Internet-Based Patient Survey on Urolithiasis Treatment and Patient Satisfaction.

PURPOSE: We created an Internet-based survey of patients treated for urolithiasis to evaluate for trends in treatment, outcome, and patient satisfaction and to establish internet surveys as a feasible medium for future research of patient urolithiasis treatment experiences. MATERIALS AND METHODS: We used the website "kidneystoners.org" to disseminate the online survey, which queried respondents on treatment type, outcome, and satisfaction. Patient satisfaction was correlated with treatment type and outcome. Chi-square and analysis of variance tests were used to compare responses between treatment types. RESULTS: Four hundred forty-three respondents completed the survey. The majority (46%) were treated ureteroscopically, followed by extracorporeal shock wave lithotripsy (SWL, 25%) and percutaneous nephrolithotomy (7%). Other treatments included spontaneous passage (13%), medical expulsive therapy (7%), and home remedies (2%). Sixty-four percent of respondents deemed their treatment "successful," while 36% reported their treatment as either "partially successful" or "unsuccessful." Unsuccessful treatment was more likely for SWL (17%) and home remedies (14%) (p=0.002). Most respondents (52%) reported being either satisfied or very satisfied with their treatment choice. Satisfaction did not vary significantly by treatment type, but was significantly associated with treatment success (mean satisfaction 3.8/5 for "successful" vs 1.9/5 for "unsuccessful" treatment; p<0.0001). CONCLUSION: Use of the Internet allows rapid gathering of patient information from a large geographic distribution. Our survey is consistent with previous studies in demonstrating an increased use of ureteroscopy to treat both renal and ureteral calculi. In general, patients are satisfied with treatment outcomes despite a large percentage of people reporting needing to have secondary procedures.

Patient experiences and preferences with ureteral stent removal.

PURPOSE: Ureteral stent removal is a source of patient morbidity. We surveyed 599 patients to evaluate their experiences and identify the preferred method of stent removal. MATERIALS AND METHODS: Visitors to a kidney stone website were invited to participate. Respondents were asked how their ureteral stent was removed? Pain during and after the procedure, patient experiences, and preferences regarding stent removal were queried. Chi-square and ANOVA tests were used to identify significant differences among removal methods. RESULTS: Five hundred seventy-one respondents were included in the study. The majority of stents (44%) were removed by office cystoscopy while 39% had their stents removed by string. Mean pain during stent removal was 4.8 out of 10 with 57% reporting moderate-to-severe pain levels of 4 or more. Removal by office cystoscopy resulted in the highest experienced pain (5.3). Thirty-two percent reported delayed severe pain after stent removal, including 9% who returned for emergency care. Removal by string resulted in more emergency room visits when compared to cystoscopy. Willingness to undergo the same removal technique was lowest for those who underwent office cystoscopy and highest for operating room cystoscopy. Being informed of why a stent was placed and the removal process was of high priority for respondents. CONCLUSIONS: The majority of patients report moderate-to-severe pain with stent removal and a third report delayed significant pain after stent removal. Variations exist in the patient experience with stent removal based on the method used. More research is needed to identify effective ways to prevent or manage stent-removal-related adverse events.

Urolithiasis risk factors in the bariatric population undergoing gastric bypass surgery.

BACKGROUND: Previous studies have suggested an increased risk of forming symptomatic urolithiasis after Roux-en-Y gastric bypass (RYGB) attributed to the development of hyperoxaluria. The objective of our investigation was to evaluate changes in the urine milieu after RYGB that might explain the increased risk of urolithiasis. METHODS: Patients underwent serum and urine chemistry tests 1 week before and 6 months after RYGB at a university hospital. The postoperative urolithiasis risk factors were compared with the preoperative values. Statistical analysis was performed using paired t tests. Significant changes were identified as P ≤ .05. RESULTS: A total of 38 patients (7 men and 31 women) submitted samples both before and after RYGB. The mean patient weight had decreased from 131 kg to 92 kg. The mean serum creatinine decreased from .83 to .72 mg/dL (P = .0004). Urinary changes known to increase the risk of urolithiasis include a decrease in volume (2-1.5 L/d, P = .03), an increase in calcium (139-182 mg/d, P = .04), and an increase in oxalate (38-48 mg/d, P < .001). The urinary supersaturation indexes for calcium oxalate (4.9-10.5, P < .001) increased. CONCLUSION: Our results confirm that patients undergoing RYGB develop changes in the urinary milieu predisposing them to forming urinary stones. Urolithiasis risk is multifactorial and is related to more than just hyperoxaluria. A patient's long-term risk of developing stones and the effect on renal function is unknown. Preoperative counseling of patients regarding their risk of forming stones and dietary counseling to minimize their risk of developing stones postoperatively is warranted.

