Management of Splenic Injury During Percutaneous Nephrolithotomy: Report of Two Cases.

Percutaneous nephrolithotomy (PCNL) has become the standard of care for the removal of kidney stones >2 cm. Major complications, although rare, are between 1% and 7%. Splenic injury during PCNL is rare and can often be managed conservatively, but has the potential to be devastating, necessitating the importance of early diagnosis. Our team describes two cases of splenic injury during PCNL with emphasis on diagnosis and management. Although both cases were managed conservatively through close monitoring and prolonged nephrostomy tube presence, one case had a concurrent pneumothorax. Both cases were diagnosed primarily through postprocedure CT imaging. Risk factors primarily include supracostal access and splenomegaly. Splenic injury is a rare complication that can often be managed conservatively; however, prompt recognition of injury is important. We present in this study two cases of conservative splenic injury management sustained during PCNL.

Endoscopic Management of Upper Urinary Tract Urothelial Carcinoma.

INTRODUCTION: Endoscopic management of upper tract urothelial carcinoma has become more popular over the last few decades as there has been an impetus for renal preservation in these patients. While radical nephroureterectomy has been the gold standard in treatment of this disease, ureteroscopic and percutaneous management has become a viable option for select patients. METHODS AND MATERIALS: The literature on endoscopic management of upper urinary tract tumors was explored. Different management methods are discussed, both from published literature and experience of the authors of this chapter. RESULTS: We review the indications, details of the procedure, and troubleshooting methods in the endoscopic management of upper tract urothelial carcinoma. Imperative indications as well as controversial indications are discussed. The role and efficacy of adjuvant intrarenal topical agents are examined as well as the protocol for administering these agents. Follow-up protocols are also reviewed. DISCUSSION: In select patients, endoscopic management with ureteroscopy and/or percutaneous resection of upper tract urothelial tumors is appropriate and can preserve renal function while obtaining comparable oncologic control compared with radical surgery.

The genetic framework for development of nephrolithiasis.

Over 1%-15% of the population worldwide is affected by nephrolithiasis, which remains the most common and costly disease that urologists manage today. Identification of at-risk individuals remains a theoretical and technological challenge. The search for monogenic causes of stone disease has been largely unfruitful and a technological challenge; however, several candidate genes have been implicated in the development of nephrolithiasis. In this review, we will review current data on the genetic inheritance of stone disease, as well as investigate the evolving role of genetic analysis and counseling in the management of nephrolithiasis.

Renal functional outcomes are not adversely affected by selective angioembolization following percutaneous nephrolithotomy.

OBJECTIVE: Selective angioembolization (SAE) effectively diagnoses and treats iatrogenic vascular complications following percutaneous nephrolithotomy (PCNL). METHODS: We retrospectively reviewed 1329 consecutive PCNLs and identified patients who underwent SAE following PCNL with at least 12-month follow-up. Estimated glomerular filtration rate (eGFR) was calculated for all patients preoperatively, postoperatively and at last follow-up. A 1:2 matched cohort analysis was performed. RESULTS: Twenty-three patients underwent SAE and matched to 46 controls. There was no statistically significant difference in preoperative, postoperative, and follow-up eGFR when comparing patients who underwent SAE and those with an uneventful course. CONCLUSION: Long-term eGFR is comparable in patients who undergo uncomplicated PCNL and those requiring SAE.

Rigid-only versus combined rigid and flexible percutaneous nephrolithotomy: a systematic review.

