams. RESULTS: MMP9 was underexpressed and TIMP1 and RECK were overexpressed in children with obstructive DTPA but the differences were not statistically significant. Overexpression of MMP9 was higher among patients with severe grade of UPJ compared to those with moderate grade. Surprisingly expression levels of MMP-9 was three times higher in children who were successfully treated by surgery (n = 10) (p = 0.072), so those who were followed for at least 1 year after surgery and remained with improvement in renal function and decreasing dilation on intravenous urogram and TIMP-1 was underexpressed in 100 % of this cases (p = 0.00). CONCLUSIONS: We showed an increase in expression of MMP9 and a decrease in expression of TIMP1 in children who improving renal function and decreasing dilation after surgery. We believe that the higher expression of MMP9 in these cases can reflect an increase in degradation and remodeling process that could be used as a marker for surgical outcome.

PCNL vs. two staged RIRS for kidney stones greater than 20 mm: systematic review, meta-analysis, and trial sequential analysis.

INTRODUCTION: Percutaneous nephrolithotomy (PCNL) is considered the gold standard treatment for kidney stones greater than 20 mm. However, retrograde intrarenal surgery (RIRS) may achieve the same stone-free rate with repeated procedures, and potentially fewer complications. This study aimed to compare the efficacy and safety of PCNL and two-staged RIRS. EVIDENCE ACQUISITION: We conducted a systematic search in PubMed, Embase, Scopus, Cochrane, and Web of Science for studies comparing PCNL and RIRS for kidney stones greater than 20mm. The primary outcome is stone-free rate (SFR) of PCNL and RIRS (repeated once if needed). Secondary outcomes were SFR of PCNL versus RIRS (single procedure), operative time, hospital stay, need for auxiliary procedures, and complications. We performed a subgroup analysis for randomized trials, non-randomized trials, and patients with solitary kidney. We performed a trial sequential analysis for the main outcome. EVIDENCE SYNTHESIS: We included 31 articles, with 1987 patients in the PCNL and 1724 patients in RIRS. We confirmed the traditional result that after a single procedure PCNL has a higher SFR. We also found that comparing the SFR of PCNL and RIRS, repeated up to two times if needed, no difference in SFR was observed. Surprisingly, only 26% (CI95 23%-28%) of the patients required a second RIRS. In the trial sequential analysis, the last point of the z-curve was within futility borders. We observed that PCNL has a higher incidence of complications (RR=1.51; CI95 1.24, 1.83; P<0.0001; I2=28%), specifically CD2 (RR=1.82; CI95 1.30, 2.54; P=0.0004; I2=26%) and longer hospital stay (MD 2.57; 2.18, 2.96; P<0.00001; I2-98%). No difference was observed regarding operative time. CONCLUSIONS: RIRS repeated up to two times is equivalent to PCNL in terms of the SFR and may have the same safety.

Effect of irrigation solution temperature on complications of percutaneous nephrolithotomy: a systematic review of the literature, meta-analysis and trial sequential analysis of randomized clinical trials.

INTRODUCTION: The optimal temperature of irrigation solution in patients undergoing PCNL is still unclear. Accordingly, this study aims to investigate the effects of different irrigation solution temperatures (cold/room temperature irrigation fluid versus warm/body temperature fluid). Our primary endpoint was hypothermia rate. Secondary outcomes were shivering rate, mean temperature decrease, mean patient final temperature, blood loss, and operative time. EVIDENCE ACQUISITION: This systematic review was conducted in accordance with PRISMA guidelines. Multiple databases were searched in November 2023. Among 299 studies screened, eight were selected for full-text review, resulting in four randomized clinical trials that fit inclusion criteria and desired outcomes. Studies selection and data extraction were performed by multiple reviewers and a random-effects model was used for pooling of data. EVIDENCE SYNTHESIS: The primary outcome, hypothermia rate, showed a significant statistical difference between groups, occurring less frequently in the experimental group (35-37 ºC) than in the cold/room temperature irrigation group (RR 0.64;95%CI 0.46, 0.89; P<0.008; I2=33%). Secondary outcomes such as shivering rate (RR 0.46; 95%CI 0.31, 0.67; P<0.0001; I2=0%) and mean final temperatures (MD 0.43; 95%CI 0.12, 0.75; I2=82%) also showed statistically significant differences between groups, favoring the irrigation with heated fluid. CONCLUSIONS: There was a decreased rate of hypothermia and shivering among patients undergoing PCNL with warm irrigation fluid. Mean final temperatures were also higher in the experimental group. As to blood loss, mean hemoglobin decrease showed no statistically significant difference between groups, prompting further investigation of the influence of Irrigation solution temperature on blood loss volume.