Changes in renal function following Roux-en-Y gastric bypass: a prospective study.

BACKGROUND: Studies of the impact of Roux-en-Y gastric bypass (RYGB) on renal function have shown mixed results. We constructed this prospective repeated-measures controlled study to characterize this response and identify the best method of gauging renal function in this setting. METHODS: Clinical data, serum creatinine (SC), and 24-h urine were collected 1 week before and 6 months following RYGB. Glomerular filtration rate (GFR) was calculated utilizing the Modification of Diet in Renal Disease formula. Creatinine clearance (CCL) was measured as a 24-h collection (24 CCL) and calculated by the Cockcroft-Gault (CG) formula. RESULTS: The study population of 37 patients (81% women) had a mean age of 47 ± 11 years, had mean BMI of 47.6 ± 6.3 kg/m(2), and achieved a mean % excess weight loss (EWL) of 60.9 ± 17.1%. SC decreased from 0.83 ± 0.21 mg/dl to 0.72 ± 0.16 mg/dl (p < 0.001) and mean GFR improved from 91.6 ± 29.7 ml/min/1.73 m(2) to 104.9 ± 23.5 ml/min/1.73 m(2) (p < 0.01). Preoperatively, CG significantly overestimated CCL when compared with 24 CCL (197.1 ± 88.2 ml/min vs. 136.5 ± 53.0 ml/min, p < 0.001). In all patients, improvement in 24 CCL correlated with EWL (r = 0.32) and %EWL (r = 0.16), and significantly correlated with decrease in BMI (r = 0.51, p < 0.005). In hypertensive patients, improvement in 24 CCL significantly correlated with EWL (r = 0.43, p < 0.05), %EWL (r = 0.40, p < 0.05), and decrease in BMI (r = 0.60, p < 0.001) and was negatively correlated with age (r = -0.45, p < 0.05). CONCLUSIONS: This study demonstrates that renal function improves following RYGB and is best identified by change in GFR. Improvement in 24 CCL is correlated with the EWL success of the patient, especially hypertensive patients.

Rapid onset renal deterioration in an adult with silent ureteropelvic junction obstruction.

We report a case of a rapid renal deterioration due to ureteropelvic junction obstruction (UPJO) in an asymptomatic woman with prior normal diuretic renography. This case illustrates "silent" renal obstruction and the inability of diuretic renography in detecting significant renal obstruction. This case may favor close surveillance of any adult patient with potential UPJO, especially those with underlying renal disease or solitary kidney.

Use of a surgical helmet system to minimize splash injury during percutaneous renal surgery in high-risk patients.

The transmission risk to surgeons performing percutaneous renal surgery on patients who are infected with human immunodeficiency virus/acquired immunodeficiency syndrome, hepatitis B, or hepatitis C is unknown. A recent study found 55% of surgeons' masks contain evidence of blood splash contamination after percutaneous nephrolithotomy. While the risk of infectious disease transmission to the surgeon after mucocutaneous exposure is unknown, the incapacitating disease these pathogens cause can have a devastating and permanent effect on a surgeon's career. We describe our use of a surgical helmet system when performing percutaneous renal surgery on high-risk patients to minimize risk of splash injury and transmission of blood-borne pathogens.

Evaluation of the impact and need for use of a safety guidewire during ureteroscopy.

