Biomedical subjects

Vincent G Bird

Publications and source records attributed to Vincent G Bird.

15 recordsLinked to original sources

PubMed2026

Phentermine/Topiramate in Obese, Diabetic Uric Acid Stone Formers: An Open-Label Randomized Feasibility Trial.

PURPOSE: The purpose of this study was to determine whether medical treatment of obesity, diabetes, and low urine pH with combination phentermine/topiramate affects uric acid (UA) kidney stone burden. MATERIALS AND METHODS: Participants with obesity, diabetes mellitus, normal renal function, urine pH < 5.8, and stone analysis ≥ 80% UA were block randomized (2:1 ratio) to phentermine 18.75 mg/topiramate 100 mg vs pragmatic controls for an 18-month, prospective, open-label feasibility study with dose escalation. The primary outcome was change in CT stone volume. Secondary outcomes included medication adherence; patient safety; and change in anthropometrics, laboratory studies, and body composition. RESULTS: Nineteen participants (age 62.1 ± 9.8 years; 68% male; mean BMI = 36.3 ± 2.9 kg/m2) were randomized, and 15 completed the study with 73% pill adherence and no serious adverse events. Stone volume by intention-to-treat analysis fell by 52% in the intervention group and rose by 8.6% in the control group (P = .10), with per-protocol analysis demonstrating statistically significant stone volume reduction (P = .02). At study end and compared with means of controls, the intervention group had greater weight loss (-10.2 vs +2.9 kg), reduction in hemoglobin A1c levels (-0.2 vs +0.5), lower 24-hour urine citrate (309 ± 81 vs 951 ± 782 mg), and lower UA supersaturation (0.7 ± 1.1 vs 1.8 ± 1.0), along with higher 24-hour urine pH (6.2 ± 0.5 vs 5.5 ± 0.4) and calcium phosphate supersaturation (0.9 ± 0.8 vs 0.2 ± 0.1; all P < .05). CONCLUSIONS: Among obese participants with diabetes mellitus and UA nephrolithiasis, phentermine/topiramate was well tolerated and demonstrated significant stone burden reductions by per-protocol analysis. The intervention group also had greater weight loss, higher urinary pH, and lower hemoglobin A1c and urinary citrate levels. These data provide a framework to study the impact of this novel alternative UA therapy on a wider range of patients with obesity and diabetes.

Aged↗

PubMed2006

Frequency of ureteroscope damage seen at a tertiary care center.

PURPOSE: There is controversy regarding ureteroscope durability. Little is known regarding the subsequent durability of a flexible ureteroscope after major damage has been incurred and the ureteroscope has been repaired. Maintenance and repair are associated with significant cost. We reviewed and assessed the frequency and cause of ureteroscope damage at our medical center. MATERIALS AND METHODS: From December 2001 we prospectively recorded the specific use of all ureteroscopes and any resultant damage at a single tertiary care institution. We then reviewed a total of 601 ureteroscopic cases involving 654 semirigid and flexible ureteroscope uses from December 2001 to November 2004. Cases were performed by multiple residents and fellows under the supervision of 3 attending urologists (CML, RJL and VGB). Retrograde and antegrade cases involving stones, urothelial carcinoma, strictures and diagnostic evaluations were included. Repairs for the respective ureteroscopes were performed by the original manufacturer. RESULTS: A total of 53 reports of damage (8.1% of total uses) were recorded. Major damage when the scope was deemed unusable and required repair was seen in 39 cases (6.0%). Four newly purchased flexible ureteroscopes were entered into the study and they provided 40 to 48 uses before the initial repair was needed. After these new ureteroscopes underwent comprehensive repair for major damage they averaged only 11.1 uses (median 8) before needing repair again. Older model ureteroscopes that underwent repair before being entered into our study averaged between 4.75 and 7.7 uses before being sent for subsequent repair. Of the total of 39 breakages 39 for which ureteroscopes were sent for repair 14 (35.9%) were the result of errant laser firing, 11 (28.2%) were the result of excessive torque, 8 (20.5% 8) were the result of decreased flexion in the distal tip or another loss of function without obvious iatrogenic cause, 3 (7.7%) were the result of multifocal catastrophic damage involving laser firing and excessive torque, and 3 (7.7%) were the result of cleaning and processing outside of the ureteroscopy suite. CONCLUSIONS: The most important risk factors for predicting the number of uses expected from a ureteroscope at our institution is ureteroscope age and whether the ureteroscope has undergone comprehensive repair as the result of prior damage. Our analysis suggests that after damage occurs to a ureteroscope more damage occurs with greater frequency. The cost of maintaining previously used ureteroscopes should be carefully considered in comparison to the cost of purchasing a new ureteroscope.