Parent and patient perceptions of robotic vs open urological surgery scars in children.

PURPOSE: Cumulative evidence shows that robot-assisted laparoscopic surgery is safe and at least as efficacious as open surgery for several pediatric urological procedures. Scars resulting from robotic surgery are often assumed to have a cosmetic advantage. However, no study has clearly demonstrated that parents and patients consistently prefer such scars. MATERIALS AND METHODS: We developed 3 distinct surveys consisting of photographs and diagrams of scars resulting from open and robot-assisted laparoscopic surgery for ureteral reimplantation, pyeloplasty and bladder augmentation. Surveys were distributed to parents of patients being evaluated for 1 of the 3 procedures. The surveys evaluated information such as scar preference, reason for preference and demographics. Patients older than 7 years also completed surveys. RESULTS: Robot-assisted laparoscopic surgical scars were preferred by parents for all procedures studied (85% for ureteral reimplant, 63% for pyeloplasty and 93% for bladder augmentation). Patients also preferred the robotic scars (76%, 62% and 91%, respectively). Patients and parents did not differ significantly in scar preference or in rating of factors affecting decision. Scar size was important or very important to 80% of parents for reimplant, 83% for pyeloplasty and 86% for bladder augmentation. However, the majority of parents would ultimately base their choice of surgical approach on clinical efficacy rather than scar preference. CONCLUSIONS: Parents and patients prefer robot-assisted laparoscopic surgical scars to open surgical scars for pediatric ureteral reimplantation, pyeloplasty and bladder augmentation. Scar appearance is an important influence on the decisions of parents and patients, and should be discussed when surgical treatment is presented.

Development and initial validation of a scoring system to diagnose testicular torsion in children.

PURPOSE: Testicular torsion is a surgical emergency requiring prompt intervention. Although clinical diagnosis is recommended, scrotal ultrasound is frequently ordered, delaying treatment. We created a scoring system to diagnose testicular torsion, decreasing the indication for ultrasound. MATERIALS AND METHODS: We prospectively evaluated 338 patients with acute scrotum, of whom 51 had testicular torsion. Physical examination was performed by a urologist, and all patients underwent scrotal ultrasound. Univariate analysis and logistic regression were performed, and a scoring system for risk stratification of torsion was created. Retrospective validation was performed with 2 independent data sets. RESULTS: The scoring system consisted of testicular swelling (2 points), hard testicle (2), absent cremasteric reflex (1), nausea/vomiting (1) and high riding testis (1). Cutoffs for low and high risk were 2 and 5 points, respectively. Ultrasound would be indicated only for the intermediate risk group. In the prospective data set 69% of patients had low, 19% intermediate and 11.5% high risk. Negative and positive predictive values were 100% for cutoffs of 2 and 5, respectively (specificity 81%, sensitivity 76%). Retrospective validation in 1 data set showed 66% of patients at low, 16% intermediate and 17% high risk. Negative and positive predictive values for cutoffs of 2 and 5 were 100% (specificity 97%, sensitivity 54%). The second retrospective data set included only torsion cases, none of which was misdiagnosed by the scoring system. CONCLUSIONS: This scoring system can potentially diagnose or rule out testicular torsion in 80% of cases, with high positive and negative predictive values for selected cutoffs. Ultrasound orders would be decreased to 20% of acute scrotum cases. Prospective validation of this scoring system is necessary.

Variations in management of mild prenatal hydronephrosis among maternal-fetal medicine obstetricians, and pediatric urologists and radiologists.