INTRODUCTION: Percutaneous nephrolithotomy (PNL) is usually performed worldwide with a rigid-only antegrade approach. Daily practice suggests that adding flexible nephroscopy and/or ureteroscopy to conventional rigid PNL might improve its efficacy and safety, but available evidence is weak. Appraisal of reliable outcomes of such PNL techniques would better guide intraoperative choices and optimize surgical results. Therefore, our objective was to systematically review relevant literature comparing the outcomes of rigid-only PNL and combined flexible PNLs (adding flexible nephroscopy and/or flexible ureteroscopy) for the treatment of large and/or complex upper urinary tract calculi, with regard to efficacy and safety. EVIDENCE ACQUISITION: Ovid MedLine, PubMed, Scopus and Web of Science databases were searched in August 2016 to identify relevant studies. Article selection was performed according to the Preferred Reporting Items for Systematic Review and Meta-analysis criteria. EVIDENCE SYNTHESIS: Six articles reporting on 666 patients were included: two randomized controlled trials, two retrospective comparative studies and two case series ≥50 patients (one prospective and one retrospective). A narrative synthesis of minor evidences was also prepared. The adjunct of flexible nephroscopy and/or ureteroscopy provided better stone-free rates (range 86.7-96.97%), through a single percutaneous access most of the times and in any position, reducing the need for second-look procedures. Safety of the combined flexible procedures was improved to a variable degree, with a consensual reduction of the mean hospital stay (range 5.1-7 days). CONCLUSIONS: The current evidence suggests that patients with large and/or complex urolithiasis might benefit from the adjunct of flexible nephroscopy and/or ureteroscopy to rigid PNL.

Minimally Invasive Therapy for Upper Tract Urothelial Cell Cancer.

Minimally invasive therapy for upper tract urothelial cell cancer has assumed an important role in the management of this relatively uncommon genitourinary malignancy. In this review, current standards for patient selection, surgical approach, as well as overall outcomes will be discussed. Moreover, the use of intraluminal agents in upper tract disease is examined along with its efficacy and associated complications.

A Randomized Controlled Comparison of Nephrostomy Drainage vs Ureteral Stent Following Percutaneous Nephrolithotomy Using the Wisconsin StoneQOL.

OBJECTIVE: We compared postoperative outcomes and quality of life (QoL) between patients who received a nephrostomy tube vs a ureteral stent following percutaneous nephrolithotomy (PCNL) in a prospective, double-blind, randomized manner. MATERIALS AND METHODS: Between September 2015 and March 2016, we randomized 30 patients undergoing PCNL to receive nephrostomy drainage (Group 1: 8F or 10F) or Double-J ureteral stent (Group 2) at conclusion of surgery. Nephrostomy tubes were removed within 48 hours (before discharge) and ureteral stents were removed at least 2 weeks after surgery. Patients' QoL was assessed with the Wisconsin StoneQOL questionnaire preoperatively and then 7 to 10 days and 30 days following surgery. Inclusion criteria included an uncomplicated procedure, normal preoperative renal function, and clinically insignificant residual stone fragments on postoperative imaging. We calculated the preoperative and postoperative QoL score difference between the two groups. We also evaluated perioperative characteristics, inpatient analgesic requirements, length of stay (LOS), and postsurgical complications. OUTCOME: Patient characteristics between Groups 1 and 2 were comparable with similar age (58.3 vs 54.7, p = 0.534), gender ratio, and stone burden (276.6 mm2 vs 259 mm2, p = 0.84) and composition. There was no significant difference between perioperative outcomes, including stone-free rate (93.3% vs 86.7%), operative times (125.7 minutes vs 115 minutes, p = 0.29), estimated blood loss (103.3 mL vs 100.7 mL, p = 0.9), LOS (3.2 days vs 1.9 days, p = 0.1), and complications (2 in each group). Inpatient analgesic requirements were also the same (both 21.1 mg, p = 1.0). Assessment of QoL using the Wisconsin StoneQOL questionnaire showed significant differences between preoperative and postoperative health-related QoL in 18 of the 28-question instrument at 7 to 10 days. Patients in Group 2 had significantly worse QoL change and a multitude of negative responses on the StoneQOL assessment, not only those commonly associated with stent irritation. Eighty percent of participants in Group 2 also attributed their complaints to having a stent placed. Both groups had similar QoL status at 30 days after surgery. CONCLUSION: Despite the literature advocating "tubeless" PCNL with ureteral stent placement at conclusion of surgery, our randomized prospective study shows that QoL is significantly worse with stent placement than with temporary nephrostomy drainage in the immediate aftermath following PCNL, using a validated QoL assessment instrument specific for nephrolithiasis.

Multicenter External Validation and Comparison of Stone Scoring Systems in Predicting Outcomes After Percutaneous Nephrolithotomy.