Equipment Failure↗

PubMed2006

Endoscopic management of 10 separate fibroepithelial polyps arising in a single ureter.

INTRODUCTION: Fibroepithelial polyps of the ureter, usually of congenital or inflammatory origin, are rare entities. These polyps are often solitary, but cases of multiple polyps have also been reported. Treatment of these entities has evolved with emerging surgical techniques and technologies. SURGICAL TECHNIQUE: We describe our surgical technique for minimally invasive treatment of multiple polyps arising in a single ureter. The base of each polyp is ablated with a 365-microm holmium laser fiber operating at 10 W, and each polyp is removed from the ureteral wall with 3F grasping forceps. Hemostasis is achieved with laser coagulation. Ureteral stones are removed concurrently with a 2.4F basket. A 12/14F ureteral access sheath is used to facilitate the multiple passes of the ureteroscope and the removal of the polyps and stones from the proximal ureter. All 10 polyps were removed from the proximal portion of a single ureter. The ureteral stent was removed at 6 weeks, and follow-up intravenous urography at 6 months and ureteroscopy at 11 months showed no residual polyps or stones. The wall of the ureter was well healed, with no evidence of stricture. CONCLUSIONS: We have demonstrated a specific minimally invasive technique that can be used to treat even highly complex cases involving upper urinary tract fibroepithelial polyps.

Aged↗

PubMed2006

Combining hand assisted laparoscopic nephroureterectomy with cystoscopic circumferential excision of the distal ureter without primary closure of the bladder cuff--is it safe?

PURPOSE: We have previously described our technique of combining HAL-NU using early ureteral ligation with simultaneous cystoscopic circumferential excision of the distal intramural ureter without primary closure of the bladder cuff. We report the oncological sequelae in patients who underwent HAL-NU using our technique of complete ureteral removal. MATERIALS AND METHODS: We retrospectively evaluated all patients who underwent HAL-NU from April 1999 through July 2004. Cystograms were performed 1 week postoperatively in all patients. Pathological findings were reviewed. Cystoscopy was performed every 3 months to assess bladder recurrences. Upper tract imaging was performed postoperatively and then annually. The locations of recurrence and need for adjuvant treatment were assessed. RESULTS: A total of 49 patients with an average age of 67 years underwent HAL-NU. Gravity cystography confirmed that bladder defects had completely sealed at 1 week in all patients. Mean followup was 10.6 months (median 10, range 1 to 52). Of the patients 20 (49%) had bladder tumors postoperatively. Two patients were found to have advanced stage disease, leading to chemotherapy with radiation therapy in 1 and radical cystectomy in the other at 4 and 14 months, respectively. A total of 25 patients had postoperative pelvic imaging. Four patients with pathological stage T2 (1) and T3 (3) had metastatic disease at followup. One patient was known to have pulmonary metastases preoperatively and HAL-NU was performed for refractory hematuria. Two patients were noted to have distant metastases to the liver, lung and bone at 1 and 3 months postoperatively, respectively. One patient was found to have distant metastases to the liver and retroperitoneal lymph nodes 2 years after surgery. No patients were found to have local pelvic or peritoneal metastases. CONCLUSIONS: HAL-NU with cystoscopic excision of the distal ureter is feasible, safe and effective for upper tract transitional cell carcinoma. Oncological sequelae are comparable to results after open surgery. There is no evidence to suggest pelvic or peritoneal tumor seeding since no cases of pelvic or abdominal recurrence were discovered after surgery, while allowing the bladder defect to close spontaneously with catheter drainage. Our technique of ureterectomy ensures complete removal of the entire ureter, eliminating the possibility of ureteral stump recurrences. Early ligation of the ureter prevents tumor migration during renal manipulation, minimizing the risk of local tumor recurrences postoperatively.

