***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 : Surgical technique using small-diameter instruments and single-incision laparoscopy are two new options for less invasive laparoscopic cholecystectomy ( LC ) .  In this study , we have compared mini-LC ( MLC ) with single-incision LC ( SILC ) . Material s and Methods : This study is a r and omized clinical trial conducted on the patients diagnosed with symptomatic cholelithiasis who underwent LC . Forty patients were r and omized to two equal groups of MLC and SILC . They were compared in terms of demographic data , operation time , and surgical complications . Results : Baseline characteristics were similar in two groups . Operation time in MLC was significantly shorter than that in SILC ( 45.1 ± 69 min vs 63.75 ± 7.57 min , P-value < 0.001 ) . Also , the total length of the wound in SILC group was shorter than that in MLC group ( P-value < 0.003 ) . Postoperative pain scores were similar in two groups . Hospital stay was shorter in MLC ( 1.2 ± 0.6 days vs 1.6 ± 0.8 days , P < 0.021 ) . There was no difference in postoperative complications in two groups . Conclusion : MLC because of less operation time is preferred than SILC . Also , by subjective measures , it was a more comfortable method compared to SILC Purpose : To evaluate the safety and feasibility of single-incision laparoscopic cholecystectomy ( SILS-C ) compared with conventional laparoscopic cholecystectomy ( CLC ) . Methods : Sixty-five patients ( SILS-C : 35 , CLC : 30 ) were prospect ively enrolled and operated with conventional straight instruments . The postoperative pain scores at 6 , 24 hours , and 1 week , nausea , vomiting , commencement of oral intake , hospital stay , resumption of normal activities and work and satisfaction levels were noted . Results : Twenty-eight percent ( 10/35 ) SILS-C patients required introduction of additional trocars to complete the procedure . No patient required conversion to open . All the morbidity parameters were similar in both the groups , except that the seroma formation in the wound was significantly higher in the SILS-C group [ SILS-C : 17 % (6/35)/CLC : 0 % , P=0.038 ] . One patient in SILS-C had a major bile duct injury . Conclusions : SILS-C is safe and feasible with conventional instruments . However , caution needs to be exercised in view of a major bile duct injury and a higher rate of seroma formation in the wound Nowadays ,  laparoscopic donor nephrectomy ( LDN ) has become the gold st and ard to procure live donor kidneys . As the relationship between donor and recipient loosens , it becomes of even greater importance to optimize safety and comfort of the surgical procedure . Low‐pressure pneumoperitoneum has been shown to reduce pain scores after laparoscopic cholecystectomy . Live kidney donors may also benefit from the use of low pressure during LDN . To evaluate feasibility and efficacy to reduce post‐operative pain , we performed a r and omized blinded study . Twenty donors were r and omly assigned to st and ard ( 14 mmHg ) or low ( 7 mmHg ) pressure during LDN . One conversion from low to st and ard pressure was indicated by protocol due to lack of progression . Intention‐to‐treat analysis showed that low pressure result ed in a significantly longer skin‐to‐skin time ( 149 ± 86 vs. 111 ± 19 min ) , higher urine output during pneumoperitoneum ( 23 ± 35 vs. 11 ± 20 mL/h ) , lower cumulative overall pain score after 72 h ( 9.4 ± 3.2 vs. 13.5 ± 4.5 ) , lower deep intra‐abdominal pain score ( 11 ± 3.3 vs. 7.5 ± 3.1 ) , and a lower cumulative overall referred pain score ( 1.8 ± 1.9 vs. 4.2 ± 3 ) . Donor serum creatinine levels , complications , and quality of life dimensions were not significantly different . Our data show that low‐pressure pneumoperitoneum during LDN is feasible and may contribute to increase  live donors ’ comfort during the early post‐operative phase Background Nonobese patients undergoing laparoscopic procedures present a dilemma as to the correct mode of entry into the abdominal cavity because the Veress needle ( VN ) technique seems to be associated with a high risk of vascular and visceral injuries . Direct trocar insertion ( DTI ) has been reported as an alternative to the VN for creation of the pneumoperitoneum . Methods An open comparative r and omized prospect i ve study was conducted on the feasibility and safety of DTI vs the VN technique in nonobese patients of any age category referred for urgent or scheduled laparoscopic procedures . Exclusion criteria were