PURPOSE: There are no current guidelines for diagnosing and managing mild prenatal hydronephrosis. Variations in physician approach make it difficult to analyze outcomes and establish optimal management. We determined the variability of diagnostic approach and management regarding prenatal hydronephrosis among maternal-fetal medicine obstetricians, pediatric urologists and pediatric radiologists. MATERIALS AND METHODS: Online surveys were sent to mailing lists for national societies for each specialty. Participants were surveyed regarding criteria for diagnosing mild prenatal hydronephrosis and recommendations for postnatal management, including use of antibiotic prophylaxis, followup scheduling and type of followup imaging. RESULTS: A total of 308 maternal-fetal medicine obstetricians, 126 pediatric urologists and 112 pediatric radiologists responded. Pediatric urologists and radiologists were divided between Society for Fetal Urology criteria and use of anteroposterior pelvic diameter for diagnosis, while maternal-fetal medicine obstetricians preferred using the latter. For postnatal evaluation radiologists preferred using personal criteria, while urologists preferred using anteroposterior pelvic diameter or Society for Fetal Urology grading system. There was wide variation in the use of antibiotic prophylaxis among pediatric urologists. Regarding the use of voiding cystourethrography/radionuclide cystography in patients with prenatal hydronephrosis, neither urologists nor radiologists were consistent in their recommendations. Finally, there was no agreement on length of followup for mild prenatal hydronephrosis. CONCLUSIONS: We observed a lack of uniformity regarding grading criteria in diagnosing hydronephrosis prenatally and postnatally among maternal-fetal medicine obstetricians, pediatric urologists and pediatric radiologists. There was also a lack of agreement on the management of mild intermittent prenatal hydronephrosis, resulting in these cases being managed inconsistently. A unified set of guidelines for diagnosis, evaluation and management of mild intermittent prenatal hydronephrosis would allow more effective evaluation of outcomes.

Anatrophic nephrotomy as nephron-sparing approach for complete removal of intraparenchymal renal tumors.

OBJECTIVE: Partial nephrectomy for small kidney tumors has increased in the last decades, and the approach to non-palpable endophytic tumors became a challenge, with larger chances of positive margins or complications. The aim of this study is to describe an alternative nephron-sparing approach for small endophytic kidney tumors through anatrophic nephrotomy. PATIENTS AND METHODS: A retrospective analysis of patients undergoing partial nephrectomy at our institution was performed and the subjects with endophytic tumors treated with anatrophic nephrotomy were identified. Patient demographics, perioperative outcomes and oncological results were evaluated. RESULTS: Among the partial nephrectomies performed for intraparenchymal tumors between 06/2006 and 06/2010, ten patients were submitted to anatrophic nephrotomy. The mean patient age was 42 yrs, and the mean tumor size was 2.3 cm. Mean warm ischemia time was 22.4 min and the histopathological analysis showed 80% of clear cell carcinomas. At a mean follow-up of 36 months, no significant creatinine changes or local or systemic recurrences were observed. CONCLUSION: The operative technique described is a safe and effective nephron-sparing option for complete removal of endophytic renal tumors.

Long-term experience and outcomes of robotic assisted laparoscopic pyeloplasty in children and young adults.

PURPOSE: Laparoscopic pyeloplasty is one of the more common robotic assisted procedures performed in children. However, data regarding long-term experience and clinical outcomes for this procedure are limited. We evaluated the long-term outcomes in a large series of patients undergoing robotic assisted laparoscopic pyeloplasty at a teaching institution, and the effect of a collaborative program between the robotic surgeons, surgical nurses and anesthesiologists on overall operative time. MATERIALS AND METHODS: We retrospectively reviewed 155 patients who underwent robotic assisted laparoscopic pyeloplasty between 2002 and 2009. Operative data, including surgical approach, type of procedure, total and specific operative times and placement of ureteral stents, were determined. Postoperative outcome measurements, including duration of hospital stay, duration of Foley catheter drainage, radiological findings and any subsequent complications, were assessed. RESULTS: Mean operative time and length of hospitalization decreased significantly by the end of the study. At a mean followup of 31.7 months the primary success rate was 96% (hydronephrosis was improved in 85% of patients and stable in 11%). The complication rate was 11%, and recurrent obstruction requiring redo robotic assisted laparoscopic pyeloplasty or open pyeloplasty developed in 3% of patients. Success rate and complication rate were unchanged during the study period. CONCLUSIONS: This study confirms that even within the confines of a pediatric urology training program successful collaboration between robotic surgeons, surgical nurses and anesthesiologists can lead to shorter operative times and hospital stays. Long-term surgical success and complication rates were comparable to open surgery.

