Jessica A. Mandeville

Changing composition of renal calculi in patients with musculoskeletal anomalies.

BACKGROUND AND PURPOSE Calculi from patients with musculoskeletal (MS) anomalies who are largely immobile and prone to urinary infections have been traditionally composed primarily of struvite and carbonate apatite. Because of substantial improvements in the care of these patients in recent decades, stone etiology may have shifted from infectious to metabolic. We assessed the composition of renal calculi and metabolic characteristics in a contemporary cohort of patients with MS anomalies who underwent percutaneous nephrolithotomy (PCNL). PATIENTS AND METHODS Retrospective analysis of patients who underwent PCNL between April 1999 and June 2009 and had follow-up 24-hour urine studies was performed. Patients with MS anomalies included spinal cord injury, myelomeningocele, muscular dystrophy, multiple sclerosis, cerebral palsy, or other clinical syndromes causing kyphoscoliosis and contractures. RESULTS Our cohort included 33 patients with MS anomalies and 334 consecutive patients as a control group who underwent PCNL and had metabolic workup. Stones were infectious in etiology in 18.4% and 6.2% in MS and control groups, respectively. Thus, most patients harbored stones of metabolic origin. Metabolic stones in the MS group were composed of 52.7% hydroxyapatite, 10.5% calcium oxalate, 7.9% brushite, 2.6% uric acid, 0% cystine, and 7.9% other. Metabolic stones in the control group were 50.5% calcium oxalate, 16.4% hydroxyapatite, 11.5% brushite, 10.8% uric acid, 4.3% cystine, and 0.3% other. Mean 24-hour urine values for patients with metabolic stones in MS/control groups were volume 2.18/1.87 L/d, pH 6.78/6.05, calcium to creatinine ratio 220/151 mg/g, and oxalate 44.8/39.5 mg/d. CONCLUSIONS Although patients with MS anomalies are traditionally thought to harbor infection-related calculi, most will be found to have calculi of metabolic etiology. The incidence of calcium phosphate stones is high in this group of patients, perhaps reflecting their high urinary pH.

The Utility of Noncontrast Computed Tomography in the Prompt Diagnosis of Postoperative Complications After Percutaneous Nephrolithotomy

INTRODUCTION Noncontrast computed tomography (CT) is commonly utilized after percutaneous nephrolithotomy (PNL) to assess stone-free (SF) status. In addition to assessing SF status, CT is useful in the recognition of complications after PNL. We characterized complications demonstrated by postoperative CT scan and compared hospital re-admission rates based on whether or not CT was performed. METHODS We retrospectively reviewed records of 1032 consecutive patients from April 1999 to June 2010. Patients were divided into two cohorts based on whether they had a CT within 24 hours of PNL. Demographic data, CT findings, and need for re-admission for complication management were assessed. RESULTS Nine hundred fifty-seven patients (92.7%) underwent post-PNL CT. CT-diagnosed complications were perinephric hematoma in 41 (4.3%; 2 requiring embolization and 9 necessitating transfusion), pleural effusion in 25 (2.6%; 10 requiring intervention), colon perforation in 2 (0.2%), and splenic injury in 2 (0.2%). Of patients with postoperative complications, 33% required intervention. Among patients with a CT, 6 (0.6%) were readmitted despite negative postoperative CT (four perinephric hematomas, one calyceal-pleural fistula, and one pseudoaneurysm). The sensitivity of CT for diagnosing complications was 92.7%. Seventy-five patients (7.3%) did not undergo CT post-PNL. Of these, four (5.33%) were readmitted: three for perinephric hematomas and one for ureteral clot obstruction. Patients undergoing post-PNL CT were less likely to be readmitted because of missed complications (p=0.02). CONCLUSIONS Serious post-PNL complications are uncommon, but their prompt diagnosis and treatment is imperative. In addition to identifying residual stones, CT is useful in diagnosing postoperative complications. Postoperative CT could potentially be considered for all patients undergoing PNL, particularly in complex cases such as patients with anatomical abnormalities (renal anatomic abnormality or retrorenal colon), patients requiring upper pole access (risk of thoracic, hepatic, and splenic complications), and patients requiring multisite access (higher risk of perinephric hematoma or need for transfusion).

