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Biomedical subjects

D Bagley

Publications and source records attributed to D Bagley.

14 recordsLinked to original sources
PubMed1995

The case for primary endoscopic management of upper urinary tract calculi: I. A critical review of 121 extracorporeal shock-wave lithotripsy failures.

OBJECTIVES: To define those patients with upper urinary tract calculi who are more likely to have an unsuccessful outcome from extracorporeal shock-wave lithotripsy (ESWL). METHODS: A critical prospective analysis of 121 patients, referred to two university centers after ESWL had been exhausted as a treatment modality for upper urinary tract calculi, was performed. Patients were subdivided into the following groups: failure to clear fragments, failure to fragment, difficulty in calculus localization, and failure due to inherent upper urinary tract obstruction. Other important variables include the type of extracorporeal lithotriptor used, number of treatment sittings before referral, calculus location, calculus composition, patient body habitus, and the imaging leading to and associated with extracorporeal therapy. RESULTS: Large renal calculi (mean, 22.2 mm) and those within dependent or obstructed portions of the collecting system were frequently referred for endoscopic management after failed ESWL. Steinstrasse can be an extremely morbid complication from ESWL and in this series was associated with irreversible loss of renal function and ureteral stricture disease. Extracorporeal lithotripsy of infectious calculi can be associated with severe septic complication. Inadequate preoperative and intraoperative imaging and morbid obesity were also associated with failure. Second- and third-generation lithotriptors were represented in greater numbers than the Dornier HM-3 in this group of ESWL failures. CONCLUSIONS: ESWL remains the treatment of choice for moderately sized, uncomplicated renal calculi. Large calculi, those within obstructed or dependent portions of the collecting system, and those composed of calcium oxalate monohydrate, frequently fail ESWL. Training in the more technically challenging aspects of endoscopic lithotripsy must be encouraged.

Adolescent↗
PubMed1995

Endoscopic management of the symptomatic caliceal diverticular calculus.

Caliceal diverticular calculi are most often asymptomatic and of little clinical significance. In certain cases they may be associated with flank pain, pyuria and chronic urinary tract infections. Treatment has evolved from open surgical techniques to a purely endoscopic approach. Percutaneous techniques are frequently used to address the diverticular stone burden and to dilate the diverticular neck, improving drainage. Small volume caliceal diverticular calculi and those in the anterior portion of the collecting system represent a greater technical challenge to the endoscopist. We describe a purely retrograde endoscopic technique for treating small stone burdens trapped in caliceal diverticula. Flexible ureteroscopy combined with 3F dilating balloons passed through the endoscopic working channel facilitated treatment. This retrograde technique was combined with a simultaneous primary percutaneous puncture into the diverticulum to treat larger stone burdens and calculi within long-necked diverticula. This combination facilitated prompt, through and through access of a percutaneously placed guide wire, increasing the overall efficiency of treatment. In conclusion, a retrograde endoscopic technique using the actively deflectable, flexible ureteroscope can successfully treat certain caliceal diverticular calculi. By combining this technique with a simultaneous percutaneous puncture, caliceal diverticular calculi throughout the collecting system may be cleared expeditiously.

Diverticulum↗
PubMed1994

A 7.5/8.2 F actively deflectable, flexible ureteroscope: a new device for both diagnostic and therapeutic upper urinary tract endoscopy.

OBJECTIVE: To develop and employ in a prospective fashion a small-diameter, actively deflectable, flexible ureteroscope that could be easily placed into the upper urinary tract and would increase the overall therapeutic potential for this class of endoscope. METHODS: A small-diameter, actively deflectable flexible ureteroscope was recently employed in clinical trials at two university centers. Improvements in fiberoptic engineering allowed endoscope miniaturization (7.5 F tip and 8.2 F shaft) while maintaining a relatively large (3.6 F) centrally located working channel. A variety of design modifications were employed through various prototype stages. Mechanical parameters included maximizing two-way active deflection, adequate secondary deflection allowing access to the lower pole caliceal system, and maintaining a sturdy (nonbuckling) durometer. RESULTS: The 7.5 F flexible ureteroscope was employed in sixty-seven procedures (64 patients). Therapeutic rather than purely diagnostic maneuvers made up the majority of procedures. Thirty-one upper ureteral, renal pelvic, or caliceal calculi were treated with a variety of endoscopic lithotriptors placed through the ureteroscope. Six patients underwent both biopsy and endoscopic treatment of superficial papillary transitional cell malignancies. Retrograde endopyelotomy, incision or dilation of ureteral strictures, extraction of renal pelvic foreign bodies, and endoscopic access and treatment of obstructed caliceal diverticula were other applications. Endoscopic access to the upper urinary tract rarely required active intramural ureteral dilation (14%). Excluding patients with prior ureteral stents or those who underwent rigid distal third ureteral endoscopy prior to flexible proximal ureteroscopy, 31 patients (48%) required no intramural ureteral dilation prior to placing the endoscope. CONCLUSIONS: The increased therapeutic potential observed with the 7.5 F actively deflectable, flexible ureteroscope opens a variety of upper urinary tract pathologic states to minimally invasive (endoscopic) treatments.

Adolescent↗
PubMed1994

Treatment of urinary calculi in a porcine and canine model using the Browne Pneumatic Impactor.

