Differences in quantitative urine composition in stone-forming versus unaffected mate kidneys.

Objectives: Many patients present with bilateral stones. There is a unique group of patients, however, that presents with stones exclusively on one side. We hypothesize that in such situations, 24-hour urine collections may not reveal specific defects on the affected stone-bearing kidney.

Synthesis and solid-state NMR structural characterization of 13C-labeled graphite oxide.

The detailed chemical structure of graphite oxide (GO), a layered material prepared from graphite almost 150 years ago and a precursor to chemically modified graphenes, has not been previously resolved because of the pseudo-random chemical functionalization of each layer, as well as variations in exact composition. Carbon-13 (13C) solid-state nuclear magnetic resonance (SSNMR) spectra of GO for natural abundance 13C have poor signal-to-noise ratios. Approximately 100% 13C-labeled graphite was made and converted to 13C-labeled GO, and 13C SSNMR was used to reveal details of the chemical bonding network, including the chemical groups and their connections.

Graphene-based ultracapacitors.

The surface area of a single graphene sheet is 2630 m(2)/g, substantially higher than values derived from BET surface area measurements of activated carbons used in current electrochemical double layer capacitors. Our group has pioneered a new carbon material that we call chemically modified graphene (CMG). CMG materials are made from 1-atom thick sheets of carbon, functionalized as needed, and here we demonstrate in an ultracapacitor cell their performance.

Percutaneous management of stones in transplanted kidneys.

Objectives: Stone disease is a rare complication after renal transplantation, and the management of these stones can be difficult. In many cases, the best modality to treat stones in transplanted kidneys/ureters is with a percutaneous approach. The goal of this study was to review our series of percutaneous nephrolithotomy (PNL) to evaluate the success rates and present the key technical points to achieve a successful outcome.

Association between Randall's plaque and calcifying nanoparticles.

Objectives: Randall initially described calcified subepithelial papillary plaques, which he hypothesized as nidi for urinary calculi. The discovery of calcifying nanoparticles (CNP), also referred to as nanobacteria, in calcified soft tissues has raised another hypothesis about their possible involvement in urinary stone formation. This research is the first attempt to investigate the potential association of these two hypotheses.

Endoscopic management of obstructive complications in ureterosigmoidostomy.

Objectives: Although rarely used today for supravesical urinary diversion, ureterosigmoidostomy remains useful in patients with bladder exstrophy. However, management of ureteral stricture and ureteral urolithiasis is challenging because of the lack of anatomic landmarks.

Methods: We reviewed our prospectively collected database from 1994 to 2006 for all patients requiring surgical treatment for obstructive complications associated with ureterosigmoidostomy.

Laparoscopic nephrectomy, ex vivo partial nephrectomy followed by allograft renal transplantation.

A shortage of available kidneys exists. Forty percent of patients with end stage renal disease wait more than 2 years for renal transplant. We report a case of a 22-year-old man who underwent laparoscopic radical nephrectomy for a 2-cm central renal mass.

Oral calcium supplementation associated with decreased likelihood of nephrolithiasis prior to surgery for hyperparathyroidism.

We aimed to assess the impact of oral calcium supplementation (OCS) on the prevalence of nephrolithiasis among a cohort of patients undergoing surgery for primary hyperparathyroidism (PHPT). There were 339 patients undergoing surgery for PHPT with detailed past medical history data that were analyzed. 73 patients (22%) had a history of nephrolithiasis prior to parathyroid surgery.

Long-term outcomes and late complications of laparoscopic nephrectomy with renal autotransplantation.

Purpose: We report long-term outcomes and late complications after laparoscopic nephrectomy with autotransplantation.

Materials And Methods: We retrospectively reviewed clinical data on all patients who underwent laparoscopic nephrectomy with autotransplantation between July 2000 and March 2007. Late complications, ie greater than 6 months, that required surgical intervention were analyzed.

Urinary citrate levels do not correlate with urinary pH in patients with urinary stone formation.

Objectives: Urinary excretion of citrate is dependent on glomerular filtration, tubular reabsorption, and excretion. Acid base status is thought to play a significant role in urinary citrate excretion. It has been assumed that increased urinary citrate will increase urinary pH.

Effect of body position on renal parenchyma perfusion as measured by nuclear scintigraphy.

Objectives: To compare differential renal perfusion in various body positions in healthy volunteers, to help postulate factors responsible for recurrent unilateral stone formation.

Methods: Ten volunteers with normal renal function and no history of urinary disease were evaluated with diuretic renography using mercaptoacetyl-triglycine. Scintigraphy was performed 1 week apart in each of three typical sleep positions (supine, left lateral decubitus, right lateral decubitus), and renal perfusion was measured.

Minimizing and managing bleeding after percutaneous nephrolithotomy.

Purpose Of Review: As urologists will continue to rely on percutaneous nephrolithotomy, a clear understanding of its associated bleeding risks and management is mandatory.

Recent Findings: Despite advances in lithotripsy technology, bleeding continues to be a cause of patient morbidity in percutaneous nephrolithotomy. Although most patients can be managed conservatively, a subset of patients will require endovascular embolization for vascular control.

Traditional Foley drainage systems--do they drain the bladder?

