***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background The purpose of this study is to compare and evaluate the security and efficacy of 3D vs 2D laparoscopy in rectal cancer treatment . Methods Forty-six patients who suffered from rectal cancer and went on laparoscopic radical resection of rectal carcinoma in Peking University Shougang Hospital from Feb. 2015 to Mar. 2016 were included in the study . They were r and omly divided into two groups . The 23 patients operated with the 3D system were compared with 23 patients operated with the 2D system by perioperative data . Results There were no significant differences in age , sex , pathological type , tumor differentiation , TNM staging , and surgical procedures ( P > 0.05 ) . The average operating time of 3D laparoscopic surgery group ( 172.2 ± 27.5 min ) was shorter than that of 2D group ( 192.6 ± 22.3 ) ( P < 0.05 ) ; the rate of transfer to laparotomy is lower in 2D group ( 72.7 % ) than in 3D group ( 86.4 % ) , but they have no significant difference ; and the intraoperative blood loss ( 247.0 ± 173.6 ml vs 282.6 ± 195.6 ml ) , postoperative passage of flatus ( 2.8 ± 0.8 days vs 3.1 ± 1.0 days ) , and indwelling catheter time ( 5.6 ± 1.9 days vs 6.3 ± 2.0 days ) in 3D group and 2D group ( P > 0.05 ) were not significantly different . There were no differences in other complications between the two groups . No significantly different recrudescence and death rates were found between the two groups ( P > 0.05 ) . Conclusion The 3D laparoscopy shortens the operation time of rectum cancer . 3D laparoscopic surgery is more efficient in treatment of rectal cancer than 2D laparoscopy and is worth of being generalized Importance Robotic rectal cancer surgery is gaining popularity , but limited data are available regarding safety and efficacy . Objective To compare robotic-assisted vs conventional laparoscopic surgery for risk of conversion to open laparotomy among patients undergoing resection for rectal cancer . Design , Setting , and Participants R and omized clinical trial comparing robotic-assisted vs conventional laparoscopic surgery  among 471 patients with rectal adenocarcinoma suitable for curative resection conducted at 29 sites across 10 countries , including 40 surgeons . Recruitment of patients was from January 7 , 2011 , to September 30 , 2014 , follow-up was conducted at 30 days and 6 months , and final follow-up was on June 16 , 2015 . Interventions Patients were r and omized to robotic-assisted ( n = 237 ) or conventional ( n = 234 ) laparoscopic rectal cancer resection  , performed by either high ( upper rectum ) or low ( total rectum ) anterior resection or abdominoperineal resection ( rectum and perineum ) . Main Outcomes and Measures The primary outcome was conversion to open laparotomy . Secondary end points included intraoperative and postoperative complications , circumferential resection margin positivity ( CRM+ ) and other pathological outcomes , quality of life ( 36-Item Short Form Survey and 20-item Multidimensional Fatigue Inventory ) , bladder and sexual dysfunction ( International Prostate Symptom Score , International Index of Erectile Function , and Female Sexual Function Index ) , and oncological outcomes . Results Among 471 r and omized patients ( mean [ SD ] age , 64.9 [ 11.0 ] years ; 320 [ 67.9 % ] men ) , 466 ( 98.9 % ) completed the study . The overall rate of conversion to open laparotomy was 10.1 % : 19 of 236 patients ( 8.1 % ) in the robotic-assisted laparoscopic group and 28 of 230 patients ( 12.2 % ) in the conventional laparoscopic group ( unadjusted risk difference = 4.1 % [ 95 % CI , −1.4 % to 9.6 % ] ; adjusted odds ratio = 0.61 [ 95 % CI , 0.31 to 1.21 ] ; P = .16 ) . The overall CRM+ rate was 5.7 % ; CRM+ occurred in 14 ( 6.3 % ) of 224 patients in the conventional laparoscopic group and 12 ( 5.1 % ) of 235 patients in the robotic-assisted laparoscopic group ( unadjusted risk difference = 1.1 % [ 95 % CI , −3.1 % to 5.4 % ] ; adjusted odds ratio = 0.78 [ 95 % CI , 0.35 to 1.76 ] ; P = .56 ) . Of the other 8 reported prespecified secondary end points , including intraoperative complications , postoperative complications , plane of surgery , 30-day mortality , bladder dysfunction , and sexual