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George A Barbalias

Publications and source records attributed to George A Barbalias.

15 recordsLinked to original sources
PubMed2006

Digital subtraction angiography and computer assisted image analysis for the evaluation of the antiangiogenetic effect of ionizing radiation on tumor angiogenesis.

PURPOSE: The aim of the present study was to evaluate and quantify the antiangiogenetic effect of ionizing radiation on tumor angiogenesis using digital subtraction angiography (DSA) in conjunction with computer assisted image analysis (CAIA). METHODS: Walker 256 carcinosarcoma was inoculated in both glutei of 12 Wistar rats. When the tumors reached a diameter of 1.5 cm, local irradiation of the right gluteus was performed. The left gluteus of each animal served as a control. After 24 hours of irradiation, angiography was performed, and images where digitized and subsequently processed. The effect of irradiation was observed both in big and small vessels (smaller or greater than 200 microm). RESULTS: Irradiated areas of both small and big vessels showed a statistically significant reduction in both total vessel area and length. Small vessels showed a greater trend toward suppression by irradiation (not statistically significant). CONCLUSION: Irradiation had a deleterious effect in both macro- and micro-blood supply of a tumor. The use of CAIA enhanced the efficacy of DSA and enabled the in vivo identification of the effect of irradiation on various caliber vessels as well as the ratios of total length and total area of small and big vessels.

Angiography, Digital Subtraction↗
PubMed2006

Case report: laparoscopic adrenalectomy in a patient with primary adrenal malignant melanoma.

We report a case of laparoscopic management of a primary malignant melanoma of the left adrenal gland. A 42-year-old male presented a 55 x 60-mm round, inhomogeneous, noninvasive mass of the left adrenal gland. Hormone-activity values were within normal range. The mass was removed laparoscopically en bloc along with the left adrenal gland, and its histopathologic evaluation was consistent with the features of a malignant melanocytic tumor. Postoperatively, the patient presented no signs of fever or remarkable blood loss and was discharged on the third day in good clinical condition. He is free of disease 1 year later.

Adrenal Gland Neoplasms↗
PubMed2005

Ureteral metal stents: a tale or a tool?

There are four types of ureteral metal stents: self expandable, balloon expandable, covered, and thermoexpandable shape-memory. Insertion of metal stents requires expertise with transurethral and percutaneous techniques. The stricture is traversed with the aid of a guidewire via a percutaneous nephrostomy, and the stenotic segment is dilated using a high-pressure balloon catheter. The stent is then inserted over the guidewire, such that the upper end bypasses the obstruction by at least 3 to 4 cm, while the lower end extends intravesically for 0.5 to 1 cm from the ureteral orifice. If necessary, two or more stents are placed in sequence, overlapping by at least 2 to 3 cm. Metal stents were initially used for the relief of end-stage malignant disease, and their role in the treatment of benign ureteral strictures is still undefined. Patients often complain of abdominal discomfort and mild pain after stent insertion, which soon resolve spontaneously. Hematuria usually stops after a few days and does not necessitate any treatment. Mild urothelial hyperplasia in the stent lumen is common but usually regresses after 4 to 6 weeks. Many authors suggest the use of a double-pigtail catheter for the first 4 to 6 weeks to avoid narrowing of the ureteral lumen. The influence of stents on ureteral peristalsis is a major but poorly documented issue. Encrustation is a significant problem that needs to be addressed. The characteristics of both the patient and the stent influence its likelihood. Migration of coated metal stents was seen in 81% of patients at our center. Virtual endoscopy has recently been introduced as a tool for the follow-up of patients with stented ureters. Further design development is necessary to obtain the ideal ureteral metal stent. In a recent study in female pigs, paclitaxel-eluting metal stents engendered less inflammation and hyperplasia of the surrounding tissues.

Aftercare↗
PubMed2004

Congenital seminal vesicle cyst and coexisting renal agenesis: laparoscopic approach.