Adult↗

PubMed2005

Correlation of preoperative three-dimensional magnetic resonance angiography with intraoperative findings in laparoscopic renal surgery.

BACKGROUND AND PURPOSE: Contrast-enhanced three-dimensional magnetic resonance angiography (3D-MRA) with image reconstruction has important applications in laparoscopic urologic surgery. We now use 3D-MRA as part of our preoperative evaluation in selected patients undergoing laparoscopic donor nephrectomy, pyeloplasty, radical nephrectomy, and partial nephrectomy. PATIENTS AND METHODS: From June 2001 to December 2002, 50 patients underwent preoperative 3D-MRA at 1.5 T prior to laparoscopic renal surgery. In general, preoperative 3D-MRA was obtained for donor nephrectomies and pyeloplasties and for cases where prior imaging suggested a possible vascular anomaly. Patients who underwent preoperative imaging included those having donor nephrectomy (N = 28), pyeloplasty (N = 12), radical nephrectomy (N = 5), partial nephrectomy (N = 3), and other laparoscopic renal procedures (N = 2). The 3D-MRA studies were interpreted by one radiologist, and all laparoscopic cases were performed by one of two surgeons. The findings of 3D-MRA were correlated with the intraoperative findings with special attention to aberrant vasculature, including duplicated renal arteries or veins, accessory vessels, or crossing vessels. RESULTS: Among patients undergoing laparoscopic donor nephrectomy, 3D-MRA correctly predicted the number of renal vessels in 27 of 28 cases (96%), including all 3 cases of left retroaortic renal vein. Also, 3DMRA correctly predicted the presence or absence of a crossing vessel in 10 of 12 cases (83%) of laparoscopic pyeloplasty. The imaging study also correctly predicted the number of hilar vessels in all five cases of radical nephrectomy, all three cases of partial nephrectomy, and both cases of other renal operations. Overall, 3D-MRA correctly defined the renal hilar anatomy in 48 of 50 patients, for an overall accuracy of 96%. CONCLUSIONS: Three-dimensional MRA findings correlate well (96%) with intraoperative findings in laparoscopic renal surgery. The imaging study provides exquisite vascular detail and is highly accurate, making it sufficient imaging prior to laparoscopic donor nephrectomy and useful for pyeloplasty and other complex renal operations.

Chelating Agents↗

PubMed2005

Computer-assisted laparoscopic pyeloplasty: University of Miami experience with the daVinci Surgical System.

PURPOSE: We report our experience with laparoscopic pyeloplasty using the daVinci surgical platform. PATIENTS AND METHODS: We routinely performed laparoscopic pyeloplasties prior to acquiring the daVinci system. We prospectively evaluated 26 computer-assisted laparoscopic pyeloplasties (CLP) performed since acquiring the device in March 2003. There were 15 male and 11 female patients with a mean age of 34.5 years, who underwent right-sided procedures in 11 cases and left-sided procedures in 15 cases. Four patients (15%) had secondary ureteropelvic junction obstruction. All procedures were performed through a transperitoneal approach over stents placed preoperatively. The operative time excluded the time needed for stent insertion. Radiographic objective success was defined as adequate cortical drainage (t (1/2) < or =15 minutes) and preserved or improved renal function on MAG-3 diuretic renography. RESULTS: A total of 23 dismembered pyeloplasties and 3 Y-V plasties were performed. In five patients, nephroscopy was performed for stone removal. The mean operative time and blood loss were 245 minutes and 69 mL, respectively. There were no intraoperative complications or open conversions. Three minor postoperative complications were noted. The mean length of hospital stay was 2 days (range 1-5 days). In 19 evaluable patients, at a median follow-up of 6 months (range 2-10 days), 15 (79%) had complete symptom resolution, while 3 (16%) had marked symptom improvement. The overall subjective improvement rate thus was 95%. The objective success rate based on our strict diuretic renography criteria was 100%. The overall clinical success rate was 95% (18/19). CONCLUSIONS: Robot-assisted laparoscopic pyeloplasty is a feasible alternative to laparoscopic or open pyeloplasty with excellent short-term subjective and objective success rates.

