Evaluation of three laparoscopic modalities: robotics versus three-dimensional vision laparoscopy versus standard laparoscopy.

PURPOSE: Standard laparoscopy has undergone many recent advances with the advent of three-dimensional visual systems and robotic surgical systems. In evaluating the usefulness of these new systems, it is difficult to objectively measure their advantages in the operating room. Therefore, we designed a trial using three different laparoscopic modalities to evaluate the strengths and weaknesses of each modality. MATERIALS AND METHODS: Twenty-seven subjects were entered into the study. Three different laparoscopic modalities were tested. These included standard laparoscopy with two-dimensional cameras, the 3Di Endosite visual system, and the daVinci Robotic Surgical System. A standard laparoscopic trainer was utilized and testing consisted of three different tasks: peg transfer, ring manipulation, and cannulation. RESULTS: Of the 27 subjects, 16 (60%) reported some degree of laparoscopic experience. The number of pegs transferred with standard laparoscopy and the Endosite 3Di system was significantly greater than with the robot. The number of errors committed during the peg transfer test and the amount of time required was significantly lower with the Endosite 3Di system compared to the robot. Subjects completed the ring manipulation task significantly faster with the robot, but the number of errors committed was no different among the three modalities. Subjects were able to complete the cannulation task with their dominant hand significantly faster with the robot compared to the Endosite 3Di system or standard laparoscopy, and committed fewer errors using the robot compared to standard laparoscopy. CONCLUSIONS: This study showed improved performance using three-dimensional optics on some tasks, but not a significant improvement in overall results. Three-dimensional vision does appear beneficial during performance of some complex tasks. The wrist-like action of the robot improved performance on some tasks, while the lack of tactile feedback likely was a source of errors on other tasks.

Interstitial laser ablation of the kidney: acute and chronic porcine study using new-generation diffuser tip fiber.

BACKGROUND AND PURPOSE: Many ablative techniques have been described for treatment of small renal tumors. We investigated interstitial laser ablation (ILA) of porcine kidneys with a new-generation diffuser tip fiber. MATERIALS AND METHODS: Six female farm pigs underwent bilateral lower-pole ILA of normal kidneys via a midline approach. The acute group consisted of three pigs that underwent immediate post-treatment bilateral nephrectomy, while the chronic group survived for 45 days prior to bilateral nephrectomy. The lower pole of each kidney was treated with a diode laser in temperature-adaptive mode (100 degrees C) with the diffuser tip fiber. The treatment time was increased for each pig in each group, from 4 minutes to 8 minutes to 12 minutes. RESULTS: The acute lesions were elliptical, with the depth being longer than the width. The dimensions of the acute lesions on gross inspection were 18 x 9 and 17 x 9 mm in the 4-minute treatment pig, 25 x 6 and 18 x 15 mm in the 8-minute treatment pig, and 22 x 18 and 19 x 12-mm in the 12-minute treatment pig. Reduced nicotinamide adenine dinucleotide staining of the acute lesions revealed a nonviable zone of 14 x 18 and 15 x 10 mm in the 4-minute treatment pig, 16 x 8 and 12 x 7 mm in the 8-minute treatment pig, and 11 x 7 and 14 x 9 mm in the 12-minute treatment pig. Histologic architecture was preserved. Gross examination of the chronic kidney revealed a divot with a scar in the treatment area. Histologic examination showed an irregularly shaped area of fibrosis and loss of normal architecture, with the lesions being smaller than those seen on the acute sections. CONCLUSIONS: Interstitial laser ablation of the kidney with a diffuser tip fiber produces adequate cell death but small lesions. Further studies with multiple fibers or active monitoring and repositioning of the fiber to produce larger lesions are necessary.

Digital rectal examination is barrier to population-based prostate cancer screening.

OBJECTIVES: To determine whether use of the digital rectal examination (DRE) results in decreased participation in prostate cancer (PCa) screening, which, in turn, would result in lower detection. Population-based PCa screening includes prostate-specific antigen (PSA) measurement with or without a DRE. PSA and DRE screening provide greater sensitivity than PSA alone; however, the increased participation rate resulting from PSA-alone screening may result in a greater detection rate. METHODS: We performed a survey of 13,580 healthy men undergoing PSA-only population-based screening. In addition to the basic demographic information, the survey asked whether the participant would still be willing to participate in the screening if it included a DRE. We modeled the willingness to participate to assess the effect of PSA screening versus PSA and DRE screening on the basis of previously published data and our results. RESULTS: The results of our study indicated that only 78% of men would participate in screening that included both DRE and PSA. Thus, 7800 men of a theoretical population of 10,000 would participate in a screening that included both DRE and PSA. The positive screen rate (PSA > or = 4.0 ng/mL and/or abnormal DRE) would then have been 2013, with 472 PCa cases and 1540 negative biopsies. In the PSA-alone arm, all 10,000 men would have agreed to participate, and the positive screen rate (PSA > or = 4.0 ng/mL) would have been 1480, with 499 PCa cases and 980 negative biopsies. The PSA-alone arm would thus have detected 27 more cancers and performed 560 fewer negative biopsies. CONCLUSIONS: The results of our study have demonstrated that DRE is a significant barrier to participation in PCa screening. PSA plus DRE-based programs result in fewer cases of PCa detected, with a significant increase in negative biopsies. We, therefore, suggest that future mass screening efforts include only PSA determination and omit the DRE.