BACKGROUND AND PURPOSE: Several scoring systems have recently emerged to predict stone-free rate (SFR) and complications after percutaneous nephrolithotomy (PCNL). We aimed to compare the most commonly used scoring systems (Guy's stone score, S.T.O.N.E. nephrolithometry, and CROES nomogram), assess their predictive accuracy for SFR and other postoperative variables, and develop a risk group stratification based on these scoring systems. MATERIALS AND METHODS: We performed a retrospective review of patients who have had a PCNL at four academic institutions between 2006 and 2013. Primary outcome was SFR within 3 weeks of the surgery and secondary outcomes were operative time (OT), complications, and length of stay (LOS). We performed chi-squared, t-test, logistic, linear, and Poisson regressions, as well as receiver operating characteristics curve with area under the curve (AUC) calculation. RESULTS: We identified 586 patients eligible for analysis. Of these, 67.4% were stone free. Guy's, S.T.O.N.E., and CROES score were predictive of SFR on multivariable logistic regression (odds ratio [OR]: 1.398, 95% confidence interval [CI]: 1.056, 1.852, p = 0.019; OR: 1.417, 85% CI: 1.231, 1.631, p < 0.001; OR: 0.993, 95% CI: 0.988, 0.998, p = 0.004) and have similar predictive accuracy with AUCs of 0.629, 0.671, and 0.646, respectively. On multivariable linear regression, only S.T.O.N.E. was an independent predictor of longer OT (ß = 14.556, 95% CI: 12.453, 16.660, p < 0.001). None of the scores were independent predictors of postoperative complications or a longer LOS. Poisson regression allowed for risk group stratification and showed the S.T.O.N.E. score and CROES nomogram to have the most distinct risk groups. CONCLUSIONS: The three evaluated scoring systems have similar predictive accuracy of SFR. S.T.O.N.E. has additional value in predicting OT. Risk group stratification can be used for patient counseling. Further research is needed to identify whether or not any is superior to the others with regard to clinical usefulness and predictive accuracy.

The Expanded Use of Percutaneous Resection for Upper Tract Urothelial Carcinoma: A 30-Year Comprehensive Experience.

INTRODUCTION: The gold standard treatment for upper tract urothelial carcinoma (UTUC) is radical nephroureterectomy (RNU). The role of endoscopic resection is limited to low-risk patients. In this study, we present our 30-year experience in the endoscopic management of UTUC. METHODS: In this retrospective study, we identified 141 patients who underwent percutaneous UTUC resection. Demographic and clinical data were collected, including tumor characteristics, bacillus Calmette-Guérin (BCG) and mitomycin use, tumor recurrence, progression to RNU, and overall survival (OS), and compared in univariate and multivariate analyses. RESULTS: Median follow-up was 66 months. Recurrence occurred in 37% of low-grade patients and 63% of high-grade (HG) patients, with a median time to recurrence of 71.4 vs 36.4 months, respectively. Grade was the only predictor of recurrence (HR 2.12, p = 0.018). The latest time to recurrence occurred after 116 months of surveillance. RNU was avoided by 87% of patients. Age, imperative indications for endoscopy, a history of bladder cancer, and tumor stage and grade were predictors of OS; however, in multivariate analysis, grade and stage lost significance. BCG and mitomycin did not protect against recurrence, progression to RNU, or death over resection alone. CONCLUSION: Percutaneous management of UTUC allows for renal preservation in the majority of patients with resectable disease. Patients with HG tumors are more likely to experience recurrence, but are not at an increased risk of death. Intraluminal BCG and mitomycin continue to have a limited adjuvant role to resection. Recurrence may occur many years following initial resection and therefore prolonged surveillance is advised.

Association of estimated glomerular filtration rate with 24-h urinalysis and stone composition.

