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Biomedical subjects

F C Delvecchio

Publications and source records attributed to F C Delvecchio.

16 recordsLinked to original sources
PubMed2001

Telemedicine: recent developments and future applications.

Telemedicine, or the delivery of health care from a distance, is an exciting field that has undergone rapid advancements over the past three decades. Previous studies have demonstrated that telemedicine can effectively assist in patient care. However, cost issues and the lack of resources to sustain telemedicine systems have previously limited the use of this technology. Herein, we explore the development, current applications, and future of telemedicine.

Analog-Digital Conversion↗
PubMed2001

Virtual reality: current urologic applications and future developments.

The concept of virtual reality (VR) involves the computer generation of environments with which a user can interact directly. Virtual reality is now being used for medical applications, especially in the area of surgical simulation. As technology advances, VR simulation will play an important training role for both residents and urologists already in practice. This paper examines the history of VR, current developments, and its future implications for the field of urology.

Computer Simulation↗
PubMed2001

Low-power holmium laser for the management of urinary tract calculi, structures, and tumors.

BACKGROUND AND PURPOSE: Introduction of the holmium laser has provided an indispensable tool for the management of urinary tract stones, strictures, and superficial urothelial tumors. While full-power holmium lasers are required for laser resection of the prostate, lower-power devices can be utilized for all cases of stone fragmentation and stricture incision and most cases of superficial urothelial tumors. Herein, we report our initial experience in utilizing a low-power holmium laser in our endourologic practice. PATIENTS AND METHODS: Over a 6-month period, we have utilized both low-power (25 W) and full-power (80 W) holmium lasers to fragment urinary tract stones, incise ureteral or urethral strictures, and ablate superficial urothelial tumors. A series of 80 consecutive patients were assessed prospectively. Laser fibers with a diameter of 200 microm and 365 microm were employed with power settings of 6.4 to 10 W. Laser fiber size and power settings were similar for the low- and full-power devices. RESULTS: Overall, 95% of the stones were completely fragmented, with a stone-free rate at 3 months of 92%. All strictures were incised, with a 91% patency rate at 3 months. Complete tumor ablation was attained in 70%, with a tumor-free rate of 60% at 3 months. Results were equivalent for the low- and full-power lasers. The 200-microm laser fiber allowed adequate access throughout the upper urinary tract during flexible ureteroscopy and flexible nephroscopy. The 365-microm laser fiber was employed via rigid and semirigid endoscopes. CONCLUSIONS: A low-power holmium laser supplies adequate fragmentation and incision power for virtually all endourologic cases. It also provides ablative power in most situations. The only current urologic application that cannot be performed with the low-power device is laser prostatic resection, which requires 60 to 80 W of power. The reduced-power holmium laser should be considered as a low-cost alternative for the management of urinary tract stones, strictures, and urothelial tumors, especially in centers where laser prostatic resection is not performed.

Adult↗
PubMed2001

Critical analysis of supracostal access for percutaneous renal surgery.

PURPOSE: Percutaneous renal surgery is currently performed for complex renal calculi as well as for various other endourological indications. In many patients an upper pole nephrostomy tract allows direct access to most of the intrarenal collecting system. Upper pole percutaneous access may be obtained via the supracostal or subcostal approach. The preferred route depends on the location and size of the specific stone or lesion. Previously others have cautioned against the supracostal approach above the 12th rib and many have discouraged an approach above the 11th rib due to concern about the increased risk of intrathoracic complications. We retrospectively assessed the morbidity associated with supracostal percutaneous renal surgery and compared and analyzed the morbidity of the supracostal and subcostal approaches. MATERIALS AND METHODS: The records of all patients who underwent upper pole percutaneous renal surgery between November 1993 and July 1999 were retrospectively reviewed. A total of 240 patients underwent percutaneous renal procedures, including 225 for managing symptomatic renal or ureteral stones, that is nonstaghorn calculi in 157, staghorn calculi in 41, proximal ureteral calculi in 12, calculi within a caliceal diverticulum in 6, calculi associated with primary ureteropelvic junction obstruction in 5 and calculi associated with a retained ureteral stent in 4. An additional 15 procedures were done for ureteropelvic junction obstruction (7), intrarenal collecting system tumors (5), a caliceal diverticulum without stones (1), a retained ureteral stent (1) and a ureteral stricture (1). RESULTS: A total of 300 nephrostomy tracts were placed to obtain access to the intrarenal collecting system via the supracostal approach in 98 (32.7%) cases and the subcostal approach in 202 (67.3%). Of the supracostal approaches 72 (73.5%) tracts were above the 12th and 26 (26.5%) were above the 11th rib. The overall complication rate irrespective of percutaneous approach was 8.3% (16.3% for supracostal and 4.5% for subcostal access). Complications included blood transfusion in 7 patients, intraoperative hemothorax/hydrothorax in 5, sepsis/bacteremia in 3, atrial fibrillation in 2, delayed nephropleural fistula in 2, renal artery pseudoaneurysm in 2, deep venous thrombosis/pulmonary embolus in 2, pneumothorax in 1 and subcapsular hematoma in 1. Seven of 8 intrathoracic complications (87.5%) developed in supracostal cases. CONCLUSIONS: Percutaneous renal surgery remains an important option for managing complex renal calculi and other upper urinary tract lesions. In our experience it is generally associated with low morbidity. The supracostal approach is often preferred for obtaining intrarenal access to complex renal and proximal ureteral pathology. Because supracostal access tracts are associated with significantly higher intrathoracic and overall complication rates compared to subcostal access tracts, this approach must be used with caution when no other alternatives are available.