Robotic assisted laparoscopic ureteral reimplantation in children: case matched comparative study with open surgical approach.

PURPOSE: Surgical treatment may be required in some patients with vesicoureteral reflux. With the recent development of robotic assistance, laparoscopic treatment of vesicoureteral reflux has gained popularity. We sought to evaluate our initial experience with pediatric robotic assisted laparoscopic intravesical and extravesical ureteral reimplantation, and to compare outcomes with the open technique. MATERIALS AND METHODS: A retrospective chart review was performed on all patients who underwent robotic assisted laparoscopic ureteral reimplantation between 2007 and 2010. Comparisons were made with a case matched cohort of patients who underwent the open technique. The groups were compared using t tests for numerical variables and chi-square comparisons or Fisher's exact test for categorical variables. A Kaplan-Meier model was used to compare success rates. RESULTS: A total of 19 patients underwent intravesical and 20 underwent extravesical robotic assisted laparoscopic ureteral reimplantation during the study period. They were compared to 22 patients undergoing intravesical and 17 undergoing extravesical open ureteral reimplantation. Although the robotic assisted approach was associated with a longer operative time (p <0.001), children undergoing intravesical robotic assisted reimplantation had a shorter duration of urinary catheter drainage, fewer bladder spasms and a shorter hospital stay compared to those undergoing the intravesical open technique (p <0.01). There were no significant differences in these parameters when comparing extravesical robotic assisted reimplantation to the extravesical open technique. Overall success rates were similar among patients who underwent robotic assisted laparoscopic ureteral reimplantation and open reimplantation (p >0.5). CONCLUSIONS: Robotic assisted laparoscopic ureteral reimplantation offers similar success rates to the gold standard, open ureteral reimplantation. Future large scale studies will be required to define further the costs and benefits of robotic assisted laparoscopic ureteral reimplantation in the surgical treatment of vesicoureteral reflux.

Identifying ureteropelvic junction obstruction by fluorescence imaging: a comparative study of imaging modalities to assess renal function and degree of obstruction in a mouse model.

PURPOSE: Radiological imaging is the mainstay of diagnosing ureteropelvic junction obstruction. Current established radiological modalities can potentially differentiate the varying degrees of obstruction but they are limited in functionality, applicability and/or comprehensiveness. Of particular concern is that some tests require radiation, which has long-term consequences, especially in children. MATERIALS AND METHODS: We investigated the novel use of Genhance™ 680 dynamic fluorescence imaging to assess ureteropelvic junction obstruction in 20 mice that underwent partial or complete unilateral ureteral obstruction. Ultrasound, mercaptoacetyltriglycine renography, magnetic resonance imaging and fluorescence imaging were performed. RESULTS: Our model of partial and complete obstruction could be distinguished by ultrasound, mercaptoacetyltriglycine renography and magnetic resonance imaging, and was confirmed by histological analysis. Using fluorescence imaging distinct vascular and urinary parameters were identified in the partial and complete obstruction groups compared to controls. CONCLUSIONS: Fluorescence imaging is a feasible alternative radiological imaging modality to diagnose ureteropelvic junction obstruction. It provides continuous, detailed imaging without the risk of radiation exposure.

Robotically assisted laparoscopic radical prostatectomy induces lower tissue trauma than radical retropubic prostatectomy.

To compare tissue trauma between Retropubic Radical Prostatectomy and Robotically Assisted Laparoscopic Radical Prostatectomy by inflammatory mediators. Serum samples from 40 patients submitted to RALP and 20 patients submitted to RRP were withdrawn at four different time points. The cytokines IL-4, IL-8, IL-6, IL-1B, IL-10 and TNF-α were detected using ELISA/Multiplex assays and xMAP-Luminex®. With both techniques, IL-10 and IL-6 were higher in T4 than in T1-T3 (p = 0.001). IL-10 and IL-6 were higher in T4 in open surgery than in robotic surgery (p = 0.000 and p = 0.001, respectively). Compared with both groups, IL-6 and IL-10 were higher in T4 in open surgery than in robotic surgery. Thus, we can postulate that RALP causes less tissue trauma than classical RRP, as indicated by the more limited increase in inflammatory mediators such as IL-6 and IL-10.

Improvement in vesicoureteral reflux grade on serial imaging predicts resolution.

