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Stevan B Streem

Publications and source records attributed to Stevan B Streem.

At least 19 recordsLinked to original sources
PubMed2007

The role of computerized tomographic urography in the initial evaluation of hematuria.

PURPOSE: We determined the usefulness of computerized tomographic urography for the initial evaluation of patients with hematuria as an alternative to excretory urography. MATERIALS AND METHODS: A total of 259 patients (140 men and 119 women), age range 20 to 100 (mean 59.4) years, underwent computerized tomographic urography for the evaluation of hematuria and were available for followup. A cohort of 253 patients (153 men, 100 women), age range 21 to 92 (mean 57.6) years, underwent conventional excretory urography and were evaluated for comparison. RESULTS: A source of hematuria was identified in 107 patients (41.3%) in the computerized tomographic urography cohort and in 103 patients (40.7%) in the excretory urography cohort. Computerized tomographic urography alone identified a source of hematuria in 25.5% of these patients with the most commonly diagnosed lesions being renal calculi (18.9%), ureteral calculi (2.7%) and renal pelvic masses (2.3%) in the upper tract (0.94 sensitivity), and bladder masses (8.1%), prostatic abnormalities (5.4%) and inflammatory disorders (3.5%) in the lower tract (0.40 sensitivity, 0.99 specificity). The overall detection rate (19.5%), most commonly diagnosed lesions, and lower urinary tract sensitivity and specificity were similar in the excretory urography cohort. However, excretory urography exhibited a markedly lower sensitivity in detecting upper tract lesions (0.50). CONCLUSIONS: Computerized tomographic urography exhibited a significantly higher sensitivity than conventional excretory urography in detecting upper tract pathology (94.1% vs 50%). However, sensitivity for detecting lower tract lesions was low (40% or less), suggesting that computerized tomographic urography offers a comprehensive alternative to excretory urography but does not obviate the need for adjunctive cystourethroscopy for accurate evaluation of the lower urinary tract.

Female↗
PubMed2006

Long-term efficacy of holmium laser endoureterotomy for benign ureteral strictures.

OBJECTIVES: To determine the long-term clinical and radiographic success of holmium laser endoureterotomy for nonobliterative benign ureteral strictures. METHODS: A total of 19 patients (12 women and 7 men, mean age 47.5 years) underwent holmium laser endoureterotomy for iatrogenic ureteral strictures (seven proximal, seven mid, and five distal) using semirigid ureteroscopy and a 360-microm fiber at 1 J and 10 Hz. RESULTS: Success was strictly defined as both relief of symptoms and radiographic resolution of obstruction by intravenous pyelography or diuretic renography, or both. With a median follow-up of 3.0 years, success was achieved in 13 (68.4%) of 19 patients. CONCLUSIONS: Our results have shown that holmium laser endoureterotomy is associated with a long-term success rate equivalent to, or better than, other currently available minimally invasive treatment options. Also, failure was uniformly evident within the first 3 months after treatment.

Adult↗
PubMed2006

Repair of adult ureteropelvic junction obstruction in the solitary kidney: effect on renal function.

OBJECTIVES: To evaluate the effect of pyeloplasty for the treatment of ureteropelvic junction (UPJ) obstruction on adult renal function in the setting of a solitary kidney. METHODS: Since 1989, 312 patients have undergone operative intervention for UPJ obstruction. Of these, 13 patients (5 men and 8 women), aged 17 to 76 years (median 44.5), had a solitary kidney and were available for postoperative surveillance. Treatment consisted of endopyelotomy (n = 3), laparoscopic dismembered pyeloplasty (n = 3), and open dismembered pyeloplasty (n = 9). Two patients underwent two separate interventions for UPJ obstruction repair. Success was defined as symptomatic relief and radiographic resolution at the latest follow-up visit. In all patients, serum creatinine, estimated glomerular filtration rate, and weight were measured preoperatively, postoperatively, and at all follow-up examinations. Statistical analysis was performed to analyze group differences using the Wilcoxon signed-rank test. RESULTS: The median follow-up was 22 months (range 2 to 96). Three patients experienced a treatment failure and were excluded from the analysis. At the latest follow-up visit, the postoperative serum creatinine had improved by a median of 0.6 mg/dL (range -0.2 to 6.3; P <0.0001), and postoperative estimated glomerular filtration rate had improved by a median of 24.4 mL/min (range -13.9 to 66; P <0.0001). No statistically significant difference in renal function was observed between the patients' first and last follow-up visits. CONCLUSIONS: Operative intervention for the treatment of adult UPJ obstruction may result in symptomatic relief and, perhaps more importantly, renal functional improvement. These findings are important for effectively counseling patients and considering indications for intervention.

