***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: CONTEXT Laparoscopic-assisted colectomy ( LAC ) has emerged as the preferred minimally invasive surgical strategy for diseases of the colon . The safety and efficacy of LAC for colon cancer are unknown , and the nature and magnitude of any quality -of-life ( QOL ) benefit result ing from LAC for colon cancer is also unknown . OBJECTIVE To compare short-term QOL outcomes after LAC vs open colectomy for colon cancer . DESIGN , SETTING , AND PARTICIPANTS Multicenter , r and omized controlled trial ( Clinical Outcomes of Surgical Therapy [ COST ] ) . Between September 1994 and February 1999 , 37 of 48 centers provided data for the QOL component of the trial for 449 consecutive patients with clinical ly resectable colon cancer . MAIN OUTCOME MEASURES Scores on the Symptoms Distress Scale ( SDS ) , Quality of Life Index , and a single-item global rating scale at 2 days , 2 weeks , and 2 months postoperative ; duration of postoperative in-hospital analgesic use ; and length of stay . RESULTS Of 449 patients , 428 provided QOL data . In an intention-to-treat analysis comparing SDS pain intensity , SDS summary , QOL Index summary , and global rating scale scores at each time point , the only statistically significant difference observed between groups was the global rating scale score for 2 weeks postsurgery . The mean ( median ) global rating scale scores for 2 weeks postsurgery were 76.9 ( 80 ) for LAC vs 74.4 ( 75 ) for open colectomy ( P = .009 ) . While in the hospital , patients assigned to LAC required fewer days of both parenteral analgesics compared with patients assigned to open colectomy ( mean [ median ] , 3.2 [ 3 ] vs 4.0 [ 4 ] days ; P<.001 ) and oral analgesics ( mean [ median ] , 1.9 [ 1 ] vs 2.2 [ 2 ] days ; P = .03 ) . CONCLUSION Only minimal short-term QOL benefits were found with LAC for colon cancer compared with st and ard open colectomy . Until ongoing trials establish that LAC is as effective as open colectomy in preventing recurrence and death from colon cancer , this procedure should not be offered to patients with colon cancer The development of operative laparoscopic surgery is linked to advances in ancillary surgical instrumentation . Ultrasonic energy devices avoid the use of electricity and provide effective control of small to medium-sized vessels . Bipolar computercontrolled electrosurgical technology eliminates the disadvantages of electrical energy , and a mechanical blade adds a cutting action . This instrument can provide effective hemostasis of large vessels up to 7 mm . Such devices significantly increase the cost of laparoscopic procedures , however , and the amount of evidence -based information on this topic is surprisingly scarce . This study compared the effectiveness of three different energy sources on the laparoscopic performance of a left colectomy . The trial included 38 nonselected patients with a disease of the colon requiring an elective segmental left-sided colon resection . Patients were preoperatively r and omized into three groups . Group I had electrosurgery ; vascular dissection was performed entirely with an electrosurgery generator , and vessels were controlled with clips . Group II underwent computer-controlled bipolar electrosurgery ; vascular and mesocolon section was completed by using the 10-mm Ligasure device alone . In group III , 5-mm ultrasonic shears ( Harmonic Scalpel ) were used for bowel dissection , vascular pedicle dissection , and mesocolon transection . The mesenteric vessel pedicle was controlled with an endostapler . Demographics ( age , sex , body mass index , comorbidity , previous surgery and diagnoses requiring surgery ) were recorded , as were surgical details ( operative time , conversion , blood loss ) , additional disposable instruments ( number of trocars , EndoGIA charges , and clip appliers ) , and clinical outcome . Intraoperative economic costs were also evaluated . End points of the trial were operative time and intraoperative blood loss , and an intention-to-treat principle was followed . The three groups were well matched for demographic and pathologic features . Surgical time was significantly longer in patients operated on with conventional electrosurgery vs the Harmonic Scalpel or computed-based bipolar energy devices . This finding correlated with a significant reduction in intraoperative blood loss . Conversion to other endoscopic techniques was more frequent in Group I ; however , conversion to open surgery was similar in all three groups . No intraoperative accident related to the use of the specific device was observed in any group . Immediate outcome was similar in the three groups , without differences in morbidity , mortality , or hospital stay . Analysis of operative costs showed no significant differences between the three groups . High-energy power sources specifically adapted for endoscopic surgery reduce