PURPOSE: When children are initially diagnosed with vesicoureteral reflux most undergo a period of antibiotic prophylaxis followed by serial imaging. Although improvement in reflux grade through time presumably predicts eventual resolution, the significance of changing grade through time is unknown. We examined whether improvement in reflux on serial imaging predicts resolution. MATERIALS AND METHODS: We retrospectively reviewed 1,761 children diagnosed with vesicoureteral reflux, of whom 965 had a minimum of 2 years of followup. We examined initial reflux grade and grade on serial imaging up to 5 years after the original diagnosis. For each child it was determined whether reflux was resolved, eventually resolved or never resolved. Groups were further stratified by clinical characteristics. RESULTS: Multivariate analysis revealed that male gender (HR 1.33, p = 0.05), age younger than 1 year at diagnosis (HR 1.35, p = 0.004), lower grade at presentation (grade I HR 2.2, grade II HR 1.96, grade III HR 1.33; p <0.001) and unilateral reflux (HR 1.39, p = 0.001) were all independent predictors of reflux resolution. Multivariate analysis also showed that reflux improvement on imaging 1 year after diagnosis (HR 3.14, p <0.0001) and improvement from the previous year at any point during followup (HR 1.8, p = 0.009) were independent predictors of reflux resolution. CONCLUSIONS: Consistent with previous findings, male gender, lower reflux grade at presentation, age less than 1 year at presentation and unilateral reflux were all predictive of reflux resolution. Our analysis also demonstrated that improvement in reflux grade on imaging study 1 year after diagnosis was predictive of resolution, and that reflux improvement from the previous year at any point during followup was an independent predictor of resolution. This information will prove valuable in clinical counseling and therapeutic decision making.

Reconstructive laparoscopy in pediatric urology.

PURPOSE OF REVIEW: Minimally invasive surgery used to play a role only as a diagnostic tool in pediatric urology, being used in a narrow range of conditions like cryptorchidism. With the breakthrough of laparoscopic techniques, skilled surgeons and remarkably the advances in robotic-assisted surgery, laparoscopy has gained a role for treatment purposes in pediatric urology. RECENT FINDINGS: Many reconstructive laparoscopic procedures notably with the aid of robotic-assisted surgery such as pyeloplasty and ureteral reimplantation and even more challenging procedures like appendicovesicostomy became feasible with similar results to those with open surgery. Even though minimally invasive approaches may have the drawback of greater technical difficulty, they have the advantages of shorter hospital stays, lesser postoperative pain and better cosmesis. SUMMARY: There is still a lack of controlled prospective randomized trials assessing the differences between open and minimally invasive techniques for reconstructive pediatric urology. Nevertheless, the minimally invasive approach has proven itself to be feasible and well tolerated for most reconstructive procedures.

Robotic assisted laparoscopic Mitrofanoff appendicovesicostomy: preliminary experience in a pediatric population.

PURPOSE: Continent urinary diversion has a central role in treating various urinary tract conditions and traditionally has been performed as an open procedure. We report on 10 patients who underwent a robotic assisted laparoscopic Mitrofanoff procedure using the da Vinci surgical system. MATERIALS AND METHODS: Patients had bladder dysfunction of various etiologies, including posterior urethral valves and neurogenic bladder. Preoperatively all patients unsuccessfully attempted clean intermittent catheterization via the urethra. RESULTS: Mean operative time was 323 minutes (range 181 to 507). One case was converted to open surgery secondary to an inadequate appendix discovered intraoperatively. Mean estimated blood loss was 48.4 cc (range 5 to 200). Median hospitalization was 5 days. Median followup was 14.2 months. Urinary leakage developed postoperatively in 1 patient, requiring an open revision. Minor incontinence developed in 2 cases, of which 1 was corrected with dextranomer/hyaluronic acid injection and 1 resolved without intervention. CONCLUSIONS: The robotic assisted laparoscopic Mitrofanoff procedure is feasible to perform, is associated with satisfactory outcomes and minimal complications, and has the benefits of a minimally invasive approach.

Robot assisted laparoscopic partial nephrectomy: a viable and safe option in children.