Adolescent↗
PubMed2006

External validation of outcome prediction model for ureteral/renal calculi.

PURPOSE: We externally validated a previously designed neural network model to predict outcome and duration of passage for ureteral/renal calculi. The model was also evaluated using a 6 mm largest stone dimension cutoff in predicting stone outcome. MATERIALS AND METHODS: The model was previously designed on 301 patients at Albany Medical Center (free shareware from www.uroengineering.com). The model had a prediction accuracy of 86% for passage outcome and 87% for passage duration. In this study we tested the model on a separate 384 patients from 6 different external institutions to assess the prediction accuracy. All patients had a single renal/ureteral calculus by evaluation in an emergency room setting or by primary physicians and were then referred for further treatment. Model accuracy was also compared to using a 6 mm largest stone dimension cutoff in predicting the need for intervention. RESULTS: Testing on the 384 patients from all 6 external institutions revealed an outcome prediction accuracy of 88%. The area under the ROC curve was 0.9. Using a 6 mm stone size cutoff provided 79% (ROC 0.8) accuracy. The model duration of passage prediction accuracy was 80% (133 patients passed the stone, area under ROC of 0.8). CONCLUSIONS: The model provided high stone outcome prediction accuracy (ROC of 0.9 and 0.8) at the 6 external institutions, comparable to that of the design institution. The model provided higher accuracy than using only the largest stone dimension as a cutoff. Increasing experience will further assess the model's accuracy.

Adolescent↗
PubMed2006

Retrograde endopyelotomy: a comparative study of hot-wire balloon and ureteroscopic laser.

PURPOSE: This study compared the immediate and long-term results and complications of hot-wire balloon endopyelotomy and ureteroscopic holmium laser endopyelotomy. PATIENTS AND METHODS: Between March 1994 and January 2002, 64 patients with a primary (N = 52) or secondary (N = 12) ureteropelvic junction obstruction underwent retrograde endopyelotomy using either a fluoroscopically guided hot-wire balloon incision (N = 27) or a ureteroscopically guided, direct-vision holmium laser incision (N = 37). This study group included 46 women and 18 men aged 13 to 79 years (mean 38.9 years). The indications and contraindications to a retrograde approach were identical in each group and included documented functionally significant evidence of obstruction, no upper-tract stones, obstruction <2 cm, and no radiographic evidence of entanglement of crossing vessels at the ureteropelvic junction. Immediate and long-term outcomes were obtained from a prospective registry, with success defined as resolution of symptoms and radiographic relief of obstruction as determined by follow-up with intravenous urography, diuretic renography, or both. Follow-up ranged from 39 to 133 months (mean 75.6 months). RESULTS: Length of hospital stay, indwelling stent duration, and long-term success rates (77.8% v 74.2% in the hot-wire balloon and holmium-laser group, respectively) were equivalent. However, two patients in the hot-wire balloon group developed bleeding necessitating transfusion and selective embolization of lower-pole vessels. No patient in the ureteroscopic group suffered a major complication. CONCLUSIONS: These two alternatives for retrograde endopyelotomy provide comparable success rates for similarly selected patients. However, because significant hemorrhagic complications developed with greater frequency in those treated with the hot-wire balloon, our preference is for a ureteroscopic approach, as it allows direct visual control of the incision and thus, a lower risk of significant bleeding.

Adolescent↗
PubMed2005

Ureterocalicostomy: a contemporary experience.