operative time and blood loss and may be considered cost-effective when left colectomy is used as a model Reports of trocar and extraction site tumor recurrences following  laparoscopic colectomy  raise concern that such recurrences may be occurring more frequently with laparoscopic compared with open colectomy . Contemporary data on the incidence of incisional recurrence following open colectomy , in the age of adjuvant therapies , are not available . PURPOSE : This study was undertaken to examine the incidence and clinical features of wound recurrence in current prospect i ve trials including 1,711 patients with primary adenocarcinoma of the colon or rectum treated for cure . METHODS : Files of all patients with recurrence ( n=623 ) were review ed . Each site of recurrence was recorded separately . All patients have been followed prospect ively , and 3-year and 4-year data are mature on 100 and 70 percent , respectively . Stage at diagnosis was B2 in 344 patients and C in 1,367 patients ( > 4 nodes positive in 346 patients ) . RESULTS : Recurrence was identified in 623 patients ( 36.4 percent ) and occurred at a mean of 1.5 years following primary treatment . Eleven patients ( 0.6 percent ) had documented incisional recurrences ( 9 abdominal wound , 1 perineal wound , and 1 stoma wound ) . Only four were diagnosed clinical ly , and the remaining seven were diagnosed incidentally at reoperation . Of 11 patients with  incisional wound recurrences , 2 had primary Stage B2 and 9 had primary Stage C disease . Nine of 11 patients were found to have multiple sites of recurrence at time of recurrence . At a mean follow-up of 1.8 years after recurrence , 3 of 11 patients are alive with disease , although 8 have died because of disease . CONCLUSIONS : Incisional recurrence is uncommon , although likely underestimated , following conventional treatment of colorectal carcinoma . Its occurrence is usually a harbinger of diffuse intra-abdominal disease . These data may provide useful information for investigations of laparoscopic approaches to colon cancer BACKGROUND The safety and benefits of laparoscopic colon resection are well documented . However , few reports have addressed the safety and comparative outcome of laparoscopic colon operations that necessitated conversion . METHODS All consecutive laparoscopic colon resections performed by a single surgeon from July 1996 to October 2003 were assessed . Data obtained from a prospect i ve computerized data base included demographics , diagnosis , reason and time to conversion , length of stay , morbidity , and mortality . Additionally , all  laparoscopic-converted colectomies  were then matched with open colectomies by diagnosis and severity of disease and analyzed with respect to morbidity , mortality , and clinical outcome . RESULTS A total of 143 laparoscopic colon resections were analyzed , 78 of which were  left colon resections and 65 were right colon resections .  The overall conversion rate was 19.6 % ( 28 patients ) . The disease entities of the 28 converted patients were diverticulitis ( 16 ) , polyps ( four ) , Crohn 's disease ( three ) , metastatic cancer ( three ) , and others ( two ) . Conversion was higher in the left-sided ( 24 patients , 30.8 % ) versus right-sided ( four patients , 6.1 % ) procedures . There were no differences regarding age , gender , and comorbidities among the laparoscopic , open , and converted groups ; the median follow-up was 39 months . The median length of stay was 6 , 8 , and 12 days for the laparoscopic , open , and converted groups , respectively . Right-sided conversions were due to the size of the inflammatory mass in three patients and intraoperative bleeding in one patient . Left-sided conversions were due to the inflammatory process extending beyond the sigmoid colon in 12 patients , adhesions in five , obesity in four , pericolonic abscess in two , and fixed mass in one patient . Postoperative morbidity was significantly higher for laparoscopic procedures that were converted to open procedures more than 30 min into the operation . Preoperative predictors of conversion were extent of inflammatory process beyond the sigmoid colon and obesity , whereas intraoperative predictors were adhesions and bleeding . CONCLUSIONS Laparoscopic-converted colon resection is associated with significantly greater morbidity , particularly wound complications and greater length of hospital stay , compared to open or laparoscopic colectomies . Prompt conversion ( < 30 min ) may reduce the overall morbidity associated with converted procedures . Furthermore , thoughtful patient selection may decrease the conversion rate and thereby prevent the inherent morbidity associated with converted procedures Background : A shorter duration of postoperative ileus and earlier oral alimentation of patients may be a clinical ly relevant benefit of laparoscopic compared with conventional colorectal