Adolescent↗

PubMed2004

Hand-assisted laparoscopic right donor nephrectomy: surgical technique.

Many centers have adopted laparoscopic and hand-assisted laparoscopic (HAL) techniques for live donor nephrectomy. Currently, the majority of laparoscopic living donor kidneys are procured from the left side because of the longer renal vein and improved transplantation. However, indications exist for right donor nephrectomy. We present our technique of HAL right-sided donor nephrectomy. A key feature of our dissection is wide mobilization of adjacent structures to achieve good exposure of the right kidney and inferior vena cava. In addition, the use of the hand permits optimal positioning of the kidney for division of the renal vessels with the vascular stapler. At the time of division of the renal vein, the stapler is placed on the wall of the inferior vena cava in order to gain maximal length. This technique has allowed HAL right-sided donor nephrectomy to be performed safely when indicated.

Humans↗

PubMed2004

Use of bipolar energy for transurethral resection of bladder tumors: pathologic considerations.

BACKGROUND AND PURPOSE: Bipolar electrocautery has recently been introduced as a modality for transurethral resection of bladder tumors (TURBT). The primary benefits of bipolar TURBT stem from the use of saline irrigant rather than glycine or water. TURBT should be conducted in a fashion such that the resected tissue can be used for proper grading and staging, so excessive cauterization of the tissue should be avoided. In this study, we compared the pathologic characteristics of bladder tumor specimens resected with bipolar versus standard monopolar energy to determine specimen quality. PATIENTS AND METHODS: Bipolar TURBT (Gyrus Medical Inc., Maple Grove, MN) was performed in 11 patients. Pathologic specimens were compared with the specimens from 11 patients who had previously undergone standard monopolar TURBT. Resected tissue was examined by a pathologist who recorded tumor size, grade, location, presence of muscularis propria, presence of muscle invasion, and final diagnosis. The pathologist also determined the degree of cautery artifact in each specimen. The pathologist was blinded to the form of electrocautery used and the clinical diagnosis. RESULTS: Transurethral resection with bipolar electrocautery was carried out without difficulty or complication in all cases. Similarly, there were no complications in resection by standard monopolar electrocautery. The bladder tumor chips obtained with bipolar TURBT were smaller because of the smaller size of the bipolar loop. However, this did not interfere with the pathologic assessment. There were no significant pathologic differences between specimens according to the type of cautery used. A large degree of cautery artifact was noted in the tissue of larger tumors resected using both monopolar and bipolar electrocautery. However, the incidence and degree of cautery artifact were similar in the two groups. No trends between tumor location and degree of cautery effect were noted. The pathologist had no difficulty reaching a full and proper diagnosis in all cases involving either form of electrocautery. CONCLUSIONS: Bipolar electrocautery is well suited for TURBT. Bladder tissue obtained from bipolar TURBT is of the same histologic quality as that obtained from standard monopolar TURBT and provides the urologist with a reliable and complete diagnosis.

Electrosurgery↗

PubMed2004

Laparoscopic upper pole heminephrectomy for ectopic ureter: initial experience.

OBJECTIVES: To determine the feasibility, clinical outcomes, and complications of laparoscopic upper pole heminephrectomy for ectopic ureter. The standard treatment for a duplex kidney with a poorly functioning upper pole moiety is an upper pole heminephrectomy. We review our technique and experience with laparoscopic upper pole heminephrectomy. A brief review of the literature is provided. METHODS: A retrospective review of clinical records from three patients who underwent laparoscopic upper pole heminephrectomy was performed. Two of the three patients presented with lifelong urinary incontinence and were diagnosed with an ectopic ureter associated with a poorly functioning upper pole moiety. The third patient presented with recurrent episodes of pyelonephritis and was found to have a duplex kidney with a poorly functioning upper pole segment draining into a ureterocele. RESULTS: All three patients underwent laparoscopic upper pole heminephrectomy through the transperitoneal approach. Mean operative time, including ureteral stent insertion, was 198 minutes. Two of the three patients were discharged within 24 hours of surgery. The third patient had a urinary leak secondary to a small amount of residual upper pole parenchyma which resolved with superselective renal arterial embolization. All three patients are well at 5.3 months follow-up. CONCLUSIONS: Laparoscopic upper pole heminephrectomy for ectopic ureter is safe and reproducible and offers the patient the typical postoperative benefits of laparoscopic surgery.