PURPOSE: The safety, benefits and usefulness of laparoscopic partial nephrectomy have been demonstrated in the pediatric population. We describe our technique, and determine the safety and feasibility of robot assisted laparoscopic partial nephrectomy based on our initial experience. MATERIALS AND METHODS: We retrospectively reviewed robot assisted laparoscopic partial nephrectomy performed at our institution between 2002 and 2005. The technique was conducted via a transperitoneal approach with the da Vinci Surgical System using standard laparoscopic procedural steps. Clinical indicators of outcomes included estimated blood loss, complications, in hospital narcotic use and length of stay. RESULTS: Robot assisted laparoscopic partial nephrectomy was completed successfully in 9 cases. Mean patient age was 7.2 years and mean followup was 6 months. Mean operative time was 275 minutes and mean estimated blood loss was 49 ml. Operative times improved significantly with experience. Overall patients had a mean hospitalization of 2.9 days and required 1.3 mg morphine per kg. All patients had a normal remaining renal moiety confirmed on Doppler ultrasound. The only complication was an asymptomatic urinoma discovered on ultrasound, which was treated with percutaneous drainage and ultimately resolved. CONCLUSIONS: Our initial experience shows the safety and feasibility of robot assisted laparoscopic partial nephrectomy in children. Operative time decreases with experience. The enhanced visualization and dexterity of a robotic system potentially offer improved efficiency and safety over standard laparoscopy. Robot assisted laparoscopy is an option for partial nephrectomy and may become the minimally invasive treatment of choice.

Nomograms for predicting annual resolution rate of primary vesicoureteral reflux: results from 2,462 children.

PURPOSE: We determined the resolution rate of vesicoureteral reflux and the factors that influence it to formulate nomograms to predict the probability of annual resolution for individual cases of reflux. MATERIALS AND METHODS: We studied 2,462 children with primary vesicoureteral reflux diagnosed between 1998 and 2006. Cox proportional hazards regression was used to model time to resolution as a function of statistically significant demographic and clinical variables. The resulting model was used to construct nomograms predicting the annual cumulative probability of reflux resolution. RESULTS: Multivariate analysis showed that all cases of unilateral reflux resolved earlier than female bilateral reflux (HR 1.42, p <0.001). Additionally age less than 1 year at presentation (HR 1.31, p <0.001), lower reflux grade (2.96, p <0.001 for grade I; 2.28, p <0.001 for grade II; 1.63, p <0.001 for grade III), reflux diagnosed on postnatal evaluation for prenatal hydronephrosis or sibling screening (1.24, p = 0.002) and single ureter (1.55, p <0.001) were associated with significantly earlier resolution of reflux. Specific predicted cumulative probabilities of reflux resolution at annual intervals from diagnosis (1 to 5 years) were calculated for every possible combination of the significant variables. CONCLUSIONS: Our analyses demonstrate that resolution of vesicoureteral reflux is dependent on age at presentation, gender, grade, laterality, mode of clinical presentation and ureteral anatomy. We constructed nomogram tables containing estimates of annual reflux resolution rate as a function of these variables. This information is valuable for clinical counseling and management decisions.

Patterns and predictors of laparoscopic complications in pediatric urology: the role of ongoing surgical volume and access techniques.

PURPOSE: Laparoscopic surgery in children has evolved to include complex reconstructive procedures. While complication rates are low, they can have significant consequences. In this study we define the incidence and risk factors for complications in children undergoing laparoscopic urological surgery. MATERIALS AND METHODS: We conducted a retrospective analysis of all conventional and robot assisted laparoscopic urological procedures performed at our institution from 1995 to 2005. Complications were graded based on Clavien's classification. Statistical analysis was performed using the t test and Fisher's exact test. RESULTS: A total of 806 laparoscopic procedures were evaluated. Overall, there was a 2% complication rate, including 1.6% for access related and 0.7% for procedural complications (in 440 nondiagnostic cases). Complications related to access occurred in 9 of 396 cases (2.3%) using Veress access, compared to 3 of 389 cases (0.8%) using open access (p = 0.14). The incidence of grades III and IV complications was identical between techniques (0.8%). Complications included preperitoneal insufflation sufficient to necessitate conversion to an open procedure (0.7%), vessel injury (0.4%), small bowel injury (0.4%), bleeding requiring conversion (0.1%), bladder perforation (0.1%) and vas deferens injury (0.2%). Surgeons performing more than 12 laparoscopic cases annually had a significantly lower complication rate (p = 0.024). CONCLUSIONS: The low risk of complications demonstrated in this series confirms that laparoscopic procedures are safe, although there remains a risk of significant injury. Determinants of surgical outcome include laparoscopic activity, and to a lesser extent access technique. Most if not all complications are preventable with proper adherence to technique and ongoing education.