dysfunction , none showed a statistically significant difference between groups . Conclusions and Relevance Among patients with rectal adenocarcinoma suitable for curative resection , robotic-assisted laparoscopic surgery , as compared with conventional laparoscopic surgery , did not significantly reduce the risk of conversion to open laparotomy . These findings suggest that robotic-assisted laparoscopic surgery , when performed by surgeons with varying experience with robotic surgery , does not confer an advantage in rectal cancer resection . Trial Registration is rct n.org Identifier : IS RCT Aim The aim of this study is to compare pathological findings in rectal cancer specimens obtained by  laparoscopy or laparotomy . Material s and Methods Bowel length , distal and circumferential margins , and number of total and positive nodes harvested were prospect ively recorded in specimens obtained from 100 consecutive patients who had a laparoscopic total mesorectal excision for cancer . These data were compared with those extracted from a well-matched group of 100 patients who had an open procedure . Results The mean length of the specimens was 31.04 cm in the case group and 29.45 cm in the control group ( not significant ( NS ) ) . All distal margins in both groups were negative . The circumferential margin was positive in four cases in the case group and nine cases in the control group ( NS ) . The mean number of lymph nodes harvested was 13.76 nodes/patient in the case group and 12.74 nodes/patient in the control group ( NS ) . The mean number of involved lymph nodes was 1.18 node/case in the case group and 1.96 node/case in group 2 ( NS ) . Conclusion There is no difference between laparoscopic or open approaches concerning specimen 's length , distal margin , circumferential margin , and total and positive lymph nodes .  Laparoscopic rectal resection is not only technically feasible but it seems also oncologically safe OBJECTIVE To determine whether the use of 3-dimensional ( 3D ) imaging translates into a better surgical performance of naïve urologic laparoscopic surgeons during pyeloplasty ( PY ) and partial nephrectomy ( PN ) procedures . MATERIAL S AND METHODS Eighteen surgeons without any previous laparoscopic experience were r and omly assigned to perform PY and PN in a porcine model using initially 2-dimensional ( 2D ) and 3D laparoscopy . A surgical performance score was rated by an " expert " tutor through a modified 5-item global rating scale contemplating operative field view , bimanual dexterity , efficiency , tissue h and ling , and autonomy . Overall surgical time , complications , subjective perception of participating surgeons , and inconveniences related to the 3D vision were recorded . RESULTS No difference in terms if operative time was found between 2D or 3D laparoscopy for both the PY ( P = .51 ) and the PN ( P = .28 ) procedures . A better rate in terms of surgical performance score was noted by the tutors when the study participants were using 3D vs 2D , for both PY ( 3.6 [ 0.8 ] vs 3.0 [ 0.4 ] ; P = .034 ) and PN ( 3.6 [ 0.51 ] vs 3.15 [ 0.63 ] ; P = .001 ) . No complications occurred in any of the procedures . Most ( 77.2 % ) of the participating naïve laparoscopic surgeons had the perception that 3D laparoscopy was overall easier than 2D . Headache ( 18.1 % ) , nausea ( 18.1 % ) , and visual disturbance ( 18.1 % ) were the most common issues reported by the surgeons during 3D procedures . CONCLUSION Despite the absence of translation in a shorter operative time , the use of 3D technology seems to facilitate the surgical performance of naïve surgeons during laparoscopic kidney procedures on a porcine model Background By traditional open surgery , the tumor recurrence rate of total mesorectal excision with sphincter-preserving procedure was lower than that of abdominoperineal resection ( APR ) for the treatment of low rectal cancer . The present study aim ed to rescrutinize whether the same conclusion can be drawn when both surgical procedures are performed laparoscopically . Methods We retrospectively review ed the prospect ively recorded clinicopathologic data of 344 consecutive patients with low rectal cancer , in which 170 patients underwent preoperative chemoradiotherapy followed by laparoscopic total mesorectal excision ( TME ) , whereas 174 patients underwent laparoscopic TME directly without chemoradiotherapy .  