The aim of this study is to determine the association of estimated glomerular filtration rate (eGFR) with 24-h urine analysis and stone composition. We performed a retrospective review of 1060 stone formers with 24-h urinalysis, of which 499 had stone composition analysis available. Comparisons of baseline patient characteristics and urinary abnormalities across eGFR groups (<60, 60-89.9, ≥90 mL/min/1.73 m(2)) were performed using Fisher's exact test for categorical data and analysis of variance for continuous variables. Analyses of 24-h urinalysis and stone composition across eGFR groups were performed using linear regression with eGFR groups as a continuous variable to evaluate trends. Of the 1060 patients in the study, 595 (56 %) were males. The mean age was 53.8 years. A total of 38 (4 %), 77 (7 %), and 945 (89 %) patients had eGFR <60, 60-89.9, and ≥90 mL/min/1.73 m(2), respectively. Lower eGFR was associated with older age, lower body-mass index, and female gender (all P < 0.05). Lower eGFR was also associated with lower urinary volume, calcium, citrate, uric acid, sodium, magnesium, phosphorus, sulfate, and creatinine on both univariable and multivariable analyses, adjusted for demographics, comorbidities and medication use (all P < 0.05). The prevalence of hypocitraturia and hypomagnesuria was associated with decreased eGFR, while hypercalciuria, hyperoxaluria, hyperuricosuria and hyperphosphaturia were associated with higher eGFR (all P < 0.05). Stone composition was similar across eGFR groups (all P > 0.05). In conclusion, lower eGFR was associated with lower excretion of urinary elements in a routine 24-h urinalysis, but similar stone composition.

Stenting for malignant ureteral obstruction: Tandem, metal or metal-mesh stents.

Extrinsic malignant compression of the ureter is not uncommon, often refractory to decompression with conventional polymeric ureteral stents, and frequently associated with limited survival. Alternative options for decompression include tandem ureteral stents, metallic stents and metal-mesh stents, though the preferred method remains controversial. We reviewed and updated our outcomes with tandem ureteral stents for malignant ureteral obstruction, and carried out a PubMed search using the terms "malignant ureteral obstruction," "tandem ureteral stents," "ipsilateral ureteral stents," "metal ureteral stent," "resonance stent," "silhouette stent" and "metal mesh stent." A comprehensive review of the literature and summary of outcomes is provided. The majority of studies encountered were retrospective with small sample sizes. The evidence is most robust for metal stents, whereas only limited data exists for tandem or metal-mesh stents. Metal and metal-mesh stents are considerably more expensive than tandem stenting, but the potential for less frequent stent exchanges makes them possibly cost-effective over time. Urinary tract infections have been associated with all stent types. A wide range of failure rates has been published for all types of stents, limiting direct comparison. Metal and metal-mesh stents show a high incidence of stent colic, migration and encrustation, whereas tandem stents appear to produce symptoms equivalent to single stents. Comparison is difficult given the limited evidence and heterogeneity of patients with malignant ureteral obstruction. It is clear that prospective, randomized studies are necessary to effectively scrutinize conventional, tandem, metallic ureteral and metal-mesh stents for their use in malignant ureteral obstruction.

Does Peak Inspiratory Pressure Increase in the Prone Position? An Analysis Related to Body Mass Index.

PURPOSE: Percutaneous nephrolithotomy is commonly performed with the patient prone. There is concern that the prone position, especially in obese patients, negatively affects ventilation due to the restriction of chest compliance and respiratory mechanics. We analyzed the change in airway resistance between supine and prone positioning of patients undergoing percutaneous nephrolithotomy. MATERIALS AND METHODS: We retrospectively reviewed the intraoperative respiratory parameters of 101 patients who underwent prone percutaneous nephrolithotomy. Peak inspiratory pressure was assessed with the patient supine, at several time points after being turned prone and at the end of the case. The change in peak inspiratory pressure with time was calculated. Results were stratified based on body mass index and data were compared using the paired t-test and Spearman ρ. RESULTS: Of 101 patients 50 (50%) were obese (body mass index 30 kg/m(2) or greater). Median body mass index was 25.6 kg/m(2) in the nonobese cohort and 38.3 kg/m(2) in the obese cohort. Average peak inspiratory pressure while supine and prone was 18.0 and 18.5 cm H2O in the nonobese cohort, and 25.5 and 26.6 cm H2O, respectively, in the obese cohort. Obese patients had significantly higher peak inspiratory pressure in the supine and the prone positions relative to nonobese patients (p <0.0001). However, there was no change in peak inspiratory pressure from the supine to the prone position in either cohort. CONCLUSIONS: Obese patients have higher baseline peak inspiratory pressure regardless of position. However, prone positioning does not impact peak inspiratory pressure in either cohort. It remains a safe and viable option.

Does hypertension impact 24-hour urine parameters in patients with nephrolithiasis?