Lithotripter Outcomes in a Community Practice Setting: Comparison of an Electromagnetic and an Electrohydraulic Lithotripter

PURPOSE We assessed patient outcomes using 2 widely different contemporary lithotripters. MATERIALS AND METHODS We performed a consecutive case series study of 355 patients in a large private practice group using a Modulith® SLX electromagnetic lithotripter in 200 patients and a LithoGold LG-380 electrohydraulic lithotripter (TRT, Woodstock, Georgia) in 155. Patients were followed at approximately 2 weeks. All preoperative and postoperative films were reviewed blindly by a dedicated genitourinary radiologist. The stone-free rate was defined as no residual fragments remaining after a single session of shock wave lithotripsy without an ancillary procedure. RESULTS Patients with multiple stones were excluded from analysis, leaving 76 and 142 treated with electrohydraulic and electromagnetic lithotripsy, respectively. The stone-free rate was similar for the electrohydraulic and electromagnetic lithotripters (29 of 76 patients or 38.2% and 69 of 142 or 48.6%, p = 0.15) with no difference in the stone-free outcome for renal stones (20 of 45 or 44.4% and 33 of 66 or 50%, p = 0.70) or ureteral stones (9 of 31 or 29% and 36 of 76 or 47.4%, respectively, p = 0.08). The percent of stones that did not break was similar for the electrohydraulic and electromagnetic devices (10 of 76 patients or 13.2% and 23 of 142 or 16.2%) and ureteroscopy was the most common ancillary procedure (18 of 22 or 81.8% and 30 of 40 or 75%, respectively). The overall mean number of procedures performed in patients in the 2 groups was similar (1.7 and 1.5, respectively). CONCLUSIONS We present lithotripsy outcomes in the setting of a suburban urology practice. Stone-free rates were modest using shock wave lithotripsy alone but access to ureteroscopy provided satisfactory outcomes overall. Although the acoustic characteristics of the electrohydraulic and electromagnetic lithotripters differ substantially, outcomes with these 2 machines were similar.

Imaging Evaluation in the Patient With Renal Stone Disease

Numerous imaging modalities are available for the evaluation of patients with renal stone disease. The study of choice is dependent on the clinical scenario and the indication for imaging. Additional factors such as patient age and pregnancy status will influence the radiographic study that is chosen. Currently available technologies for the evaluation of urolithiasis include plain abdominal radiography, ultrasound, intravenous pyelogram, computed tomography, and magnetic resonance imaging. This article reviews the indications, advantages, and disadvantages of each study in the evaluation of patients with known or suspected stone disease.

An update on holmium laser enucleation of the prostate and why it has stood the test of time

Purpose of review Holmium laser enucleation of the prostate is an endoscopic alternative for the treatment of symptomatic benign prostatic hyperplasia for men with prostates of any size. Holmium laser enucleation of the prostate is superior to other modalities for the treatment of benign prostatic hyperplasia. We present the most current literature on this procedure. Recent findings In the 18-month span of this review, there have been a number of articles published on holmium laser enucleation of the prostate. These studies assessed the safety, efficacy, and durability of this procedure. Among these is the largest study to date providing supporting evidence to the long-term efficacy and safety of holmium laser enucleation of the prostate. Other studies provide compelling evidence to suggest that holmium laser enucleation of the prostate can be used in prostates of any size and can provide long-term durable outcomes. Summary Holmium laser enucleation of the prostate represents an effective, well tolerated, and durable procedure to relieve bladder outlet obstruction due to benign prostatic hyperplasia. Holmium laser enucleation of the prostate is a minimally invasive approach which accomplishes complete adenoma removal and, as such, provides unique advantages over other surgical treatments for men with benign prostatic hyperplasia.