BACKGROUND AND PURPOSE: The routine use of a "safety" guidewire adjacent to the ureteroscope during upper tract endoscopy is advocated in surgical texts and by many endourologists. Our experience has led us to theorize that a safety guidewire complicates ureteroscopy by providing resistance to introduction of the endoscope and by creating an obstruction to ureteroscopic instrumentation. To examine our theory, we developed a porcine animal model to evaluate the impact of the presence of a safety guidewire and reviewed our clinical experience, which routinely does not use a safety guidewire during ureteroscopy. PATIENTS AND METHODS: An ex vivo model was created using the excised urinary tract of freshly slaughtered pigs. The forces needed to advance both a semirigid and flexible ureteroscope in the ureter were measured with and without the presence of a 0.035-inch safety guidewire. The clinical records of all patients undergoing ureteroscopy over a 4-year period were reviewed. RESULTS: On average, an additional 12 and 20 g of force were needed to introduce the semirigid and flexible ureteroscope when a guidewire was present. For the chosen study period, 361 patients underwent ureteroscopic procedures without the placement of a safety guidewire. No patient experienced an intraoperative complication related to the absence of a safety wire. CONCLUSIONS: The presence of a safety guidewire adjacent to the endoscope inhibits passage of the ureteroscope in an in vitro animal model. Technologic advancements in ureteroscope design and use of the holmium laser lithotrite minimize ureteral trauma and obviate the need for routine use of a safety wire during ureteroscopy.

Current laparoscopy training in urology: a comparison of fellowships governed by the Society of Urologic Oncology and the Endourological Society.

BACKGROUND AND PURPOSE: Laparoscopic surgery is now an integral technique in the practice of urology, particularly in the management of certain urologic malignancies. Advanced laparoscopy training in urology is primarily reserved for those pursuing fellowship training and is offered both by traditional endourology fellowships and increasingly in urologic oncology fellowships. The purpose of our study was to evaluate and compare current laparoscopy training at the fellowship level. MATERIALS AND METHODS: A 17-item questionnaire was developed with support from both the Endourological Society (EUS) and Society of Urologic Oncology (SUO). Surveys were sent to program directors of fellowships recognized by the EUS and SUO. Directors were surveyed on the laparoscopic case volume, degree of oncology training, and career choice of their graduates. Data were analyzed with Wilcoxon rank-sum and Student t tests. RESULTS: Our survey had an overall response rate of 60%. Fellows performed more than 100 laparoscopies during their training period in 57% of EUS and 25% of SUO fellowship programs. Similar trends are demonstrated when analyzing robotic procedures, with 73% of EUS fellows performing more than 50 procedures compared with 43% of SUO fellows. The majority (59%) of EUS programs provide oncologic training. Between 44% and 100% of graduates from EUS and SUO fellowships obtain academic positions. The majority of SUO directors (63%) believe that fellowship training in laparoscopy should be provided in fellowships governed solely by the SUO, while 41% of EUS directors believe this training should be governed solely by the EUS. CONCLUSIONS: Endourology fellowships currently provide a greater exposure to laparoscopy and robotics than SUO fellowships. The percentage of fellows seeking academic positions is similar for EUS and SUO fellowship programs and has remained stable for several years. Directors of fellowship programs that offer advanced laparoscopic training have divergent views as to which administrative body should govern its future.

Wireless teleradiology for renal colic and renal trauma.

BACKGROUND PURPOSE: Image transmission is an integral part of telemedicine, allowing evaluation of patients at remote sites. We developed a simple method of wireless transmission of digital images to a hand-held computer (PDA) and evaluated its feasibility and diagnostic accuracy in patients with acute renal colic or renal trauma. MATERIALS AND METHODS: The CT images from 11 patients with suspected renal colic and one patient with renal trauma were transmitted using a cellular telephone with a wireless modem link to a PDA (Sony Clie 615C). A diagnostic interpretation was recorded for the presence/absence of an upper-tract stone, stone location, estimated stone size, and signs of upper-tract obstruction. Radiologic staging of trauma was provided in the patient with a renal injury. Comparison was made with the final dictated report of a staff radiologist. RESULTS: Ten CT sets of patients with renal colic were used for comparison, the remaining one being excluded because of ambiguity in the final radiology report. An average of 5.9+/-1.6 images, average size 32.2+/-5.2 kb (range 21-42 kb) for each patient were sent at an average speed of 1 kb/sec. Interpretation correctly identified stone presence in 80%, hydronephrosis in 100%, and perinephric stranding in 80% and stone size within 1+/-1 mm. A stage-3 renal trauma was correctly identified and staged. CONCLUSION: Wireless teleradiology to PDA units provides image quality sufficient for diagnostic interpretation. Anticipated improvements in wireless transmission and PDA screen image resolution will enhance the speed, quality, and quantity of images transmitted. Wireless teleradiology may facilitate convenient rapid evaluation of patients at remote sites.

