PubMed Health⌕ Search

Biomedical subjects

B K Hollenbeck

Publications and source records attributed to B K Hollenbeck.

9 recordsLinked to original sources
PubMed2001

Complications of ureteroscopy: analysis of predictive factors.

PURPOSE: Although overall and major complication rates of 10% to 20% and 0% to 6%, respectively, have been observed in large series of ureteroscopy, to our knowledge no systemic analysis to determine factors predictive of these complications has been reported. MATERIALS AND METHODS: We retrospectively reviewed all ureteroscopies performed at our institution for calculous disease from January 1997 through September 1999. A total of 322 procedures were performed by 5 attending surgeons. Intraoperative and immediate postoperative complications were identified. Bivariate and multivariate analysis was performed to identify associated factors with ureteral perforation and postoperative complications as the dependent variables. RESULTS: Bivariate analysis showed a significant association of ureteral perforation with increased operative time (p = 0.0001). In addition, we noted a significant association of postoperative complications with stones in the kidney (p = 0.0004), operative time (p = 0.05) and decreased surgeon experience (p = 0.0035) as well as a trend toward significance for the type of ureteroscope used (p = 0.0609). In multivariate logistic regression models ureteral perforation remained highly associated with operative time (p = 0.0005) when controlling for the other factors. Similarly decreased surgeon experience and a stone in the kidney were predictive of postoperative complications when controlling for the other factors (p = 0.004). CONCLUSIONS: Longer duration of the ureteroscopic procedure is strongly associated with ureteral perforation. The likelihood of immediate postoperative complications is greater when renal calculi are treated and less when the surgeon is more experienced.

Adult↗
PubMed2001

Routine placement of ureteral stents is unnecessary after ureteroscopy for urinary calculi.

OBJECTIVES: To report a matched comparison of patients with and without stenting after ureteroscopy for calculi, including middle or proximal ureteral and renal calculi. The elimination of routine stenting after ureteroscopy would prevent stent pain, minimize the need for re-instrumentation, and reduce costs-as long as efficacy and safety are not diminished. METHODS: Of 318 patients who underwent ureteroscopy, 81 (25%) did not have a ureteral stent placed. Of those, 51 were suitable for analysis and included patients with distal ureteral (n = 22), middle or proximal ureteral (n = 11), and renal calculi (n = 18). This cohort was matched to a stented group by stone size and location. RESULTS: The preoperative characteristics of the groups were similar. A stone-free rate of 86% and 94% was achieved in the stented and nonstented groups, respectively (P = 0.32). Complications in the nonstented group were less frequent (flank pain in 3 and postoperative nausea in 1) than in the stented group (hospital visits for flank pain in 12, persistent nausea and vomiting in 1, sepsis in 1, perinephric hematoma in 1, and urinary retention in 1) (total of 4 versus 16, P = 0.025). CONCLUSIONS: Ureteroscopy for distal ureteral stones without ureteral stent placement has been previously described. Our experience expands to include the elimination of stent placement after ureteroscopy for middle or proximal ureteral (22%) and renal (35%) calculi. Our data suggest that after ureteroscopies with short operative times and minimal ureteral trauma, ureteral stents may not be necessary, even if proximal ureteral or renal ureteroscopy has been performed.

Follow-Up Studies↗
PubMed2001

Comparison of outcomes of ureteroscopy for ureteral calculi located above and below the pelvic brim.

OBJECTIVES: To compare the safety and efficacy of ureteroscopy performed for proximal and distal ureteral calculi in a contemporary cohort. Ureteroscopy has been used most often for distal ureteral calculi. However, advances in endoscopic equipment have facilitated access to the proximal urinary tract and have broadened the indications for ureteroscopy. METHODS: One hundred ninety-one patients underwent rigid and/or flexible ureteroscopy for ureteral calculi at the University of Michigan between January 1, 1997 and September 30, 1999. Only 7 patients with either bilateral calculi or steinstrasse were excluded. The final cohort consisted of 184 patients who underwent ureteroscopy for distal stones (n = 103) or middle/upper ureteral stones (n = 81). RESULTS: Bivariate analyses of pretreatment and perioperative characteristics were used to assess the sample population. The initial success rate for the distal and proximal ureteral calculi was 96% and 78%, respectively (P = 0.0008). After a "second-look" procedure in 4 and 7 patients with distal and proximal calculi, respectively, the success rate improved to 99% and 88%, respectively (P = 0.004). No differences were noted between groups regarding the intraoperative (P = 0.51) or postoperative (P = 0.85) complication rates. Multivariate logistic regression analysis confirmed that larger stone size (odds ratio 1.2, P = 0.0006) and proximal ureteral location (odds ratio 4.8, P = 0.01) are independent predictors of treatment failure. CONCLUSIONS: Ureteroscopic management of proximal and distal ureteral calculi is highly successful, and the difference in success rates has narrowed substantially. Currently, no greater risk is conferred to the patient for endoscopy of more proximal ureteral calculi.