Adolescent↗
PubMed2000

Nitinol stone retrieval-assisted ureteroscopic management of lower pole renal calculi.

OBJECTIVES: Current ureteroscopic intracorporeal lithotripsy devices and stone retrieval technology allow for the treatment of calculi located throughout the intrarenal collecting system. Difficulty accessing lower pole calculi, especially when the holmium laser fiber is used, is often encountered. We retrospectively reviewed our experience with cases in which lower pole renal calculi were ureteroscopically managed by holmium laser fragmentation, either in situ or by first displacing the stone into a less dependent position with the aid of a nitinol stone retrieval device. METHODS: Thirty-four patients (36 renal units) underwent ureteroscopic treatment of lower pole renal calculi between April 1998 and November 1999. Lower pole stones less than 20 mm were primarily treated by ureteroscopic means in patients who were obese, in patients who had a bleeding diathesis, in patients with stones resistant to shock wave lithotripsy, and in patients with complicated intrarenal anatomy, or as a salvage procedure after failed shock wave lithotripsy. Lower pole calculi were fragmented with a 200-micrometer holmium laser fiber by way of a 7.5F flexible ureteroscope. For those patients in whom the laser fiber reduced the ureteroscopic deflection, precluding re-entry into the lower pole calix, a 3.2F nitinol basket or a 2.6F nitinol grasper was used to displace the lower pole calculus into a more favorable position, allowing easier fragmentation. RESULTS: In 26 renal units, routine in situ holmium laser fragmentation was successfully performed. In the remaining 10 renal units, a nitinol device was passed into the lower pole, through the ureteroscope, for stone displacement. Only a minimal loss of deflection was seen. Irrigation was significantly reduced by the 3.2F nitinol basket, but improved with the use of the 2.6F nitinol grasper. This factor did not impede stone retrieval in any of the patients. At 3 months, 85% of patients were stone free by intravenous urography or computed tomography. CONCLUSIONS: Ureteroscopic management of lower pole calculi is a reasonable alternative to shock wave lithotripsy or percutaneous nephrolithotomy in patients with low-volume stone disease. If the stone cannot be fragmented in situ, nitinol basket or grasper retrieval, through a fully deflected ureteroscope, allows one to reposition the stone into a less dependent position, thus facilitating stone fragmentation.

Adult↗
PubMed2000

Microdialysis assessment of shock wave lithotripsy-induced renal injury.

OBJECTIVES: Shock wave lithotripsy (SWL) is the primary treatment modality for managing the majority of symptomatic renal calculi. However, the fundamental mechanisms for stone fragmentation and the resultant morphologic changes that occur are not fully understood. Furthermore, a thorough understanding of the complex biologic pathways involved in SWL-induced renal injury does not exist at present. To elucidate the biologic processes involved in tissue injury after SWL, an animal model was designed to mimic the pathogenesis of high-energy SWL in humans. METHODS: Juvenile female swine were anesthetized, and a midline laparotomy incision was performed to expose the right kidney. Using an introducer apparatus, a microdialysis probe was placed into the renal parenchyma of the right kidney lower pole and a tunnel was generated to exit the distal ends of the inlet and outlet tubing outside the body. After a 72-hour postoperative recovery period, SWL was performed to the lower pole renal region of the kidney, as a microdialysis pump continuously infused dialysate through the inlet tubing. Microdialysis fluids were collected during SWL, and lipid peroxidation, as measured by conjugated diene concentrations, was monitored. RESULTS: All microdialysis probes remained patent for a total of 2000 shock waves. A significant elevation in conjugated diene levels was observed in the SWL versus untreated kidneys after 1000 shock waves were administered (P <0.02). CONCLUSIONS: This animal model is unique in that it represents the first system for the real-time collection of renal interstitial fluids during SWL. Analysis of this fluid may provide insight into the physiologic mechanisms responsible for shock wave-induced renal injury.