OBJECTIVE: To examine the differences in 24-hour urine parameters and stone composition between patients with and without systemic hypertension (HTN) in a large cohort of stone formers. MATERIALS AND METHODS: We performed a retrospective review over a 10-year period of patients with stone, who had completed a 24-hour urinalysis (Litholink) and for whom demographic information was available, including the presence of HTN. Univariate and multivariate analyses were performed, comparing the 24-hour urinalysis profiles of patients with HTN with that of normotensive patients. RESULTS: Of the 1115 patients eligible for inclusion, 442 patients (40%) had HTN and 673 (60%) did not. Patients with HTN were significantly older, had a higher body mass index, and had a greater number of comorbid conditions than normotensive patients. Univariate analysis revealed significantly lower urine pH, calcium, supersaturation (SS) of calcium oxalate (CaOx) and SS calcium phosphate (all P <.05) in patients with HTN. Multivariate analysis showed significantly lower calcium, citrate, and SS CaOx in patients with HTN (all P <.05). CONCLUSION: Our results demonstrate lower levels of calcium and SS CaOx on univariate and multivariate analysis, as well as lower levels of citrate on multivariate analysis in patients with HTN. These results suggest that lower levels of citrate may contribute to stone formation to a greater degree in patients with HTN than abnormalities in calcium metabolism.

Contemporary assessment of renal stone complexity using cross-sectional imaging.

Recently, several scoring systems have been proposed to predict outcomes of percutaneous nephrolithotomy, objectively and quantitatively assessing kidney calculi complexity using cross-sectional imaging. These scoring systems are promising new tools that can guide surgical decision making, predict surgical outcomes, counsel patients undergoing stone surgery, and improve standardized academic reporting in percutaneous kidney stone surgery. In this article, we review features of each of these systems, their similarities and differences, and their applicability in clinical practice and relevance in academic reporting.

Bladder Necrosis Associated with Placenta Accreta, Embolization, and Repair of Cystotomies.

Bladder necrosis is an unusual and potentially devastating complication of embolization of the hypogastric arterial branches. The rich collateral blood supply makes this an extremely rare event. We present the case of a patient with bladder necrosis following placenta accreta that was treated with total abdominal hysterectomy and uterine artery embolization and cystotomy repairs.

Evaluation and comparison of urolithiasis scoring systems used in percutaneous kidney stone surgery.

PURPOSE: Contemporary predictive tools for percutaneous nephrolithotomy outcomes include the Guy stone score, S.T.O.N.E. nephrolithometry and the CROES nephrolithometric nomogram. We compared each scoring system in the same cohort to determine which was most predictive of surgical outcomes. METHODS: We retrospectively reviewed the records of patients who underwent percutaneous nephrolithotomy between 2009 and 2012 at a total of 3 academic institutions. We calculated the Guy stone score, the S.T.O.N.E. nephrolithometry score and the CROES nephrolithometric nomogram score based on preoperative computerized tomography images. A single observer at each institution reviewed all images and assigned scores. Univariate and multivariate analysis was done to determine the most predictive scoring system. RESULTS: We enrolled 246 patients in study. In stone-free patients vs those with residual stones the mean Guy score was 2.2 vs 2.7, the mean S.T.O.N.E. score was 8.3 vs 9.5 and the mean CROES nomogram score was 222 vs 187 (each p <0.001). Logistic regression revealed that the Guy, S.T.O.N.E. nephrolithometry and CROES nomogram scores were significantly associated with stone-free status (p = 0.02, 0.004 and <0.001, respectively). The Guy and S.T.O.N.E. nephrolithometry scores were associated with estimated blood loss (p <0.0001 and 0.03) and length of stay (p = 0.03 and 0.009, respectively). The CROES nomogram did not predict estimated blood loss or length of stay. CONCLUSIONS: All scoring systems and the stone burden equally predicted stone-free status. The Guy and S.T.O.N.E. nephrolithometry scores were associated with estimated blood loss and length of stay. A single scoring system should be adopted to unify reporting.

Association of serum biochemical metabolic panel with stone composition.