OBJECTIVES: To report our contemporary experience with ureterocalicostomy to determine whether the indications or results have changed in modern practice. Ureterocalicostomy is a well-established treatment for patients with complicated ureteropelvic junction (UPJ) obstruction and other forms of proximal ureteral obstruction. Although both retrograde and antegrade endourologic interventions have become accepted forms of management, the success rates do not approach those of open or even laparoscopic interventions, potentially leading to a greater number of patients with treatment failure and the need for more complicated reconstruction. METHODS: Between July 1991 and February 2004, 11 patients (4 women and 7 men), aged 19 to 68 years (mean 38), underwent open surgical ureterocalicostomy. The indications for surgery were primary UPJ obstruction in 4, failed cutting balloon incision for UPJ obstruction in 3, proximal ureteral stricture after ureteroscopic stone removal in 2, and obliterated UPJ after percutaneous nephrolithotomy and failed antegrade endopyelotomy in 1 patient each. RESULTS: Hospitalization ranged from 4 to 7 days (mean 5.1). No patient experienced a significant perioperative complication. With follow-up ranging from 5 to 32 months (mean 10.1), relief of obstruction was evident in all patients as documented by intravenous urography or nuclear renography. Furthermore, differential function on the involved side improved from a mean of 54.6% preoperatively to 60.1% postoperatively (P <0.05). CONCLUSIONS: The spectrum of indications for ureterocalicostomy has changed, although excellent results can still be achieved. Although laparoscopic approaches are currently being evaluated, most patients currently undergoing this reconstructive procedure still require open operative intervention.

Adult↗
PubMed2005

Laparoscopic live donor nephrectomy has equivalent early and late renal function outcomes compared with open donor nephrectomy.

OBJECTIVES: To assess the patterns of early functional recovery and long-term function in laparoscopic and open procured live donor nephrectomy (LDN) kidneys, highlighting the radionuclide scan as an additional tool for assessment, because of concerns regarding renal functional recovery after laparoscopic LDN. METHODS: We reviewed the donor and recipient records of 101 laparoscopic and 35 open LDNs performed between August 1997 and September 2001. Data were collected on demographic, immunologic, and intraoperative variables and ureteral/vascular complications. Delayed renal function recovery in recipients was evaluated by serum creatinine greater than 2.5 mg/dL on postoperative day 5, dialysis in first postoperative week, and two renographic criteria--the time to peak activity and the time to one-half peak activity on postoperative day 5. Long-term outcomes were evaluated by serum creatinine at 1, 3, 6, and 12 months and 2 and 3 years, creatinine clearance at 1 year, and patient and allograft survival. RESULTS: Donor and recipient age, sex, body mass index, and number of HLA mismatches did not differ between the two groups. The mean operating room time and blood loss were comparable. No differences were found in the early functional parameters (renography, creatinine at postoperative day 1 and 5, or dialysis in week 1) or long-term outcome (patient and graft survival, creatinine, and rejection at 1 year and patient and graft survival at 1, 2, and 3 years). CONCLUSIONS: Early recovery of graft function, longer term renal function, and 3-year patient and allograft survival are similar for live donor kidneys obtained by either a laparoscopic or an open surgical technique.

Adult↗
PubMed2005

Novel endourologic applications for holmium laser.

The holmium laser is used routinely during endoscopic procedures to treat stones, strictures, and tumors of the urinary tract. We report two successful novel endourologic applications of a holmium laser: division and removal of a synthetic urethral sling mesh in one patient and fragmentation of a tempered stainless steel surgical needle in another.

Adult↗
PubMed2005

Ureteropelvic junction obstruction after partial nephrectomy.

BACKGROUND AND PURPOSE: As the experience with partial nephrectomy continues to grow and the procedure increasingly becomes the standard of care for properly selected patients, it is critical to understand the potential complications and how these complications are best managed. Presented herein is the presentation, work-up, and treatment of ureteropelvic junction (UPJ) obstruction after partial nephrectomy. PATIENTS AND METHODS: From 1993 to 2004, 1154 partial nephrectomies have been performed at our institution by one surgeon. From the database of these patients, four (0.35%) were identified with postoperative UPJ obstruction. The charts of these patients were reviewed to identify preoperative and intraoperative characteristics as they relate to the development and risk of UPJ obstruction. Additionally, the presentation of UPJ obstruction, its management, and long-term follow-up are reported. RESULTS: Tumor location in the lower pole appears to be a risk factor for the development of UPJ obstruction, which is likely a result of ischemic or mechanical injury. This complication was managed successfully by endoscopic approaches in three of four cases. At a mean follow-up of 43 months, all patients remain free of obstruction according to both the absence of symptoms and radiographic evidence. CONCLUSION: Obstruction of the UPJ is an uncommon complication of partial nephrectomy. Endoscopic treatment of this complication yields a durable outcome, as all patients with a mean follow-up of more than 3 years show resolution of their obstruction.