Animals↗
PubMed2000

Renal surgery in the new millennium.

In the not too distant future, the minimally invasive renal surgeon will be able to practice an operation on a difficult case on a three-dimensional virtual reality simulator, providing all attributes of the real procedure. The patient's imaging studies will be imported into the simulator to better mimic particular anatomy. When confident enough of his or her skills, the surgeon will start operating on the patient using the same virtual reality simulator/telepresence surgery console system, which will permit the live surgery to be conducted by robots hundreds of miles away. The robots will manipulate miniature endoscopes or control minimally or noninvasive ablative technologies. Endoscopic/laparoscopic footage of the surgical procedure will be stored digitally in optical disks to be used later in telementoring of a surgery resident. All this and more will be possible in the not so distant third millennium.

Cryotherapy↗
PubMed2000

Management of residual stones.

Stone-free status is highly dependent on selection of the appropriate surgical technique, which should be tailored according to the individual stone and patient parameters. Although a stone-free state is the desired outcome of surgical intervention of urolithiasis, the authors believe that the presence of noninfection, nonobstructive, asymptomatic postprocedural residual fragments can be managed metabolically in order to prevent stone growth adequately. Further surgical intervention in the case of residual fragments is warranted if the clinical indications that prompted the original surgery persist.

Humans↗
PubMed2000

Combined antegrade and retrograde endoscopic approach for the management of urinary diversion-associated pathology.

BACKGROUND: Endourologic management of stones and strictures in patients with a urinary diversion is often cumbersome because of the absence of standard anatomic landmarks. We report on our technique of minimally invasive management of urinary diversion-associated pathology by means of a combined antegrade and retrograde approach. PATIENTS AND METHODS: Five patients with urinary diversion-associated pathology were treated at our institution between May 1997 and October 1998. Their problems were: an obstructing ureteral stone in a man with ureterosigmoidostomy performed for bladder extrophy; two men with a valve stricture in their hemiKock urinary diversions; an anastomotic stricture in a man with an ileal loop diversion; and a long left ureteroenteric stricture in a man with a right colon pouch diversion. After percutaneous placement of an guidewire across the area of interest, the targeted pathology was accessed via a retrograde approach using standard semirigid or flexible fiberoptic endoscopes. Postoperative follow-up with intravenous urography, differential renal scan, or both was performed at 3 to 24 months (mean 12 months). RESULTS: The combined antegrade and retrograde approach allowed successful access to pathologic areas in all patients. Holmium laser/Acucise incision of stenotic segments or ballistic fragmentation of stones was achieved in all cases without perioperative complications. None of the strictures with an initially successful outcome has recurred; however, in one patient, the procedure failed as soon as the internal stent was removed. The patient with the ureteral calculus remains stone free, and his ureterosigmoidostomy is patent without evidence of obstruction on his last imaging study, 24 months postoperatively. CONCLUSIONS: Combined antegrade and retrograde endoscopic access to the area of interest is our preferred method of approaching pathologic problems in patients with a urinary diversion. An antegrade nephrostogram provides better delineation of anatomy, while through-and-through access enables rapid and easier identification of stenotic segments that may be hidden by mucosal folds. Furthermore, this approach allows the use of larger semirigid or flexible endoscopes in conjunction with more efficient fragmentation devices, resulting in enhanced vision from better irrigation. Finally, an initial endoscopic approach may be preferred because its failure does not compromise the success of future open surgery.

Aged↗
PubMed2000

Successful management of lower-pole moiety ureteropelvic junction obstruction in a partially duplicated collecting system using minimally invasive retrograde endoscopic techniques.