The evolution and progress of ureteroscopy.

Technology and refinements in urology have prospered with the bonding of engineers and surgeons. The introduction of fiberoptics and the development of the ureteroscope opened the doors to the field of ureteroscopy. Advances in rigid and flexible ureteroscopy with irrigating and working channels have expanded the capability of the urologist to diagnose and treat most abnormalities of the upper tracts in adult and pediatric populations. Instrument development has easily paralleled the growth and development of the ureteroscope and has improved success, patient safety, and comfort with the incorporation of access sheaths, nitinol materials, and Ho:YAG laser technology. Owing to their minimal morbidity and high success rate, ureteroscopic evaluation and therapeutic interventions in the upper tract represent the gold standard of management. Albert Einstein said, "There are only two ways to live your life. One is as though nothing is a miracle. The other is as though everything is a miracle." Contemporary ureteroscopy is a historical miracle that has opened a vista of endless limits in upper tract endoscopy (Fig. 4, Box 1).

Ureteroscopic treatment of renal calculi.

Although ureteroscopic treatment of renal calculi is safe and effective. it is relatively inefficient compared with ESWL and PCNL. It should be considered primary therapy for patients with lower pole stones who have adverse ESWL characteristics and patients who are not suitable candidates for PCNL. There are also numerous clinical situations, as outlined previously, where the ureteroscopic approach is favored over other treatment modalities.

Image converter eliminates mirror imaging during laparoscopy.

BACKGROUND AND PURPOSE: In laparoscopy, the term "mirror imaging" is used to describe a visual illusion resulting in paradoxical movements when a surgeon is positioned opposite the laparoscope. Mirror imaging is a common problem, creating difficulty in ergonomics and task performance. We introduce the use of a video image converter box (IC box) to overcome mirror imaging. The IC box converts the analog signal to a digital one, performs image rotation or inversion or both, and then reproduces an analog signal for monitor viewing. A laboratory study evaluated whether the IC box could improve performance during laparoscopic tasks. MATERIALS AND METHODS: Fourteen laparoscopic surgeons (10 novice and 4 experienced) completed three laparoscopic tasks while positioned opposite the camera and experiencing mirror imaging: (1). suture cutting; (2). multiple transfers of a piece of foam; and (3). multiple transfers of a pinto bean. Participants were timed during each test both with and without the use of the IC box. RESULTS: All surgeons completed each task faster using the IC box (P < 0.015). On average, use of the IC box allowed subjects to complete assignments in less than one-third the time needed without the IC box. In Task 3, requiring multiple transfers of a small bean, all participants using the IC box completed the task. However, without the box, only 1 of 14 participants accomplished the goal in the allotted time. CONCLUSION: Use of the IC box eliminates mirror imaging and improves performance and efficiency during laparoscopic tasks. The box would significantly benefit surgeons positioned opposite the camera during laparoscopic surgery.

Intestinal Oxalobacter formigenes colonization in calcium oxalate stone formers and its relation to urinary oxalate.

BACKGROUND AND PURPOSE: Oxalobacter formigenes is an anaerobic commensal colonic bacterium capable of degrading oxalate through the enzyme oxalyl-CoA decarboxylase. It has been theorized that individuals who lack this bacterium have higher intestinal oxalate absorption, leading to a higher urinary oxalate concentration and an increased risk of calcium oxalate urolithiasis. We performed a prospective, controlled study to evaluate O. formigenes colonization in calcium oxalate stone formers and to correlate colonization with urinary oxalate and other standard urinary stone risk factors. PATIENTS AND METHODS: Thirty-five first-time calcium oxalate stone formers were compared with 10 control subjects having no history of urolithiasis and a normal renal ultrasound scan. All subjects underwent standard metabolic testing by submitting serum and 24-hour urine specimens. In addition, all subjects submitted stool samples for culture and detection of O. formigenes by Xentr(ix) O. formigenes Monitor. RESULTS: Intestinal Oxalobacter was detected in only 26% of the stone formers compared with 60% of the controls (p < 0.05). Overall, the average urinary oxalate excretion by the two groups was similar (38.6 mg/day v 40.8 mg/day). Among stone formers, however, there were statistically higher urinary oxalate concentrations in O. formigenes-negative patients compared with those testing positive (41.7 mg/day v 29.4 mg/day) (p = 0.03). Furthermore, all 10 stone formers with hyperoxaluria (>44 mg/day) tested negative for O. formigenes (p < 0.05). CONCLUSIONS: Calcium oxalate stone formers have a low rate of colonization with O. formigenes. Among stone formers, absence of intestinal Oxalobacter correlates with higher urinary oxalate concentration and an increased risk of hyperoxaluria. Introduction of the Oxalobacter bacterium or an analog of its enzyme oxalyl-CoA decarboxylase into the intestinal tract may be a treatment for calcium oxalate stone disease.