Adult↗
PubMed2005

Percutaneous access to upper pole renal stones: role of prone 3-dimensional computerized tomography in inspiratory and expiratory phases.

PURPOSE: We evaluated the role of noncontrast, prone position, inspiratory and expiratory 3-dimensional spiral computerized tomography (PIE-CT) for preoperative planning of percutaneous treatment in patients with complex upper pole renal calculi. MATERIALS AND METHODS: In this pilot study a total of 6 renal units in 4 women and 1 man with complex upper pole calculi who were candidates for percutaneous nephrolithotomy were evaluated with thin section PIE-CT. With the patient imaged in the prone position percutaneous access was simulated under 4 potential access conditions, including subcostal and intercostal, in inspiration and expiration. Each potential access was then deemed transpleural or extrapleural and minimally angulated or severely angulated cephalad. RESULTS: PIE-CT was performed uneventfully in all patients. Ideal nonangulated extrapleural percutaneous access was deemed possible in 5 of 6 renal units. However, inspiratory plus expiratory phases were necessary to identify the most suitable access site. In 2 renal units only 1 safe access site was identified. No pulmonary complications were noted in any of these patients. In 1 renal unit no suitable access could be identified and this patient was treated with laparoscopic caliceal diverticulectomy. CONCLUSIONS: Thin section PIE-CT offers 3-dimensionally rendered images that clearly demonstrate anatomical relationships among the kidney, calculi, pleura, diaphragm, ribs and surrounding organs. In this pilot study PIE-CT provided useful data for planning urological intervention for complex upper pole renal stones. This study also suggests that generalizations regarding the safety of upper pole access in the inspiratory or expiratory phase are not warranted.

Exhalation↗
PubMed2005

Jejunoileal bypass reversal: effect on renal function, metabolic parameters and stone formation.

PURPOSE: While the effect of jejunoileal bypass (JIB) reversal has been well studied regarding hepatic function, there is little information regarding the effect of reversal on renal function and even less data regarding the metabolic urinary stone environment. We evaluated the results of JIB reversal on renal function, the urinary stone milieu and the clinical development of recurrent calculi in affected patients. MATERIALS AND METHODS: From 1995 to 2003, 4 female patients with a mean age of 48.2 years underwent JIB reversal primarily for refractory stone disease. The clinical and metabolic courses prior to and following bypass reversal were reviewed specifically to evaluate renal function, serum and urinary metabolic stone profiles, and clinical stone formation. RESULTS: At initial presentation following JIB all 4 patients had significantly increased 24-hour urinary oxalate (range 80 to 160 mg, mean 112.5, normal less than 50) and significantly low 24-hour urinary citrate (range 5 to 62 mg, mean 21.5, normal greater than 320). Following reversal 24-hour urinary oxalate normalized to between 31 and 36 mg (mean 33.75). However, 24-hour urinary citrate continued to be low (range 215 to 248 mg, mean 226.5). After JIB reversal all 4 patients continued to have new stones until the commencement of urinary alkalization, following which only 1 had 1 calculus, which occurred 47 months after reversal. After JIB mean serum creatinine was 1.48 mg/dl (range 0.8 to 1.9) and mean urinary creatinine excretion was 0.91 mg per hour (range 0.69 to 1.15). After JIB reversal mean serum creatinine was 1.28 mg/dl (range 0.6 to 2.0) and mean urinary creatinine excretion was 1.0 mg per hour (range 0.85 to 1.10). CONCLUSIONS: JIB reversal normalizes 24-hour urinary oxalate. While urinary citrate improves, it continues to be low and such patients are at high risk for recurrent stone formation. However, in this setting appropriate replacement therapy has a significant and positive impact on that propensity.

Adolescent↗
PubMed2004

Idiopathic ureteral strictures without evidence of malignancy.