Adult↗
PubMed2001

Flexible ureteroscopy in conjunction with in situ lithotripsy for lower pole calculi.

OBJECTIVES: To demonstrate the efficacy and safety of ureteroscopy as a compromise in treating small and intermediate-size lower pole calculi. The optimal management of lower pole calculi remains controversial. Shock wave lithotripsy is associated with minimal morbidity but with suboptimal stone clearance rates. Conversely, percutaneous nephrostolithotomy has greater morbidity but stone-free rates greater than 90% regardless of size. METHODS: Seventy-two patients underwent ureteroscopy for lower pole calculi 2 cm or less (mean 8.7 mm) during a 3-year period. To minimize confounding, 11 patients with additional calculi at other ipsilateral renal sites and 1 patient with large (2.4 cm each) bilateral calculi were excluded. Two patients with bilateral lower pole calculi and four who required a second procedure were included in the analysis. Thus, the final cohort consisted of 60 patients who underwent 66 procedures. RESULTS: Of patients with follow-up longer than 1 month, 79% were stone free after a single procedure, and this improved to 88% after a second procedure in 4 patients. All 7 patients with follow-up less than 1 month had a reduction in stone burden after successful fragmentation. Overall, 8 patients required an auxiliary procedure. No intraoperative complications, and 7 (11%) postoperative complications occurred. CONCLUSIONS: Ureteroscopy for lower pole calculi is associated with minimal morbidity and stone-free rates comparable to shock wave lithotripsy for smaller stones. The greatest utility of ureteroscopy is in the management of intermediate-size calculi, for which it has substantially higher stone-free rates and lower repeated treatment rates than does shock wave lithotripsy.

Chi-Square Distribution↗
PubMed2001

Laparascopic partial nephrectomy.

The role of laparoscopy in urologic surgery has greatly increased over the past decade as has the popularity of elective nephron-sparing surgery. The emergence of these trends in conjunction with improvements in equipment and expertise has led to the increasing application of laparoscopic partial nephrectomy. Initially, this modality was applied in patients with benign diseases, such as chronic pyelonephritis and calculus disease with associated atrophy. Concerns of tumor spillage and local-regional control precluded the application of the laparoscopic modality to small, indeterminate renal masses. However, increasing experience with the technique and advances in intraoperative imaging have prompted its use in removing small renal masses. Herein, we describe the indications for laparoscopic partial nephrectomy, the two approaches (transperitoneal and extraperitoneal) to gain access to the kidney, current options to assist in controlling intraoperative hemorrhage, a comprehensive assessment of the results for benign and malignant resections, and an examination of the similarities and contrasts between open and laparoscopic techniques.

Carcinoma, Renal Cell↗
PubMed2000

Use of a working channel catheter during flexible ureteroscopic laser lithotripsy.

PURPOSE: We describe a technique which protects the working channel of the flexible ureteroscope from damage caused by the laser fiber during laser lithotripsy. MATERIALS AND METHODS: A 2Fr catheter is placed into the working channel of the flexible ureteroscope. A 200 micro. laser fiber is then advanced through the lumen of the catheter and laser lithotripsy is subsequently performed. RESULTS: The catheter provides additional protection to the working channel sheath during passage and firing of the laser fiber. Deflection of the ureteroscope is not affected with the catheter in place. Movement of the laser fiber is augmented by the catheter when compared to movement of the fiber in the working channel alone. Irrigant flow is diminished with the catheter. CONCLUSIONS: The catheter does not appear to hinder performance of the flexible ureteroscope during laser lithotripsy. A catheter also offers additional protection to the working channel sheath, thereby potentially increasing the durability and working life of the flexible ureteroscope.

Humans↗
PubMed2000

Whole mounted radical prostatectomy specimens do not increase detection of adverse pathological features.

PURPOSE: The optimal method to process radical prostatectomy specimens to maximize the detection of adverse pathological features is unclear and accurate staging is critical. We compare the ability of whole mounted sections to detect these features compared to partially submitted radical prostatectomy specimens. MATERIALS AND METHODS: A total of 93 consecutive radical prostatectomy specimens were processed as whole mounts. Tissue sections were analyzed and the pathological outcomes measured included Gleason score, surgical margin status, and presence or absence of extraprostatic tumor extension and/or seminal vesicle invasion. The pathological outcomes of the preceding cohort were compared to those of a similar cohort consisting of 554 men whose radical prostatectomy specimens were processed as partially submitted glands. RESULTS: A multivariate logistic regression analysis was performed to determine the effect of the method of tissue processing on the pathological outcomes. When considered alone or adjusted for various preoperative patient characteristics (prostate specific antigen, biopsy Gleason score and clinical stage), there were no significant differences in the ability of whole mounted specimens to detect the various outcomes compared to partially submitted specimens (all p >0.4). CONCLUSIONS: Whole mounted sampling of the radical prostatectomy specimen does not improve detection of adverse pathological features.

Histocytological Preparation Techniques↗