Such patients were further stratified according to the pathologic tumor , node , metastasis stage ( stage II or III disease ) and surgical strategy ( APR or sphincter-preserving operation [ SPO ] ) . The surgical procedures are presented in supplemental videos . The disease-free survival , recurrence patterns , and functional recovery of patient groups stratified as appropriate were compared . Results In patients who received preoperative chemoradiotherapy , the estimated recurrence rate were similar between laparoscopic TME with SPO and laparoscopic APR with 10.6 % , 7 of 66 , versus 18.5 % , 5 of 27 , in stage II disease ( p = 0.811 , log-rank test ) ; and 19.3 % , 11 of 57 , versus 20 % , 4 of 20 , in stage III disease ( p = 0.980 ) . In patients without preoperative chemoradiotherapy , the recurrence rate was significantly higher in laparoscopic APR than in the laparoscopic TME with SPO group of patients with stage III disease ( 45 % , 9 of 20 , vs. 19.3 % , 16 of 83 , p = 0.025 ) , whereas the recurrence rate of the two procedures was similar ( 21.4 % , 3 of 14 , vs. 17.5 % , 10 of 57 , p = 0.702 ) in stage II disease . Conclusions When low rectal cancer was operated on by laparoscopic approach , the poorer prognosis of APR compared to SPO was only observed in stage III patients without preoperative chemoradiotherapy Background Common video systems for laparoscopy provide the surgeon a two-dimensional image ( 2D ) , where information on spatial depth can be derived only from secondary spatial depth cues and experience . Although the advantage of stereoscopy for surgical task efficiency has been clearly shown , several attempts to introduce three-dimensional ( 3D ) video systems into clinical routine have failed . The aim of this study is to evaluate users ’ performances in st and ardised surgical phantom model tasks using 3D HD visualisation compared with 2D HD regarding precision and working speed . Methods This comparative study uses a 3D HD video system consisting of a dual-channel laparoscope , a stereoscopic camera , a camera controller with two separate outputs and a wavelength multiplex stereoscopic monitor .  Each of 20 medical students and 10 laparoscopically experienced surgeons ( more than 100 laparoscopic cholecystectomies each ) pre-selected in a stereo vision test were asked to perform one task to familiarise themselves with the system and subsequently a set of five st and ardised tasks encountered in typical surgical procedures . The tasks were performed under either 3D or 2D conditions at r and om choice and subsequently repeated under the other vision condition . Predefined errors were counted , and time needed was measured . Results In four of the five tasks the study participants made fewer mistakes in 3D than in 2D vision . In four of the tasks they needed significantly more time in the 2D mode . Both the student group and the surgeon group showed similarly improved performance , while the surgeon group additionally saved more time on difficult tasks . Conclusions This study shows that 3D HD using a state-of-the-art 3D monitor permits superior task efficiency , even as compared with the latest 2D HD video systems Background To address the issue whether three-dimensional ( 3D ) offers real operative time advantages to the laparoscopic surgical procedure , we have design ed a single-surgeon prospect i ve r and omized comparison of 3D versus two-dimensional ( 2D ) imaging during two different bariatric procedures . Methods Forty morbidly obese patients were r and omized on the day of surgery by a r and om computer-generated allocation list to receive either a 3D high-definition ( HD ) display or 2D HD imaging system laparoscopic bariatric procedure by a single experienced surgeon . Forty operations were performed with either a 3D HD 
    Output:
    
In summary , 3D laparoscopic rectal surgery appears to have advantages over 2D laparoscopic rectal surgery in terms of positive CRM and operation time ; however , it is not better than 2D laparoscopic rectal surgery in terms of the conversion rate and postoperative complications