Although the true incidence of ureteropelvic junction (UPJ) obstruction in the lower-pole moiety of an incompletely duplicated renal collecting system remains elusive, the description of this entity in the published literature is exceedingly rare. To our knowledge, we report the first case of this entity managed successfully by ureteroscopic holmium laser incision of the stenotic UPJ segment. This case underscores the utility of minimally invasive techniques in the management of selected cases of UPJ obstruction associated with a partially duplicated collecting system.

Humans↗
PubMed2000

Endoscopic management of urologic disease with the holmium laser.

The efficiency and safety profile of the holmium laser have made this tool a versatile multipurpose instrument for use in the endoscopic treatment of a wide variety of urologic disorders. Herein are reviewed holmium laser physics and current endourologic applications, as well as the performance of new low-power holmium lasers.

Endoscopy↗
PubMed2000

Clinical efficacy of combined lithoclast and lithovac stone removal during ureteroscopy.

PURPOSE: Pneumatic lithotripsy has proved to be an extremely safe, efficient and low cost intracorporeal fragmentation modality. Unfortunately proximal migration of fragments into inaccessible areas in the intrarenal collecting system is a potential limitation during ureteroscopic procedures. Moreover, the lack of an efficient mechanism of stone retrieval further limits the widespread application of this technique. The newly developed Lithovacdagger suction device was designed to be combined with pneumatic lithotripsy during ureteroscopic stone removal. We evaluated the effectiveness of this combination for overcoming these limitations. MATERIALS AND METHODS: Between February and December 1998, 21 patients underwent pneumatic lithotripsy of ureteral calculi combined with use of the Lithovac suction probe. Stone area was 20 to 320 mm.2 (mean 84). Of the stones 71% and 29% were in the distal, and proximal and/or mid ureter, respectively. We used a 0.8 mm. pneumatic lithotripsy probe placed through a 4.8Fr Lithovac probe at a pulse frequency of 12 Hz. and pressure of 2 atmospheres. RESULTS: Mean operative time was 42 minutes and the stone fragmentation rate was 100%. There were no complications in our series and no proximal migration of fragments. The overall stone-free rate was 95% at 3-month followup. CONCLUSIONS: Using the Lithovac suction device greatly facilitates pneumatic lithotripsy during ureteroscopic stone removal. This combination not only prevents fragment migration, but also aids in maintaining a clear endoscopic field of view, allowing efficient, safe and effective stone fragmentation.

Adolescent↗
PubMed1999

Use of a digital camera in the urologic setting.

Urologists are faced with increasing demands for clear documentation of their work. We report the use of a digital camera in our practice to capture images throughout the urologic setting. The digital camera was a quick and convenient means of obtaining good quality reproductions of radiographic and pathologic findings. Use of the camera greatly enhanced the efficiency of our practice by allowing incorporation of images into patient records and an image library.

Humans↗
PubMed1999

Digital still image recording during video endoscopy.

With the advances in telemedicine and virtual consultation services comes the need for state-of-the-art endoscopic imaging techniques and equipment. Concomitant with current day concerns of cost containment, the ability to utilize the aforementioned tools in a cost-effective fashion that lowers operating expenses, accurately depicts procedures, and expedites chart documentation is paramount. We report on a fast and efficient way to obtain and store images during endoscopic procedures, which can be stored on standard 3.5-inch floppy disks using an innovative digital image recorder. These images are stored as high-resolution (640x480x24) JPEG files, which can be placed in electronic medical records, imported into Internet Web pages, incorporated into slide presentations, and, most importantly, stored in easily accessed archives.

Computer Communication Networks↗
PubMed1999

Digital image recording: an integral aspect of video endoscopy.

In today's medical environment, efficiency and accuracy are the keys to successful outcomes. This concept is especially applicable during video endoscopic imaging, where image clarity is of utmost importance for medical applications. One of the most exciting advances in video endoscopy is the development of digital image storage devices. We report on a fast and efficient way to grab and store images during endoscopic procedures. Images can be stored on standard 3.5" floppy disks using an innovative new digital image recorder. The images are stored as high resolution JPEG files (640 x 480 x 24) for excellent clarity and detail. Once loaded onto the computer or network, the images can be placed into electronic medical records, imported into internet web pages, incorporated into slide presentations, and most importantly, stored in well organized archives which take up a minimum of space and are easily accessed by multiple users. This digital image recorder provides a complete system for acquiring images on a standard format 3.5" floppy disk--the world's most ubiquitous storage format.

Endoscopy↗