Benign strictures of the ureter without known antecedent cause are rare. In the absence of prior instrumentation, infection, radiotherapy, or ureteral calculi, strictures intrinsic to the ureter are usually of malignant origin. We describe two recent cases of idiopathic ureteral strictures without evidence of malignancy.

Anastomosis, Surgical↗
PubMed2004

Metastatic cancer to the renal pelvis: a novel approach to management.

We describe a novel application of percutaneous renal surgery for the management of an unusual and challenging urologic problem. Two patients with symptomatic, metastatic adenocarcinoma in the renal pelvis were treated with percutaneous resection. The lesion was in a solitary kidney in 1 patient, and was bilateral in the second. Percutaneous resection resulted in complete relief of symptoms and obstruction. Although both patients ultimately died of their primary disease, their quality of life was significantly improved in the interim. Percutaneous resection of renal pelvic tumors is accepted management for select patients with upper tract transitional cell carcinoma. These 2 cases demonstrated both an unusual presentation for metastatic adenocarcinoma and an expanded application for percutaneous renal surgery.

Adenocarcinoma↗
PubMed2004

Ureteropelvic junction obstruction: endourologic relocation of laterally inserting ureters.

PURPOSE: To describe a technique of endourologic management for ureteropelvic junction (UPJ) obstruction associated with lateral insertion of the ureter. PATIENTS AND METHODS: Among 57 patients with primary UPJ obstruction selected to undergo retrograde endopyelotomy, 2 patients (3.5%) demonstrated a nondilated ureter inserting laterally along a hydronephrotic renal pelvis on retrograde pyelography. Using the hot-wire balloon catheter in one and a holmium laser inserted ureteroscopically in one, retrograde endopyelotomy was performed with the incision directed medially in order to marsupialize the ureter into the renal pelvis and to relocate the UPJ to the dependent portion of the medial aspect of the renal pelvis. RESULTS: The hospital stay for both patients was 1 night, and there were no complications. The stent was removed 4 or 6 weeks postoperatively. Intravenous urography 6 weeks thereafter demonstrated relocation of the UPJ to a medial and dependent position, associated with prompt drainage of contrast medium and decreased pelvocaliectasis compared with preoperative studies. Both patients are asymptomatic. CONCLUSIONS: In cases of primary UPJ obstruction associated with lateral insertion of the ureter, the UPJ can be relocated to the medial and dependent portion of the renal pelvis using minimally invasive endourologic techniques. The dictum of performing a endopyelotomy incision laterally does not hold true in all patients and may compromise functional outcomes in cases where the ureteral insertion is nondependent and laterally positioned.

Adult↗
PubMed2004

Ureteropelvic junction obstruction: determining durability of endourological intervention.

PURPOSE: We evaluated the durability of endourological intervention for ureteropelvic junction obstruction and established guidelines for postoperative surveillance. MATERIALS AND METHODS: Since 1989, 150 patients have undergone endourological intervention for ureteropelvic junction obstruction, of whom 127 (53 men and 74 women) 13 to 79 years old (mean age 40.4) underwent postoperative evaluation at our center. These 127 patients are the study group reported. Endourological management consisted of hot wire balloon endopyelotomy in 25 patients, percutaneous endopyelotomy in 67 and ureteroscopic laser endopyelotomy in 35. Success in this study was strictly defined as symptomatic relief plus radiographic resolution on excretory urogram and/or diuretic renogram. Statistical analysis was performed to assess mean time to failure and develop Kaplan-Meier re-stenosis-free survival estimates. RESULTS: Followup was 1 to 128 months (mean 22). Time to failure was 0.9 to 32.4 months (mean +/- SD 10.3 +/- 9.4). Kaplan-Meier estimates of time to re-stenosis (failure) were 6 months in 12% of patients, 12 in 22%, 18 in 24%, 24 in 27%, 30 in 32% and 36 in 37%. After 3 years no further failures were observed and Kaplan-Meier estimates remained unchanged. CONCLUSIONS: The long-term probability of success, which is estimated to be 63.3% in this series, is somewhat lower than that reported in the literature. It likely is a result of longer followup and a more strict definition of success that includes functional and symptomatic relief. Our data suggest that while most failures become evident within the first 12 months, failure can develop as late as 3 years after intervention. As such, patients should be followed at least that long to ensure a durable result.