obesity ( defined as a body mass index [ BMI ] > 27 kg/m2 ) , major abdominal distension , and two or more previous abdominal operations . The study endpoints were the feasibility and safety of the DTI and VN techniques . Results were evaluated on an intention-to-treat basis . Statistical analysis was carried out with the t-test for independent sample s , the chi-square tests , and the Fisher ’s exact tests , as appropriate . The level of significance was 0.01 . Results Since January 2002 , a total of 598 nonobese patients have been entered into the current trial ; 46 % ( mean BMI 21.6 Â± 4.4 kg/m2 ) were r and omly allocated to DTI , whereas 54 % ( BMI 21.1 Â± 5.3 kg/m2 ) were allocated to the VN techniques . Demographic features and type of procedures were similar for the two groups . DTI was feasible in 100 % of patients vs 98.7 % in the VN group ( p = NS ) . Minor complications were nil in the DTI group and 5.9 % in the VN group ( p < 0.01 ) . The latter group consisted of 11 cases ( 3.4 % ) of subcutaneous emphysema and eight cases ( 2.5 % ) of extraperitoneal insufflation . Major complications were nil in the DTI group and 1.3 % among VN patients ( p = NS ) . These latter cases consisted of two ( 0.3 % ) hepatic lesions managed laparoscopically ; one ( 0.3 % ) misdiagnosed ileal perforation requiring reintervention , and one ( 0.3 % ) mesenteric laceration treated conservatively . Conclusion In thin and very thin patients of any age category with no more than one previous abdominal operation , DTI is a safe alternative to the VN technique and is associated with fewer minor complications . In terms of major complications , there is no difference between the two techniques . Either technique of access is acceptable Thin and very thin patients undergoing laparoscopy , on condition that the basic principles of laparoscopic surgery are complied with Purpose Laparoscopic techniques have allowed surgeons to perform complicated intra-abdominal surgery with minimal trauma . Single incision laparoscopic surgery ( SILS ) was developed with the aim of reducing the invasiveness of conventional laparoscopy . In this study we aim ed to compare results of SILS cholecystectomy and three port conventional laparoscopic ( TPCL ) cholecystectomy prospect ively . Methods In this prospect i ve study , 100 patients who underwent laparoscopic cholecystectomy for gallbladder disease were r and omly allocated to  SILS cholecystectomy ( group 1 ) or  TPCL cholecystectomy  ( group 2 ) . Demographics , pathologic diagnosis , operating time , blood loss , length of hospital stay , complications , pain score , conversion rate , and satisfaction of cosmetic outcome were recorded . Results Forty-four SILS cholesystectomies ( 88 % ) and 42 TPCL cholecystectomies ( 84 % ) were completed successfully . Conversion to open surgery was required for 4 cases in group 1 and 6 cases in group 2 . Operating time was significantly longer in group 1 compared with group 2 ( 73 minutes vs. 48 minutes ; P < 0.05 ) . Higher pain scores were observed in group 1 versus group 2 in postoperative day 1 ( P < 0.05 ) . There was higher cosmetic satisfaction in group 1 ( P < 0.05 ) . Conclusion SILS cholecystectomy performed by experienced surgeons is at least as successful , feasible , effective and safe as a TPCL cholecystectomy . Surgeons performing SILS should have a firm foundation of advanced minimal access surgical skills and a cautious , gra date d approach to attempt the various procedures . Prospect i ve r and omized studies comparing single access versus conventional multiport laparoscopic cholecystectomy , with large volumes and long-term follow-up , are needed to confirm our initial experience . ( Clinical Trials.gov Identifier : NCT01772745 . OBJECTIVE In trocar-cannula systems , increased entry force could result in loss of operator control , a potential cause of serious visceral and vascular injuries . We developed a system to measure entry force and intraperitoneal pressure to evaluate and compare trocar-cannula systems . METHODS Six laparoscopic trocar-cannula systems of similar diameter ( 12 mm ) were tested ( two pyramidal , two cutting-dilating , and two blunt conical ) using a white swine model . All six systems were inserted into each of 12 subjects with location design ated by r and om allotment ( 72 insertions ) . During each insertion , intraperitoneal pressure and entry force were measured using a system consisting of a gas-gas transducer , a 50-lb load cell , and a multichannel data acquisition board . Mean entry force and intraperitoneal pressure were compared using mixed-model analysis of variance . RESULTS Mean entry force measurements were as follows : pyramidal 9.01 lb and 13.48 lb , cutting-dilating 9.94 lb and 16.46 lb , and blunt conical 19.15 lb and 31.91 lb . Intraperitoneal pressure changes generally reflected measured entry force . CONCLUSION The system successfully measured both entry force and result ant intraperitoneal pressure .  