Purpose: Foley catheters are assumed to drain the bladder to completion. Drainage characteristics of Foley catheter systems are poorly understood. To investigate unrecognized retained urine with Foley catheter drainage systems, bladder volumes of hospitalized patients were measured with bladder scan ultrasound volumetrics.

Laparoscopic versus open cytoreductive nephrectomy in advanced renal-cell carcinoma.

Background And Purpose: There is growing evidence of the benefit of cytoreductive nephrectomy prior to immunotherapy in patients with advanced renal-cell carcinoma (RCC). We compared the outcomes of patients with metastatic RCC undergoing laparoscopic and open cytoreductive nephrectomy prior to systemic therapy.

Patients And Methods: We retrospectively analyzed 27 patients undergoing cytoreductive nephrectomy for metastatic RCC between 2000 and 2004, 16 laparoscopically and 11 by an open approach.

The effect of kidney morcellation on operative time, incision complications, and postoperative analgesia after laparoscopic nephrectomy.

Introduction: Compare the outcomes between kidney morcellation and two types of open specimen extraction incisions, several covariates need to be taken into consideration that have not yet been studied.

Materials And Methods: We retrospectively reviewed 153 consecutive patients who underwent laparoscopic nephrectomy at our institution, 107 who underwent specimen morcellation and 46 with intact specimen removal, either those with connected port sites with a muscle-cutting incision and those with a remote, muscle-splitting incision. Operative time, postoperative analgesia requirements, and incisional complications were evaluated using univariate and multivariate analysis, comparing variables such as patient age, gender, body mass index (BMI), laterality, benign versus cancerous renal conditions, estimated blood loss, specimen weight, overall complications, and length of stay.

Novel everting urologic access sheath: potential advantages of decreased cellular advancement.

Background And Purpose: Axial forces are imposed on the urothelium during advancement of instruments across the urinary tract, potentially transferring cellular debris, bacteria, or urothelial carcinoma from one anatomic location to another. A prototype access sheath (Cystoglide; Percutaneous Systems, Mountain View, CA) was created that everts and radially dilates but does not provide axial forces during deployment that can be used in a variety of anatomic systems. We created a urinary-tract model to evaluate the in-vitro advancement of cells to compare this technology with using instruments alone.

Novel everting urologic access sheath: decreased axial forces during insertion.

Background: Advancement of urologic instruments through the genitourinary tract is associated with significant axial forces that likely contribute to patient discomfort, even after injection of a local anesthetic, and may lead to mucosal trauma, postprocedural dysuria and hematuria, and increased susceptibility to infection and strictures. Placing an everting urethral sheath prior to instrumentation may decrease these problems.

Materials And Methods: Two 7-cm-long, 5-mm diameter urethral luminal models were created, one with and one without an artificial stricture.

Risk of injury to adjacent organs with lower-pole fluoroscopically guided percutaneous nephrostomy: evaluation with prone, supine, and multiplanar reformatted CT.

Purpose: To assess the risk of injury to organs near the kidney during lower-pole fluoroscopically guided percutaneous nephrostomy by evaluation of prone, supine, and multiplanar reformatted computed tomography (CT).

Materials And Methods: Eighty-three patients who underwent prone and supine CT examinations were identified retrospectively. The expected path of nephrostomy tube placement to the lower-pole calyx was simulated on prone and supine axial images and multiplanar CT reformations.

Laparoscopic appreciation of the adrenal artery: fact or fiction?

Background: It is well accepted that identification and control of the adrenal vein is a critical step in laparoscopic adrenalectomy. The surgical and anatomic literature propagates the notion of a dominant or multiple dominant adrenal arteries that should likewise be controlled during surgical extirpation.

Materials And Methods: We assessed the frequency of adrenal-artery identification and the need for formal ligation in an extensive series of laparoscopic adrenalectomies.

More than 500 consecutive laparoscopic donor nephrectomies without conversion or repeated surgery.

Hypothesis: Concern exists as to the safety of laparoscopic donor nephrectomy (LDN) compared with open donor nephrectomy. Reported complications of LDN include emergent conversion to an open procedure, repeated surgery for postoperative bleeding, and even death. We hypothesize that LDNs can be performed safely, with a complication rate comparable with that of open donor nephrectomies.

Failed percutaneous balloon dilation for renal access: incidence and risk factors.

Objectives: To present our experience using balloon dilation and discuss secondary techniques to establish a percutaneous tract when balloon dilation fails. Balloon dilation is a safe and effective method to achieve percutaneous renal access, but it is not uniformly successful. Also, the failure rate and risk factors have not been well documented.

Laparoscopic management of peripelvic renal cysts: University of California, San Francisco, experience and review of literature.

Objectives: To report our experience and review published reports on the laparoscopic management of peripelvic renal cysts. Peripelvic renal cysts represent a unique subset of renal cysts, as they are rare, commonly symptomatic, and more difficult to treat than simple peripheral renal cysts. Minimally invasive methods for the treatment of peripelvic renal cysts, including laparoscopic decortication, have recently become more common.

Bursting strength with various methods of renal artery ligation and potential mechanisms of failure.

Background And Purpose: Vascular control is crucial during laparoscopic ligation of the renal vessels. Intracorporeal suture ligation has been replaced by easier methods, such as specialized clip appliers and automatic stapling devices; nevertheless, the optimal application and margin of safety of such devices have yet to be determined. We sought to address this question by measuring the bursting strength of arteries ligated with several standard devices.