Adolescent↗

PubMed2003

Practice patterns in the treatment of large renal stones.

PURPOSE: To determine the current practice patterns of a large group of urologists in the treatment of large renal stones. MATERIALS AND METHODS: A survey was sent to all actively practicing members of the North Central Section of the American Urological Association. The questions pertained to age, time in practice, type of practice, time devoted to treating stones, residency training, case scenarios with treatment options, and whether they or a radiologist performed percutaneous access. The data were statistically analyzed. RESULTS: The response rate was 51% (564/1102 surveys returned). Three quarters (73%) of the urologists were comfortable performing percutaneous nephrolithotomy (PCNL), and 35% gave reasons they do not perform PCNL. Only 11% of those performing PCNL routinely obtained the percutaneous access themselves. Trends in the analysis included: (1) those trained to perform PCNL during residency were more often comfortable with this procedure; (2) younger urologists were more comfortable performing PCNL, even if they had been in practice for only a short time; (3) urologists in private practice were nearly as comfortable performing PCNL as were academic urologists; (4) urologists not comfortable with PCNL more often recommended SWL over PCNL as a primary treatment for moderate/large renal stones; and (5) few urologists routinely obtained percutaneous access themselves. CONCLUSIONS: Many urologists trained in recent years are comfortable performing PCNL. The type of training received influences treatment recommendations, and percutaneous access is most often obtained by/in conjunction with radiologists. This information may be useful in guiding residency training programs in the preparation of residents for the treatment of large renal stones.

Adult↗

PubMed2003

Laparoscopic upper-pole heminephrectomy for ectopic ureter: surgical technique.

A duplex kidney associated with a poorly functioning upper-pole segment is commonly associated with incontinence, voiding dysfunction, and urinary tract infections. A standard treatment option for this condition is upper-pole heminephrectomy. With the continued development of minimally invasive urology, this technique can now be safely performed laparoscopically. This report details step by step our technique of laparoscopic upper-pole heminephrectomy. Key points include placement of a catheter in the normal ureter at the start of the case, full mobilization of the upper-pole ureter away from the renal hilum, and precise identification of the vasculature supplying the upper pole. Laparoscopic upper-pole heminephrectomy for ectopic ureter is safe and reproducible and offers the patient the typical postoperative benefits of laparoscopic surgery.

Humans↗

PubMed2003

Leukocytospermia in spinal cord injured patients is not related to histological inflammatory changes in the prostate.

PURPOSE: Patients with spinal cord injuries have abnormal seminal plasma, which contributes to impaired sperm motility and viability. A common finding in these patients is an elevated leukocyte count in semen. We examined the prostatic tissue of spinal cord injured patients vs young healthy controls to determine whether a pathological process related to the prostate gland is a possible source of leukocytospermia. MATERIALS AND METHODS: Seven men with a mean age of 26.1 years with spinal cord injury and 4 controls with a mean age of 35.0 years underwent standard transrectal ultrasound guided prostate biopsy. Semen analyses were performed prior to biopsies. At least 3 biopsy cores were obtained from each prostate and all underwent routine hematoxylin and eosin staining. RESULTS: No significant abnormalities were found in any prostate biopsy cores. Two spinal cord injured patients had minor evidence of prostatic inflammation in 1 core. No inflammation was seen in any control specimens. None of the specimens showed signs of malignancy. CONCLUSIONS: Prostate biopsies obtained in this study did not show any signs of a chronic or acute significant inflammatory process that could explain increased leukocytospermia seen in patients with spinal cord injury.

Adult↗

PubMed2002

Identification and dissection of bladder neck during laparoscopic radical prostatectomy.