resection . Patients / Methods : A total of 60 patients were r and omised to either laparoscopic ( n=30 ) or conventional ( n=30 ) resection of colorectal tumours . Major endpoints were the postoperative time to the first bowel movement and the time until oral feeding without parenteral alimentation was tolerated . Minor endpoints were the postoperative interval to the first peristalsis and first passage of flatus , the distribution of radio-opaque markers in abdominal radiographs on day 3 and day 5 and the incidence of postoperative vomiting . Results : Age , gender , ASA-classification and type of resection were comparable in thetwo groups . Peristalsis was first noticed 26±9 h after laparoscopic and 38±17 h after conventional colorectal resection ( P<0.01 ) . First flatus occurred 50±19 h after laparoscopic and 79±21 h after conventional surgery ( P<0.01 ) . The incidence of postoperative vomiting was similar in both groups . Three days after surgery radio-opaque markers were found more often in the right colon ( P<0.01 ) and less often in the small intestine ( P<0.05 ) in laparoscopic compared with conventional patients . Five days after laparoscopic surgery , more markers had reached the left colon ( P<0.05 ) . The first bowel movement occurred 70±32 h after laparoscopic and 91±22 h after conventional resection ( P<0.01 ) . Oral feeding without additional parenteral alimentation was tolerated 3.3±0.7 days after laparoscopic and 5.0±1.5 days after conventional surgery ( P<0.01 ) . Conclusion : The shorter duration of postoperative ileus allows earlier restoration of oral feeding after laparoscopic compared with conventional colorectal resection and therefore increases quality of life immediately after resection of colorectal tumours PURPOSE : The aim of this study was to review our experience with laparoscopic colorectal cancer surgery for palliative purpose s and to assess its safety and efficacy . METHODS : This was a prospect i ve analysis of 30 patients with incurable colorectal cancer considered for laparoscopic surgery for palliative purpose s. RESULTS : Resection of a single segment of the bowel was performed in 15 patients ( 6 right and 1 left colectomies and 8 proctosigmoidectomies ) . One patient underwent both right colectomy and sigmoidectomy  because of double lesions . Stoma creation only was performed in 11 patients ( 5 colostomies and 6 ileostomies ) . Three patients were converted to an open procedure . For resection , median operative time was 170 minutes , and median estimated blood loss was 150 ml . For stoma creation , median operative time was 60 minutes , and median blood loss was 50 ml . There were no intraoperative complications . Postoperative death occurred in two severely debilitated patients after stoma creation . One patient developed a pulmonary embolism eight days postoperatively , later dying of pulmonary failure . Another patient died six hours after loop colostomy . Autopsy was refused . There were no other postoperative complications . Median time to passage of flatus was two days and of stool five days after resection and two days for both flatus and stool after stoma creation . Median time to discharge was eight days after resection and seven days after stoma creation . All patients were able to eat and recover normal bowel function . Among the resection group , six patients died ( median time to death , 12 months ) during a median follow-up period of 13 months . Among the stoma creation group , five patients died ( median time to death , 8 months ) during median follow-up period of ten months . There were no port-site recurrences . CONCLUSION : The laparoscopic approach for patients with incurable colorectal cancer can provide effective palliation with avoidance of a major laparotomy in the majority of cases BACKGROUND Minimally invasive , laparoscopically assisted surgery was first considered in 1990 for patients undergoing colectomy for cancer . Concern that this approach would compromise survival by failing to achieve a proper oncologic resection or adequate staging or by alter 
    Output:
    
The principal conclusions are that the laparoscopic approach affords better short-term outcomes including surgical site morbidity , but with increased operative times and direct costs .
Among the proven long-term outcomes , cancer recurrence and survival do not seem to be worse .
Whether conversion , a source of increased operative time and costs , is responsible for poorer outcomes or whether specific setting s associated with poorer outcomes are among the causes of conversion remains to be shown .
However , there are still concerns as regards specific laparoscopic-related complications .
Conclusion : There seems to no real safety problems in performing laparoscopic colectomy  for cancer ; improvement in operative times , conversion rates , and complications should make laparoscopy the best cost-effective approach to colectomy