Correlation of ureteral stone measurements by CT and plain film radiography: utility of the KUB.

BACKGROUND AND PURPOSE: The practice of utilizing helical CT to evaluate patients suspected of renal colic is increasing. Little is known about the accuracy of CT in estimating stone size or the utility of an accompanying plain abdominal radiograph (KUB film). The purpose of our study was to compare ureteral stone size estimation by helical CT and plain film and determine whether a KUB film provides additional information useful in patient management. PATIENTS AND METHODS: Thirty consecutive patients (17 male, 13 female) having both a helical CT and a KUB study for evaluation of renal colic secondary to ureteral calculi comprised the study population. Calculus number, location, and dimensions were determined from these images. Stone dimensions were measured using electronic calipers on a picture archiving and communications system. Information found by KUB and CT was compared, and both sets of stone measurements were correlated with patient outcome. RESULTS: The mean maximal stone transverse diameter and length were similar on CT and plain film: 5.8 mm v 5.8 mm and 9.5 mm v 8.9 mm, respectively (P = 0.57 and 0.29, respectively). The mean anteroposterior stone diameter on CT of 6.8 mm was statistically greater than the transverse diameter as measured by both CT and KUB, which were 5.8 mm and 5.8 mm (P = 0.0002 and 0.0007, respectively). Eleven patients spontaneously passed their stones, while 19 patients required intervention. Patient outcome, as predicted by transverse stone width, was similar for CT and KUB data. CONCLUSIONS: The management of patients with ureteral calculi relies on estimated stone size and the stone's potential for spontaneous passage. Stone dimensions estimated by CT are similar to the size determined by plain film radiography. Although plain film radiography does not provide information on stone dimensions beyond that obtained with CT, it does reveal precise stone location and radiolucency, data helpful in following and treating patients.

Renal intrapelvic pressure during percutaneous nephrolithotomy and its correlation with the development of postoperative fever.

PURPOSE: Systemic absorption of irrigation fluid containing bacteria or endotoxin may lead to fever and urosepsis after percutaneous nephrolithotomy. Although to our knowledge the exact method of absorption is undefined, intrapelvic pressure greater than 30 mm. Hg has been shown to result in pyelovenous-lymphatic backflow. We measured intrapelvic pressure during percutaneous nephrolithotomy and correlated pressure with postoperative fever and operative technique. MATERIALS AND METHODS: Intrarenal pressure was measured with a transurethral 7Fr ureteral occlusion balloon catheter and a urodynamic system during percutaneous renal access, rigid and flexible nephroscopy, and intracorporeal lithotripsy. Postoperative fever was correlated with elevated intrarenal pressure, stone type and surgical technique. RESULTS: Enrolled in this study were 18 women and 13 men. Pressure greater than 30 mm. Hg was recorded in 8 patients (26%). Elevated pressure occurred under 2 conditions, namely incomplete positioning of the nephroscopy sheath within the collecting system and endoscopy through a narrow infundibulum. In 13 cases (42%) a fever of 38C or greater developed postoperatively. Elevated pressure did not correlate with fever. However, of those undergoing percutaneous nephrolithotomy for the removal of infection versus noninfection stones 64% and 24%, respectively, had fever postoperatively. CONCLUSIONS: Renal intrapelvic pressure generally remains low during percutaneous nephrolithotomy. Elevated pressure was associated with incomplete nephroscopy sheath positioning within the collecting system and endoscopy through an infundibular narrowing. There was no association of renal pressure greater than 30 mm. Hg with fever but postoperative fever and percutaneous nephrolithotomy done for infection related stones correlated significantly.