Pyramidal trocar-cannula systems required the lowest force for entry . These differences in entry force have potential clinical implication s related to the risk of visceral and vascular injury . Intraperitoneal pressure measurement could be used as a surrogate for insertional force measurement Background Post-laparoscopic pain syndrome is well recognized and characterized by abdominal and particularly shoulder tip pain ; it occurs frequently following laparoscopic cholecystectomy . The etiology of post-laparoscopic pain can be classified into three aspects : visceral , incision , and shoulder . The origin of shoulder pain is only partly understood , but it is commonly assumed that the cause is overstretching of the diaphragmatic muscle fibers owing to a high rate of insufflations . This study aim ed to compare the frequency and intensity of shoulder tip pain between  low-pressure ( 7 mmHg ) and st and ard-pressure  ( 14 mmHg ) in a prospect i ve r and omized clinical trial . Methods One hundred and forty consecutive patients undergoing elective laparoscopic cholecystectomy  were r and omized prospect ively to either high- or low-pressure pneumoperitoneum and blinded by research nurses who assessed the patients during the postoperative period . The statistical analysis included sex , mean age , weight , American Society of Anesthesiologists ( ASA ) grade , operative time , complication rate , duration of surgery , conversion rate , postoperative pain by using visual analogue scale , number of analgesic injections , incidence and severity of shoulder tip pain , and postoperative hospital stay . p < 0.05 was considered indicative of significance . Results The characteristics of the patients were similar in the two groups except for the predominance of males in the st and ard-pressure group ( controls ) . The procedure was successful in 68 of 70 patients in the low-pressure group compared with in 70 patients in the st and ard group . Operative time , number of analgesic injections , visual analogue score , and length of postoperative days were similar in both groups . Incidence of shoulder tip pain was higher in the st and ard-pressure group , but not statistically significantly so ( 27.9 % versus 44.3 % ) ( p = 0.100 ) . Conclusions Low-pressure pneumoperitoneum tended to be better than st and ard-pressure pneumoperitoneum in terms of lower incidence of shoulder tip pain , but this difference did not reach statistical significance following elective laparoscopic cholecystectomy Background and Objectives : Traditional trocar tip design for laparoscopic access incorporates cutting blades to penetrate the body wall . More recently , trocars applying tissue dilation have been used that create a smaller defect , seldom requiring fascial wound closure . Four 12-mm commercially available single-use trocar design s were evaluated for postoperative pain . Methods : The 4-trocar types included 2 cutting ( single or pyramidal bladed ) and 2 dilating trocars ( radially or axially dilating ) type . Fifty-six patients undergoing transperitoneal laparoscopic renal surgery were r and omized and blinded to one of the 4 trocar types . In each case , trocars were placed in a st and ard “ diamond ” configuration : three 12-mm study trocars and a lateral 5-mm trocar that served as a reference point for normalizing patients ' pain scores . Postoperative pain based on a visual analog scale and complications were assessed . 
    Output:
    
Overall there was no evidence of advantage using any single technique for preventing major vascular or visceral complications .
There was no evidence of a difference between the groups in rates of visceral injury or extraperitoneal insufflation .
These patients may have unusually high complication rates .
An open-entry technique is associated with a reduction in failed entry when compared to a closed-entry technique , with no evidence of a difference in the incidence of visceral or vascular injury .
An advantage of direct trocar entry over Veress needle entry was noted for failed entry and vascular injury .