Current Understanding of the Role of Randall’s Plaque

The mechanisms by which urinary calculi develop in humans are not entirely understood. In the 1930s, Randall described white plaques on the papillae of cadaveric kidneys from patients with calculi and postulated that this was the site of stone formation in all stone formers. His theory was not well received and for many years was abandoned. It is now known that in certain subsets of stone formers (idiopathic calcium oxalate stone formers), stone formation does occur by overgrowth on Randall’s plaque. However, many other types of stone formers do not demonstrate evidence of classic Randall’s plaque and must therefore possess a different mechanism for stone formation. Careful endoscopic assessment and renal tissue biopsies from unique stone-forming patients (i.e., those with cystinuria, primary hyperparathyroidism, renal tubular acidosis, and primary hyperoxaluria) has revealed evidence of crystalline plugging within dilated ducts of Bellini with associated inflammation and cell injury. These findings are not identified in idiopathic calcium oxalate stone formers and lead one to believe that alternate pathways to the development of nephrolithiasis must be at play. In this chapter we review the composition and anatomic location of Randall’s plaque as well as describe the stone-plaque interface and mechanism of stone overgrowth. Additionally, we review the specific endoscopic and histologic abnormalities in stone-forming patients with cystinuria, brushite stone disease, gastric bypass, ileostomy, primary hyperparathyroidism, renal tubular acidosis, and primary hyperoxaluria and propose potential mechanisms for stone formation.

MP02-08 HOLEP IN PATIENTS WITH LOW RISK PROSTATE CANCER IS SAFE AND EFFECTIVE

INTRODUCTION AND OBJECTIVES: The optimal management option for BPH/LUTS for prostates >80g is unclear. Theoretical advantages of GLEP include improved hemostasis due to the absorption spectrum of 532nm laser, better tissue handling due to the sidefiring laser fiber, better visualization of the prostate capsule, and more versatility with concomitant vaporization. We study the safety and feasibility of en-bloc GLEP with prostate morcellation using a side-firing laser as a new technique for definitive management of symptomatic LUTS in patients with prostates >80g. METHODS: We performed a retrospective analysis of 82 consecutive patients who underwent GLEP from 9/2014 to 8/2016. Primary outcomes were AUA symptom score, maximum flow rate, and post-void residual volume. Secondary outcomes were quality of life score, IIEF-5 score, and PSA. Technique: Using 26 Fr Wolf resectoscope and side-firing 2090 GreenLight laser fiber, we incise the apical mucosa, separating the prostate from the external sphincter. Using the laser energy and blunt dissection, prostate lobes are enucleated on either side of the verumontanum. Dissection is carried out circumferentially until the bladder neck is reached. Hemostasis is achieved with laser coagulation. Once the enucleated adenoma is pushed into the bladder, morcellation is completed using the Wolf Piranha morcellator. RESULTS: Mean age was 71 years, with 47.6% of patients on anticoagulation and/or antiplatelet therapy. Mean procedure time was 140 min 55. The mean preoperative prostate size was 145ml 86.46, with a mean size morcellated volume of 66mL 54. 75% of patients were discharged home on postoperative day (POD) 1 and 75% of patients had catheters removed by POD2. Primary and secondary outcomes can be found in Table 1, with statistically significant improvement in all parameters (p<0.05) except IIEF-5, which demonstrated no change. Complication rates included 1.2% blood transfusion, 6.1% clot retention, 4.9% urinary tract infection, and 13.4% stress urinary incontinence. The majority of patients regained continence at later follow-up. There was no incidence of urethral stricture, capsular perforation, bladder or ureteral injury. CONCLUSIONS: In experienced hands, GLEP is a safe and feasible option for management of large prostates.