Bladder neck identification and dissection is a difficult step in performing laparoscopic radical prostatectomy. We describe a transurethral technique that facilitates laparoscopic identification and incision of the bladder neck. All cases were successful, with clear and sharp bladder neck margins. All bladder neck surgical margins were tumor free.

Electrocoagulation↗

PubMed2002

A comparison of unenhanced helical computerized tomography findings and renal obstruction determined by furosemide 99m technetium mercaptoacetyltriglycine diuretic scintirenography for patients with acute renal colic.

PURPOSE: We assessed unenhanced helical computerized tomography (CT) secondary findings as predictors of renal obstruction as determined by diuretic scintirenography, and determined their reproducibility. MATERIALS AND METHODS: We performed a retrospective review of the records of 77 consecutive patients with unenhanced helical CT findings (stones and secondary findings, including renal parenchymal edema, hydronephrosis, hydroureter, perinephric fat stranding, periureteral fat stranding and extravasation) of urinary lithiasis who had also undergone concomitant diuretic scintirenography during the initial emergency room evaluation during a 1-year period. Unenhanced helical CT films were independently reviewed by 2 attending radiologists (blinded to clinical outcome) to determine interobserver variability. The results were compared to those of diuretic scintirenography. RESULTS: Considerable interobserver variability, as evidenced by kappa values ranging from 0.26 to 0.60, existed for the diagnosis of secondary findings associated with urinary lithiasis on unenhanced helical CT. There was no significant difference in terms of CT findings between patients diagnosed by diuretic scintirenography as having high grade/complete obstruction and those with partial obstruction (p values 0.24 to 0.85 for the 6 unenhanced helical CT findings analyzed). Analyses of variance followed by Tukey's pairwise comparisons showed no significant difference in average number of unenhanced helical CT findings between patients with high grade/complete obstruction (mean plus or minus standard deviation 4.4 +/- 1.31), partial obstruction (4.4 +/- 1.30), and decompression/no obstruction (4.2 +/- 1.16). However, the mean number of unenhanced helical CT findings for patients with normal scintirenography/no obstruction (1.9 +/- 1.41) was significantly different from each of the other 3 diuretic scintirenography groups. Separate logistic regression analyses showed that each unenhanced helical CT finding, except for renal parenchymal edema and urinary extravasation, was a significant predictor of "any degree of obstruction" (high grade and partial obstruction groups) compared to "no obstruction" (decompressed and no obstruction groups). Odds ratios (95% confidence interval) ranged from 6.15 (2.25, 16.82) for perinephric fat stranding to 3.41 (1.30, 8.97) for hydroureter. When these analyses were repeated after exclusion of 8 patients with bladder/passed stones, only perinephric fat stranding and periureteral fat stranding remained significant predictors of "any degree of obstruction," with respective odds ratios of 4.21 (1.49, 11.91) and 4.08 (1.31, 12.65). CONCLUSIONS: Measures of agreement between trained, independent radiologists with respect to unenhanced helical CT secondary findings show considerable variability. The average number of CT consensus findings is not helpful in differentiating patients with variable degrees of obstruction, except for those with normal scintirenography/no obstruction. Unenhanced helical CT findings, except for renal parenchymal edema and urinary extravasation, are significant predictors of "any degree of obstruction" (high grade or partial obstruction) compared to "no obstruction" (decompressed or no obstruction). Therefore, unenhanced helical CT findings may be useful for identifying patients with any degree of obstruction but do not differentiate between those with high grade and partial obstruction.

Acute Disease↗

PubMed2002

Removal of bladder stone with metal wire infrastructure.

There are reports of a wide variety of foreign materials, placed purposefully or inadvertantly, that have been found in the lower urinary tract. Due to encrustatation, some of these objects may initially appear to be simple stones. A careful evaluation with an appropriate index of suspicion is needed to aid in the determination of whether one of these complex structures may be present. A determination of the composition of the structure will allow the surgeon to employ the most safe and expeditious means of removal. We report a case of a large bladder stone with a metal wire infrastructure that was removed by open cystolithotomy

Adult↗