We report a case of laparoscopic excision of a large symptomatic left seminal vesicle cyst and ipsilateral renal agenesis. A 26-year-old man presented with a 15-year history of dysuria and irritative voiding symptoms. The diagnostic evaluation revealed a 62 x 40 x 35-mm left seminal vesicle cyst. In addition, he had a solitary, right, functioning kidney, with no evidence of the left renal unit. Transperitoneal laparoscopic excision of the cyst was performed successfully. The total operative time was 190 minutes, and blood loss was minimal. The patient was discharged from the hospital on the second postoperative day and did not present with any complaints or complications thereafter.

Cysts↗
PubMed2004

Virtual endoscopy in renal artery stenosis: an innovative approach for diagnosis and follow-up.

PURPOSE: We investigated the utility of virtual endoscopy (VE) as a diagnostic and follow-up tool in patients with renal artery stenosis, especially as a means of defining vascular patency. PATIENTS AND METHODS: We performed VE in 24 patients with ostial atherosclerotic renal artery stenosis and correlated the results with those of conventional angiography. The patients were treated successfully by placement of metal stents and conventional catheter angiography and VE for patency assessment 6 and 12 months after stent insertion. RESULTS: In all patients, the stenotic segment was identified, and VE findings were concordant with those of angiography. The average degree of stenosis was estimated to be 70% +/- 20% when angiography was used and 62% +/- 15% when VE was used. After metal stent insertion, the 12-month patency rate was 83.3% (20 patients). Angiography and VE findings remained concordant during the follow-up period, but VE provided more information beyond the stenotic segment, allowing examination of the arterial lumen both cephalad and caudal to the point of obstruction. CONCLUSION: Virtual endoscopy provided a more dynamic, direct, minimally invasive approach that was equal to or better than angiography for both the verification of the vascular stenosis and the evaluation of the arterial lumen.

Aged↗
PubMed2004

Tele-diagnostic and therapeutic guidance in urology.

PURPOSE: To design a Web-based network for diagnostic and therapeutic guidance in urology. MATERIALS AND METHODS: We designed an architectural model of a low-cost multimedia Web platform that runs on a collection of distributed collaborative network nodes to provide a set of urologist-oriented Web-enabled services. Any node of the platform was able to share patient-oriented data via automated processes with appropriate authorization, confidentiality, and high-security protocols. The urologist can show the details of the records of patients and additionally enrich the world experience with his or her own cases. Video clips maintained locally at the nodes will be accessible by clinicians in a trouble-free way with MS Windows Media player and a relatively small amount of source code. RESULTS AND CONCLUSIONS: The primary advantage of this architectural model is that it provides Web-enabled integrated urologic services while using a distributed storage scheme for urological video files (AVI format) and a global repository of laboratory results using Extensible Markup Language (XML) and Data Grid technologies. In addition, this model provides decision-support services (knowledge from a global database and predefined procedures). The architecture model is based entirely on HTTP, XML, GRID-like environment and DotNet technologies. Finally, the platform provides extensibility and scalability targeted to large-scale Web-enabled global urologic databases.

Decision Support Techniques↗
PubMed2003

Ureteral metallic stents: application of virtual endoscopy for ureteral patency control.

OBJECTIVE: In the present study we have applied virtual endoscopy (VE) in patients with ureteral metallic stents as a follow-up tool study especially in the need to define ureteral patency. METHODS: We performed the suggested technique in 6 patients with malignant ureteral obstruction treated successfully by placement of Wallstent intraureteral metallic stents, and correlated the results with antegrade nephrostomography 48 hours after initial stent placement. RESULTS: In 2 patients restenosis was observed, and in the remaining 4 patients the stented ureters remained patent during the follow up evaluation. VE and antegrade nephrostomography, were concurrent as to their findings. Moreover, VE proceeds beyond the stenotic segment, allowing visualization of the ureteral lumen both cephalad and caudal to the point of obstruction. CONCLUSION: VE is providing indeed a more accurate, direct and dynamic approach in the evaluation of a strictured ureteral lumen within the metallic stent.

Female↗
PubMed2002

Ureteropelvic junction obstruction: an innovative approach combining metallic stenting and virtual endoscopy.