OBJECTIVES: To define the safety and efficacy of a pneumatically driven, mechanical lithotriptor using nitinol probes through semirigid and actively deflectable, flexible fiberoptic endoscopes. METHODS: The Browne Pneumatic Impactor (BPI) uses standard compressed air to drive a nitinol wire along its long axis onto a calculus, fragmenting it. Bench top and in vivo experiments were designed to explore variables, including the effects of various nitinol probe tip designs, outer diameters, excursion distances, and sheathing materials as well as the efficiency of fragmentation with active endoscope deflection. In vivo experiments in two animal models (porcine and canine) were performed using small diameter, fiberoptic semirigid, and actively deflectable, flexible ureteroscopes. Surgically placed calculi were fragmented with the BPI and representative tissue was obtained immediately and up to 2 weeks postoperatively to define histologic changes. A panel of human urinary calculi was chosen for their relative difficulty in fragmentation with other modalities. RESULTS: Calculi, including pure calcium oxalate monohydrate, brushite, cystine, and triamterene, were fragmented with the BPI used through both semirigid and actively deflectable, flexible endoscopes. A rounded tip design and excursions of 1 mm fragmented calculi most efficiently with minimal histologic reaction. Retrograde stone migration before fragmentation was noted in dilated upper urinary tracts. This was prevented by first entrapping the calculus within a standard basket. Ureteral calculi were fragmented with the nitinol probes deflected up to 45 degrees by the flexible endoscope. With increased active deflection, the efficiency of fragmentation decreased. CONCLUSIONS: The BPI represents a safe, thermal-free endoscopic lithotrite able to fragment the hardest calculi through semirigid and flexible ureteroscopes.

Alloys↗
PubMed1994

Prospective comparison of external sphincter prosthesis placement and external sphincterotomy in men with spinal cord injury.

The effectiveness and complications of the treatment of detrusor-external sphincter dyssynergia (DESD) and voiding pressure > 60 mm H2O using an endoluminal urethral sphincter prosthesis (Urolume) were compared with those of conventional external sphincterotomy in 46 men with spinal cord injury (SCI) (mean age 34 years; range 18-58 years). Twenty-six patients elected the Urolume, and 20 chose sphincterotomy. The age and level and duration of SCI were similar in the two groups. Follow-up ranged from 6 to 20 months. After prosthesis placement, voiding pressure dropped from 88 +/- 29 cm H2O to 38 +/- 22 cm H2O at 6 months (n = 23) and 35 +/- 16 cm H2O at 12 months (n = 18) (P < 0.001). The residual urine volume fell from 180 +/- 145 mL preoperatively to 85 +/- 125 mL at 12 months (P < 0.001), while the maximum cystometric capacity remained constant (P = 0.75). External sphincterotomy achieved similar statistically significant decreases in voiding pressure and residual urine volume, and bladder capacity was maintained. The preoperative and follow-up urodynamic measures were similar in the two groups. Prosthesis placement was associated with a significantly shorter operation (P = 0.001) and length of hospitalization (P = 0.01), a lower hospitalization cost (P = 0.01), and less bleeding (change in hemoglobin concentration) (P = 0.01) than external sphincterotomy. The complications of stent insertion were device migration (n = 4) and secondary bladder neck obstruction (n = 2). One patient with continuing reflux required bilateral ureteral implantation. The complications of sphincterotomy were bleeding necessitating transfusion (n = 2), recurrent obstruction (n = 2), and erectile dysfunction (n = 1). The sphincter prosthesis is as effective as sphincterotomy in the treatment of DESD, while being technically easier, less morbid, and less expensive.

Adult↗
PubMed1993

Versatile uses for plunger attachments.

Plunger attachments are among the simplest of all attachments, yet they are extremely versatile. When basic design principles are followed, plunger attachments can be employed to solve diverse restorative situations.

Denture Design↗
PubMed1991

Endoluminal sonography of the urinary tract: preliminary observations.

Endoluminal sonography of the urinary tract was performed by using endoluminal ultrasound transducers contained within 2-mm-diameter catheters. The catheters were inserted into the urinary bladder via the urethra and advanced into the ureters and renal pelvis under cystoscopic control; then, cross-sectional images of the bladder, ureters, and renal pelvis were obtained. Two dogs and seven human patients were studied. In one dog, a 4.5-mm pseudopolyp, which was surgically created in the bladder wall, was successfully imaged; in the other, stones 2 mm or larger inserted into the bladder were identified. Of the seven patients, sonography showed stones embedded in the renal parenchyma (one patient) and the mucosa of the distal ureter (one patient). These were ultimately confirmed by their eventual removal. In a third, sonography showed a tumor of the distal ureter and identified the depth of the tumor. This was confirmed by biopsy. In a fourth, sonography clearly showed a crossing vessel as the cause for narrowing of the proximal ureter. In a fifth, sonography showed that the cause of a ureteral stricture was idiopathic. In the last two cases, sonography did not reveal a cause for hematuria. In these last three cases, negative sonographic results were confirmed by direct ureteroscopic examinations and follow-up studies. Our observations based on this limited study suggest that endoluminal sonography is a useful procedure for diagnosing diseases of the urinary tract. Further study is warranted.

Adult↗
PubMed1982

Appearance of a partial nephrogram with an absent kidney.

A case is reported of a 16-year-old female who sustained a gunshot wound to the left upper abdomen. Early opacification of a structure in the left upper quadrant on an excretory urogram was suggestive of a nephrogram. The left kidney was absent at operation. The diagnostic limitations of excretory urography in the trauma patient and the alternative diagnostic techniques, radionuclide scanning, arteriography, or tomography, or possibly operative intervention, are recommended. Although not found in our patients, a thorough search for an ectopic kidney should be made.

Abdominal Injuries↗
PubMed1980

Renal angiomyolipoma: diagnosis and management.

Renal angiomyolipoma is a benign tumor. Use of excretory urography, plain tomography, arteriography, ultrasound, and computerized tomography can usually provide the diagnosis. Appropriate operative or nonoperative management can then be determined for the individual patient.

Adult↗