Adolescent↗
PubMed2004

A multivariate analysis of risk factors associated with subcapsular hematoma formation following electromagnetic shock wave lithotripsy.

PURPOSE: Subcapsular or perinephric hematoma is one of the most frequent and potentially serious complications of extracorporeal shock wave lithotripsy (SWL). We determined the incidence of and risk factors for renal hematomas following electromagnetic shock wave lithotripsy. MATERIALS AND METHODS: Between February 1999 and August 2003, 570 SWL treatments were performed using a Modulith SLX electromagnetic lithotriptor (Storz, St. Louis, Missouri). A total of 415 of these treatments in 317 patients were performed for stones in the renal pelvis or calices and these treatment episodes represent the study group reported. Treatment episodes were reviewed from a prospective institutional review board approved registry and analyzed for patient age, gender, body mass index, mean arterial pressure at induction, stone location, total number of shock waves and peak shock wave intensity. RESULTS: Following these 415 episodes subcapsular or perinephric hematomas developed in 17 patients for an overall incidence of 4.1%. The probability of hematoma after shock wave lithotripsy increased significantly as patient age at treatment increased, such that the probability of hematoma was estimated to be 1.67 times greater for each 10-year incremental increase in patient age. None of the other variables analyzed were significantly related to the incidence of hematoma formation at the 0.05 level. CONCLUSIONS: The incidence of renal hematoma formation following electromagnetic SWL for renal calculus was 4.1%. The probability of hematoma increased significantly with increasing patient age but it was not associated with increasing mean arterial pressure at treatment. These findings are in contrast to previous reports of hematoma associated with electrohydraulic SWL. These differences may be a consequence of the smaller focal zone and higher peak pressure associated with Storz Modulith electromagnetic SWL and, just as importantly, a consequence of the difference in the manner in which blood pressure was defined.

Adolescent↗
PubMed2003

Management of failed primary intervention for ureteropelvic junction obstruction: 12-year, single-center experience.

OBJECTIVES: To compare contemporary endourologic and open surgical management of failed primary intervention for ureteropelvic junction obstruction, specifically in regard to immediate and long-term results and complications. METHODS: Since 1989, 48 patients have undergone management of failed primary intervention for ureteropelvic junction obstruction. Of these, 42 patients (21 females and 21 males; age range 16 to 68 years, mean age 34.9) underwent follow-up evaluations. These 42 patients constitute the present study group. The mode of secondary intervention was determined by individual upper tract anatomy, concurrent medical conditions, and informed patient preference. Secondary intervention included open operative repair (n = 20) or percutaneous (n = 11), ureteroscopic (n = 5), or retrograde cautery wire balloon (n = 6) endopyelotomy. Success was defined as symptomatic relief and improved calicectasis on radiographic evaluation at latest follow-up. RESULTS: Follow-up ranged from 6 to 148 months (mean 47.7). Endourologic intervention was associated with a mean hospital stay of 2.3 nights and a complication rate of 13.6%. The long-term success rate of these endoscopic approaches was 59.1% overall, including a 71.4% success rate after a failed open operative procedure and a 37.5% success rate after a failed endourologic procedure. In contrast, open operative salvage was associated with a mean stay of 4.3 nights and a 15% complication rate. The success of open operative salvage was 95% overall, including 94.1% after failed endourologic intervention and 100% after failed open operative intervention. CONCLUSIONS: Endourologic intervention for failed primary management of ureteropelvic junction obstruction is associated with a short hospital stay and low rate of complications. Such intervention provides acceptable success rates in the setting of prior failed open operative intervention. However, when endourologic salvage was used for prior failed endourologic intervention, the success rates were limited. This suggests that intrinsic factors such as crossing vessels or periureteral fibrosis may play a role in limiting the utility of such procedures in this setting. In contrast, open operative salvage after any prior failed intervention for ureteropelvic junction obstruction provides excellent functional results without any increase in morbidity, with, in this contemporary series, an acceptably short hospital stay. These data should help urologists and patients make well-informed treatment decisions.

Adolescent↗