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Carlos Uribe

Publications and source records attributed to Carlos Uribe.

5 recordsLinked to original sources
PubMed2005

Third Prize: Comparison of radical nephrectomy, laparoscopic microwave thermotherapy, cryotherapy, and radiofrequency ablation for destruction of experimental VX-2 renal tumors in rabbits.

BACKGROUND AND PURPOSE: Currently available minimally invasive renal tumor-ablation procedures include cryotherapy, radiofrequency ablation, and microwave thermotherapy. In this study, we investigated the ability of these three approaches to destroy experimental renal tumors in rabbits. The mechanism of potential tumor metastasis was also explored. MATERIALS AND METHODS: The VX-2 tumor line is an aggressive rabbit epidermoid tumor with a high metastatic potential. An initial experiment comparing cooled-tip microwave thermotherapy with cryotherapy and radical nephrectomy for treatment of small VX-2 tumors revealed that all microwave-treated rabbits had local recurrence and that several also had diffuse intraperitoneal carcinomatosis. In view of these results, a second experiment was performed in which 45 New Zealand White rabbits were implanted laparoscopically with VX-2 xenografts underneath the kidney capsule and divided into five groups of 9 each. The test groups were microwave thermotherapy with a 3.5-mm cooled-tip probe, microwave thermotherapy with a 3.5-mm noncooled- tip probe, radiofrequency ablation with a 1.5-mm cooled-tip probe, radiofrequency ablation with a 1.5- mm non-cooled tip probe, and cryotherapy with a 2.3-mm cryoprobe. The control groups were five rabbits that were not treated, five rabbits with tumors that had the tumor pierced with a probe but were untreated, and five rabbits that underwent nephrectomy after piercing of the tumor. Treatment was initiated 5 days after tumor implantation. One month later, all animals were euthanized and autopsied. RESULTS: At 5 days after tumor implantation, laparoscopic inspection revealed no visible peritoneal metastases. At 1 month, in the cooled and non-cooled microwave-thermotherapy groups, carcinomatosis occurred in five and six of nine animals, respectively. In comparison, carcinomatosis was detected in two of nine animals in the cryotherapy group at autopsy. With respect to cooled and non-cooled radiofrequency ablation, carcinomatosis was observed in four of nine rabbits in each group. In the control groups, none of the animals with unpierced tumors exhibited carcinomatosis, while carcinomatosis was seen in two of the five rabbits with tumor violated by piercing and in three of the five rabbits that underwent immediate nephrectomy after piercing of the tumor. CONCLUSION: Carcinomatosis occurred most frequently in animals treated with microwave thermotherapy, followed by radiofrequency ablation, and lastly cryoablation. The simple act of piercing a highly aggressive tumor can result in local spread. More disconcerting, and less well understood, is why certain ablative modalities appear to increase the rate of intraperitoneal spread.

Animals↗
PubMed2005

Effect of urine specific gravity on effectiveness of shockwave lithotripsy.

PURPOSE: To determine the effect of urine specific gravity (SG) and radiographic contrast medium on the efficiency of extracorporeal shockwave lithotripsy (SWL) fragmentation using a previously published in vitro model. MATERIALS AND METHODS: Artificial kidney stones (BegoStone [BEGO USA, Smithfield, RI]) of a standard size (10 x 10 mm) and weight (mean 1.90 g; range 1.89-1.91 g) were randomly allotted to one of four test media with differing SG: group 1: synthetic urine, SG 1.003; group 2: synthetic urine, SG 1.040; group 3: 50% radiographic contrast (Cysto-Conray II, Mallinckrodt Inc., Hazelwood, MO), 50% synthetic urine, SG 1.069; and group 4: 100% contrast, SG 1.121. The stones were placed in cups made of 2.2-mm screen mesh and exposed to 500 shockwaves at 20 KV from a spark-gap lithotripter (Econolith 2000; Medispec, Germantown, MD). The stone fragmentation rate (i.e., percent fragmentation) was determined by dividing the dry residual stone weight by the prelithotripsy dry weight (X 100). RESULTS: The mean fragmentation rate for the four groups was 31.7%, 37.6%, 31.8%, and 27.2%, respectively. Statistical significance was not achieved (P = 0.1). CONCLUSION: Stone breakage tends to be more effective when urine SG is about 1.040 than at higher or lower values. Hence, the recommendation for an overnight fast prior to SWL is well founded. Introduction of contrast medium may inhibit stone breakage because it increases the specific gravity.

Humans↗
PubMed2004

Sealing percutaneous nephrolithotomy tracts with gelatin matrix hemostatic sealant: initial clinical use.

PURPOSE: Tubeless percutaneous nephrolithotomy (PCNL) has been performed at several centers with good success. However, these cases have been carefully selected with regard to short duration and smaller stone burden to prevent complications associated with the loss of access to the collecting system. We describe the use of gelatin matrix hemostatic sealant (FloSeal Baxter Medical, Fremont, California) as an adjunct to tubeless percutaneous nephrolithotomy to help preclude bleeding complications. MATERIALS AND METHODS: Two patients were treated with PCNL through a single nephrostomy tract. At the satisfactory conclusion of the cases the tract was occluded retrograde with an occlusion balloon catheter and gelatin matrix hemostatic sealant was injected down the nephrostomy tract. An indwelling stent and bladder catheter were placed following which all guidewires were removed and skin sutures were placed. RESULTS: The operative times were 75 and 180 minutes, respectively. Both patients had stable postoperative hemoglobin and no evidence of bleeding or obstruction on postoperative computerized tomography. CONCLUSIONS: Injection of gelatin matrix hemostatic sealant into the nephrostomy tract may be of value in preventing bleeding after PCNL. In this pilot experience it provided immediate and effective hemostasis.

Female↗
PubMedDate not supplied

Current trends in urologic laparoscopic surgery.

PURPOSE: We examined the status of laparoscopy in urology and the impact of residency and fellowship training on the performance of laparoscopy as primary surgeon. We also examined whether performing nonsurgical tasks requiring two-handed dexterity had any link to the adoption of laparoscopic techniques by urologists. MATERIALS AND METHODS: A total of 8760 laparoscopy questionnaires containing 135 queries were mailed to urologists listed on the American Urological Association practicing urologists mailing list. The questions sought information on area of practice, time in practice, fellowship training, ambidexterity, laparoscopic experience, and experience with robotics. The response rate was 1.8% (155 of 8760). RESULTS: There appeared to be no significant correlation between the performance of laparoscopic surgery and participation in activities requiring bimanual dexterity. However, a correlation of strong statistical significance did exist between laparoscopic residency training and performance of laparoscopy after residency (p=0.003. There also was a correlation between fellowship training in laparoscopy/endourology and doing laparoscopy as primary surgeon. CONCLUSIONS: Participation in laparoscopic surgery during residency training is a major determining factor in performance of laparoscopy as a primary surgeon in practice. Younger surgeons trained in laparoscopy during residency are performing more laparoscopy post residency than those without laparoscopic training during residency. At present, there is a need to train more urologists in laparoscopy at the postgraduate level.

Adult↗