INTRODUCTION: To determine the association of the basic metabolic panel with stone type. METHODS: The present study was a retrospective review of 492 stone formers with both stone composition analysis and basic metabolic panel available. Analysis of a basic metabolic panel across stone types was carried out using Fisher's exact test and analysis of variance. Multinomial logistic regression was used to predict stone type based on a basic metabolic panel. RESULTS: A total of 272 (55%) patients had predominantly calcium oxalate stones, 100 (21%) had uric acid stones, 93 (19%) had calcium phosphate stones, 16 (3%) had mixed stones and 11 (2%) had other types of stones. Uric acid stone formers had the highest serum glucose, blood urea nitrogen and creatinine levels. Calcium oxalate stone formers had the highest serum sodium. No significant differences in mean serum calcium levels across different stone types were identified. The predicted risk of uric acid stone over the other stone types increased with an increase in serum glucose and decreased with an increase in carbon dioxide levels. The predicted risk of calcium oxalate stones increased with an increase in serum sodium and chloride levels. The predicted risk of calcium phosphate and oxalate stones over the other stone types increased with an increase in serum calcium levels. The overall accuracy of the basic metabolic panel alone to predict stone type was 59%. CONCLUSION: A basic metabolic panel alone or in combination with 24-h urinalysis and demographics does not accurately predict stone type. However, it can be used in combination with other variables to predict stone composition.

Differences in 24-h urine composition between nephrolithiasis patients with and without diabetes mellitus.

OBJECTIVES: To examine the differences in 24-h urine composition between nephrolithiasis patients with and without diabetes mellitus (DM) in a large cohort of stone-formers and to examine differences in stone composition between patients with and without DM. PATIENTS AND METHODS: A retrospective review of 1117 patients with nephrolithiasis and a 24-h urine analysis was completed. Univariable analysis of 24-h urine profiles and multivariable linear regression models were performed, comparing patients with and without DM. A subanalysis of patients with stone analysis data available was performed, comparing the stone composition of patients with and without DM. RESULTS: Of the 1117 patients who comprised the study population, 181 (16%) had DM and 936 (84%) did not have DM at the time of urine analysis. Univariable analysis showed significantly higher total urine volume, citrate, uric acid (UA), sodium, potassium, sulphate, oxalate, chloride, and supersaturation (SS) of UA in individuals with DM (all P < 0.05). However, patients with DM had significantly lower SS of calcium phosphate and pH (all P < 0.05). Multivariable analysis showed that patients with DM had significantly lower urinary pH and SS of calcium phosphate, but significantly greater citrate, UA, sulphate, oxalate, chloride, SSUA, SS of calcium oxalate, and volume than patients without DM (all P < 0.05). Patients with DM had a significantly greater proportion of UA in their stones than patients without DM (50.2% vs 13.5%, P < 0.001). CONCLUSIONS: DM was associated with multiple differences on 24-h urine analysis compared with those without DM, including significantly higher UA and oxalate, and lower pH. Control of urinary UA and pH, as well as limiting intake of dietary oxalate may reduce stone formation in patients with DM.

Percutaneous nephrolithotomy during uninterrupted aspirin therapy in high-cardiovascular risk patients: preliminary report.

OBJECTIVE: To determine the feasibility and safety of performing percutaneous nephrolithotomy (PCNL) in high-cardiovascular risk patients remaining on aspirin therapy. METHODS: We retrospectively reviewed all PCNLs performed by 3 fellowship-trained endourologists at a single institution between July 2012 and January 2014. All patients remaining on aspirin for imperative indications through the day of surgery were evaluated for surgical outcomes and thromboembolic events. RESULTS: Of 281 PCNL procedures performed during the study period, 16 (5.7%) were performed in 14 patients taking aspirin, uninterrupted, through surgery. Mean surgery time was 66 minutes, mean estimated blood loss was 161 mL, and mean length of hospital stay was 2.8 days. All patients were stone free. There were no intraoperative complications. A total of 5 patients experienced a postoperative complication (n = 4, Clavien grade II; n = 1, Clavien grade IIIa). No patient experienced a perioperative thromboembolic or cardiac event. Three patients required a blood transfusion postoperatively, and none experienced delayed renal bleeding. CONCLUSION: PCNL can be performed safely and effectively in high-cardiovascular risk patients continuing aspirin perioperatively. Compared with the potential sequelae of a thromboembolic or cardiac event, PCNL is associated with an acceptably low transfusion rate, and should be considered a viable treatment option for large renal stones in this population.