PURPOSE: We report our experience with auto-expandable metallic stents for treating ureteropelvic junction obstruction. MATERIALS AND METHODS: We treated 4 patients with a mean age of 45 years who had ureteropelvic junction obstruction with placement of a self-expandable intraureteral metallic stent (Wallstent, Schneider, Zurich, Switzerland). All patients presented with recurrent ureteropelvic junction obstruction after open pyeloplasty. Excretory urography and 3-dimensional reconstruction computerized tomography were performed 1 and 6 months after stent insertion. Virtual endoscopy images were obtained at followup due to the need to define ureteral patency. RESULTS: Mean followup was 16 months (range 9 to 24). Wallstent placement was successful and immediate patency was achieved in all cases. During followup 3 patients required no further intervention and the stented ureteropelvic junction remained patent. In the remaining patient stricture recurred 2 months after initial stent insertion due to the ingrowth of scar tissue through the prosthesis. Additional intervention was deemed necessary after placing a longer 6 cm., completely coaxial overlapping metal stent. Virtual endoscopy and excretory urography findings concurred. Virtual endoscopy allows visualization of the stented ureteropelvic junction lumen cephalad and caudal to the prosthesis. It also enables easy navigation within the stent at different angles of view. CONCLUSIONS: The concept of applying metallic stents for ureteropelvic junction obstruction and adjacent adynamic ureteral segments combined with virtual endoscopy is strengthened by the results of this study.

Adult↗
PubMed2002

Externally coated ureteral metallic stents: an unfavorable clinical experience.

OBJECTIVE: The purpose of the present study was to evaluate the use of externally coated stents in patients with malignant ureteral obstruction. MATERIALS AND METHODS: We have prospectively evaluated 16 patients, 10 men and 6 women, with malignant ureteral obstruction treated successfully by placement of Passager metal stents (Boston Scientific, Natick, MA, USA) bypassing the stricture. Mean patient age was 65.6 years (range 62-78 years). Ureteral patency was confirmed 24 and 48 hours by injection of contrast material through the nephrostomy tube, and after patency confirmation the nephrostomy catheter was removed. RESULTS: All stents were positioned successfully, and the postoperative course was uneventful. In 13 cases (81.2%) the prostheses finally migrated into the bladder hindering overall ureteral patency (mean time of migration: 1.5 months). Patency was achieved in the remaining ureters (n=3), during the follow-up period (mean: 8 months, range 6-16 months), without any need for further intervention. CONCLUSION: The inappropriate anchorage and the increased ureteral peristalsis are the main causes of migration towards the bladder, thus, minimizing the usefulness of this stent for the treatment of ureteral strictures.

Aged↗
PubMed2002

Delayed suture intravesical migration as a complication of a Stamey endoscopic bladder neck suspension.

We report our experience with two cases of late migration of the suture and bolster occurring 2 years after a modified Stamey endoscopic bladder neck suspension. Delayed migration of the suture and bolster after an endoscopic bladder neck suspension across tissue planes, with subsequent erosion into the bladder, is uncommon. Recurrent urinary tract infection and mild suprapubic discomfort were the only symptoms. Cystoscopy was the only helpful diagnostic tool and should be considered early in the evaluation of this kind of patients. The mechanism of migration of the cuff and the operative technique are discussed.

Cystoscopy↗
PubMedDate not supplied

Virtual endoscopy: navigation within pelvicaliceal system.

PURPOSE: To evaluate the use of virtual endoscopy (VE) for the investigation of the pelvicaliceal unit and the depiction of its anatomic deformities. PATIENTS AND METHODS: Two study groups were prospectively enrolled in our protocol: ten patients with nonurologic pathologies, and thus without any known deformity of the pelvicaliceal unit (group A), and five patients with caliceal obstruction (group B). Virtual endoscopy represented a non-invasive technique providing amplification of the image in three-dimensional space. RESULTS: Virtual endoscopy was feasible in all patients, and in all cases succeeded in demonstrating the threedimensional morphology of the region of interest. The entire processing time ranged from 10 to 15 minutes (mean 12.6 minutes), and the three-dimensional image could be viewed from different angles, allowing better evaluation of the collecting system and its deformities than is possible with conventional intravenous urography or percutaneous nephrostomography. CONCLUSION: Virtual endoscopy enabled the creation of endoluminal views of the renal pelvis and calices from spiral tomographic images, thereby allowing diagnostic-preoperative and postoperative evaluation of the pelvicaliceal unit.

Adult↗