A novel method of imaging calcium urolithiasis using fluorescence.

PURPOSE: In the surgical management of urolithiasis the goal of treatment is not only to remove calculi, but also prevent future stone formation by rendering the patient stone-free/fragment-free. Achieving this goal is often difficult with endoscopic procedures due to the inability to visualize small calculi well even with x-ray or ultrasound. We evaluated fluorescence probes as a novel method of identifying calculi in the urinary tract. MATERIALS AND METHODS: In vitro calcium stones were incubated with each of the Osteosense 680 and Osteosense 750 calcium binding fluorescence probes, and imaged with a near infrared fluorescence imaging system. Using a mouse model calculi were placed in the renal pelvis and the probes were injected intravenously. Imaging was performed at various times after injection. RESULTS: In vitro the Osteosense 680 probe demonstrated high binding affinity for calcium oxalate-struvite, calcium phosphate-struvite and ammonium urate-calcium oxalate-calcium phosphate stones, and lower binding affinity for the calcium phosphate stone. In contrast, the Osteosense 750 probe demonstrated high binding affinity for calcium oxalate-struvite and calcium phosphate-struvite stones, and lower binding affinity for calcium phosphate and ammonium urate-calcium oxalate-calcium phosphate stones. In vivo intravenous administration of the probes was successful in labeling all calcium stone types tested. CONCLUSIONS: Fluorescence imaging provides a new method for identifying calculi in the urinary tract. The improved visualization of these stones/fragments would make endoscopic procedures less difficult, decrease the risk of complications and increase the chance of rendering the patient stone-free/fragment-free.

In utero treatment for bladder outlet obstruction using robot assisted laparoscopic techniques.

PURPOSE: Bladder outlet obstruction can have devastating consequences. Given the poor outcome, intervention in utero has been advocated in an attempt to salvage pulmonary and renal function. We evaluated whether laparoscopic decompression of the obstructed bladder could be performed efficiently by adapting current robot assisted laparoscopic techniques to access the fetus in utero. MATERIALS AND METHODS: At 95 days of gestation 20 fetal sheep underwent ligation of the urethra and urachus. Two to 5 days later robot assisted laparoscopic vesicostomy was performed. Ultrasound of the kidneys and bladder was performed before each procedure. At 135 days of gestation the urinary tract was evaluated to assess the adequacy of bladder decompression and a patent vesicostomy. RESULTS: After 48 hours of undergoing ligation all fetuses had bilateral moderate hydronephrosis and a markedly distended bladder. In the first 10 fetuses vesicostomy could not be completed laparoscopically due to limited visualization. Additional modifications in trocar placement and gas infusion allowed vesicostomy to be completed laparoscopically in the last 8 fetuses in 2.5 to 4 hours. Urinary tract decompression and a patent vesicostomy were observed in all of these fetuses postoperatively. CONCLUSIONS: We developed specific modifications in current robot assisted laparoscopic techniques and instrumentation to allow the treatment of bladder outlet obstruction in utero. This procedure may be performed efficiently and it may provide advantages over conventional surgery for fetal intervention.

Robot-assisted laparoscopic ureteroureterostomy: description of technique.

BACKGROUND AND PURPOSE: With the development of robotic assistance, laparoscopic surgery has evolved over the past few years. Smaller instruments, better visibility, and growing surgical experience have allowed more complex reconstructive procedures to be performed laparoscopically. Herein, we describe our technique and experience in robot-assisted laparoscopic ureteroureterostomy (RALU) for the correction of ureteral obstruction in children. TECHNIQUE: RALU was performed in three children through a transperitoneal approach utilizing three ports. We describe our preference for patient positioning, robotic set-up, port placement, the use of a "hitch stitch," and the option of placing a fourth port. CONCLUSIONS: RALU is a reliable and efficient technique for the correction of ureteral obstruction in children and can be applied to any pathology that requires ureteral reconstruction, regardless if it is a duplicated or a single system.