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    Augmented Reality: A New Tool To Improve Surgical Accuracy during Laparoscopic Partial Nephrectomy? Preliminary In Vitro and In Vivo Results
    (Elsevier, 2009) Teber, Dogu; Guven, Selcuk; Simpfendoerfer, Tobias; Baumhauer, Mathias; Gueven, Esref Oguz; Yencilek, Faruk; Goezen, Ali Serdar
    Background: Use of an augmented reality (AR)-based soft tissue navigation system in urologic laparoscopic surgery is an evolving technique. Objective: To evaluate a novel soft tissue navigation system developed to enhance the surgeon's perception and to provide decision-making guidance directly before initiation of kidney resection for laparoscopic partial nephrectomy (LPN). Design, setting, and participants: Custom-designed navigation aids, a mobile C-arm capable of cone-beam imaging, and a standard personal computer were used. The feasibility and reproducibility of inside-out tracking principles were evaluated in a porcine model with an artificially created intraparenchymal tumor in vitro. The same algorithm was then incorporated into clinical practice during LPN. Interventions: Evaluation of a fully automated inside-out tracking system was repeated in exactly the same way for 10 different porcine renal units. Additionally, 10 patients underwent retroperitoneal LPNs under manual AR guidance by one surgeon. Measurements: The navigation errors and image-acquisition times were determined in vitro. The mean operative time, time to locate the tumor, and positive surgical margin were assessed in vivo. Results and limitations: The system was able to navigate and superpose the virtually created images and real-time images with an error margin of only 0.5 mm, and fully automated initial image acquisition took 40 ms. The mean operative time was 165 min (range: 135-195 min), and mean time to locate the tumor was 20 min (range: 1327 min). None of the cases required conversion to open surgery. Definitive histology revealed tumor-free margins in all 10 cases. Conclusions: This novel AR tracking system proved to be functional with a reasonable margin of error and image-to-image registration time. Mounting the pre- or intraoperative imaging properties on real-time videoendoscopic images in a real-time manner will simplify and increase the precision of laparoscopic procedures. (C) 2009 European Association of Urology Published by Elsevier B.V. All rights reserved.
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    Is Type 2 Diabetes Mellitus a Predictive Factor for Incontinence After Laparoscopic Radical Prostatectomy? A Matched Pair and Multivariate Analysis
    (Elsevier Science Inc, 2010) Teber, Dogu; Sofikerim, Mustafa; Ates, Mutlu; Goezen, Ali Serdar; Guven, Oguz; Sanli, Oener; Rassweiler, Jens
    Purpose: We evaluated the effect of diabetes mellitus on incontinence after laparoscopic radical prostatectomy. Materials and Methods: From a series of 2,071 patients 135 with type 2 diabetes mellitus undergoing laparoscopic radical prostatectomy without radiotherapy and with a minimum followup of 24 months were identified. These patients were randomly matched with 135 nondiabetic controls for age, body mass index, preoperative prostate specific antigen, clinical stage, neoadjuvant hormonal therapy, prostate volume, previous surgery, surgeon skills, surgical approach, presence of bladder neck sparing, lymphadenectomy, technique of urethrovesical anastomosis and attempted nerve sparing surgery. Results: Using multivariate analysis age, diabetes mellitus and duration of diabetes mellitus were independent factors for post-prostatectomy incontinence in the whole group. Early continence (0 to 3 months) was observed in 43.7% of patients with diabetes and in 57.8% of nondiabetic controls which was statistically significant (p = 0.02). The rates of continence in patients with diabetes mellitus for 5 or more years at 3, 12 and 24-month evaluations were less than those in patients with diabetes mellitus for less than 5 years, and the difference was statistically significant (36% vs 50%, p = 0.001; 63.9% vs 82.4%, p = 0.02; 91.8% vs 98.6%, p = 0.03, respectively). Conclusions: Patients with type 2 diabetes mellitus need longer to recover continence than nondiabetics after laparoscopic radical prostatectomy. However, type II diabetes mellitus did not affect overall return to continence. Patients with diabetes mellitus for 5 or more years have an almost 5 times increased risk of post-prostatectomy incontinence compared to those with diabetes mellitus for less than 5 years. Diabetic patients should be counseled for the potential negative impact of diabetes mellitus on the recovery of continence after laparoscopic radical prostatectomy.