***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*** 
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    Input: HYPOTHESIS Laparoscopy has become a popular approach for the surgical treatment of benign and even malignant colorectal diseases . Several authors have reported better preserved immunity in patients undergoing laparoscopic compared with conventional colorectal surgery .  The present study addresses the hypothesis that specific and nonspecific immunity are differently affected by laparoscopic and conventional colorectal surgery . DESIGN Nonr and omized control trial . SETTING University hospital . PATIENTS Seventy prospect ively enrolled patients with colorectal diseases undergoing laparoscopic ( n = 35 ) or open ( n = 35 ) surgery .  MAIN OUTCOME MEASURES  Blood sample s were taken prior to surgery as well as on days 1 , 3 , and 5 after surgery . Cell numbers of lymphocyte sub population s as well as natural killer cells were determined by flow cytometry , and interleukin 6 and C-reactive protein serum levels were measured . RESULTS Significant differences between study and control patients ( P<.05 ) were detected regarding circulating interleukin 6 and C-reactive protein levels with a reduced proinflammatory response to surgery in patients after  laparoscopic surgery .  Furthermore , postoperative natural killer cell counts were significantly higher in patients after  laparoscopic surgery . The levels of B lymphocytes and T lymphocytes and helper T-cell counts and cytotoxic ( suppressor ) T-cell counts did not show significant differences after open or laparoscopic surgery . CONCLUSIONS Our findings indicate a less pronounced proinflammatory response to surgical trauma in patients after minimally invasive surgery . The nonspecific immune response appears to be less affected by laparoscopic surgery when compared with open surgery while the specific cell-mediated immunity is equally affected . These findings are important because a divergent effect on specific and nonspecific immunity of laparoscopic surgery for colorectal disease has not been reported before 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 UNLABELLED This r and omized prospect i ve study compared the effectiveness of laparoscopic paraumbilical hernioplasty to the conventional open technique . Forty patients with paraumbilical hernia were r and omly categorized into 2 equal groups . GL treated by laparoscopic paraumbilical hernioplasty and GO treated by conventional ( open ) umbilical hernioplasty . The mean length of follow up was 36 months . In GL , mean operative time was 58.1 + /- 15.5 minutes , in GO , it was 42.2 + /- 10.3 minutes ( p = 0.0005 ) . Postoperative pain score 6 hours after surgery was 2.95 + /- 1.19 in GL patients as compared to 6.10 + /- 1.74 in GO ones ( p < 0.0001 ) . Mean hospitalization time was 1.05 + /- 0.224 days in GL versus 1.25 + /- 0.550 days in G O ( p = 0.14 ) . There was one conversion ( 5 % ) to the open repair . Postoperative seroma occurred in 2 patients ( 10 % ) in GL and 3 patients ( 15 % ) in GO . Three patients ( 15 % ) in G O developed surgical site infection . Hernia recurrence was not seen in either 2 Groups . Mean patient satisfaction score for GL patients was 7.85 + /- 1.27 versus 6.00 + /- 1.69 for GO patients ( p = 0.0004 ) . CONCLUSION Compared to open repair , laparoscopic repair is technically feasible , safe and effective , with good clinical outcome . It is associated with longer time for surgery but reduced postoperative pain , analgesic requirement , complication and infection rates with earlier return to normal activities Laparoscopic mesh repair has been advocated as the treatment of choice for ventral hernias [ 1 ] . In the case of umbilical and paraumbilical herniae , the role of laparoscopic hernioplasty , at present , remains unproven . A Medline literature search supports the thought that no firm consensus currently exists on the best technique for primary repair of these herniae . A Medline search identified two prospect i ve and two retrospective studies conducted within the last 6 years [ 1–4 ] . Furthermore , an EAES consensus meeting recommended open mesh , suture , or laparoscopic repair for defects \3 cm [ 5 ] . Although ventral hernia repair is increasingly performed laparoscopically , complication rates with this procedure are not well characterized [ 2 ] . The case for laparoscopic repair of (para)umbilical hernia is convincing . (Para)umbilical herniae have historically been repaired without mesh result ing in recurrence rates in some series of up to 54 % [ 6 , 7 ] . The use of prosthetic material for open umbilical hernia repair has been reported to reduce recurrence rates [ 3 , 4 ] . Ideal placement of the mesh is behind the defect , in the sub-lay position , which would be more difficult to achieve in an open approach , unless performed laparoscopically . Laparoscopic in-lay patch hernioplasty has been shown to be a safe and efficacious technique for the repair of (para)umbilical hernia [ 8 ] . The laparoscopic approach potentially confers the advantages of reduced recurrence rates , postoperative pain , shorter hospital stay , and a diminished morbidity rate [ 2 , 4 ] . Potential disadvantages include comparatively prolonged operative time and operator experience relating to the laparoscopic approach to these repairs . We set out to audit all primary (para)umbilical herniae repairs performed at our center during the past ten years to determine the differences in outcome and complication rates between open and laparoscopic repair Objective To evaluate the efficacy and safety of laparoscopic repair of ventral hernias .  Summary Background Data The recurrence rate after st and ard repair of ventral hernias may be as high as 12–52 % , and the wide surgical dissection required often results in wound complications . Use of a laparoscopic approach may decrease rates of complications and recurrence after ventral hernia repair . Methods Data on all patients who underwent laparoscopic ventral hernia repair ( LVHR ) performed by 4 surgeons using a st and ardized procedure between November 1993 and October 2002 were collected prospect ively ( 85 % of patients ) or retrospectively . Results LVHR was completed in 819 of the 850 patients ( 422 men ; 428 women ) in whom it was attempted . Thirty-four percent of completed LVHRs were for recurrent hernias . The patient mean body mass index was 32 ; the mean defect size was 118 cm2 . Mesh , averaging 344 cm2 , was used in all cases . Mean operating time was 120 min , mean estimated blood loss was 49 mL , and hospital stay averaged 2.3 days . There were 128 complications in 112 patients ( 13.2 % ) . One patient died of a myocardial infa rct ion . The most common complications were ileus ( 3 % ) and prolonged seroma ( 2.6 % ) . During a mean follow-up time of 20.2 months ( range , 1–94 months ) , the hernia recurrence rate was 4.7 % . Recurrence was associated with large defects , obesity , previous open repairs , and perioperative complications . Conclusion In this large series , LVHR had a low rate of conversion to open surgery , a short hospital stay , a moderate complication rate , and a low risk of recurrence Background Incisional hernia is an important complication of abdominal surgery . Its repair has progressed from a primary suture repair to various mesh repairs and laparoscopic repair . Laparoscopic mesh repair is a promising alternative , and in the absence of consensus , needs prospect i ve r and omized controlled trials . Methods Between April 2003 and April 2005 , 66 patients with incisional , primary ventral and recurrent hernias were r and omized to receive either open retrorectus mesh repair or laparoscopic mesh repair .  These patients were followed up at 1- , 3- , and 6-month intervals thereafter for a mean of 12.17 months ( open repair group ) and 13.73 months ( laparoscopic repair group ) . Results Lower abdominal hernias after gynecologic operations constituted the majority of the hernias ( ∼50 % ) in both groups . There was no significant injury to viscera or vessel in either group and no conversions . The defect size was 42.12 cm2 in the open ( group 1 ) and 65.66 cm2 in the laparoscopic group ( group 2 ) , and the prosthesis sizes were , respectively , 152.67 cm2 and 203.83 cm2 . The hospital stay was 3.43 days in open group and 1.47 days in laparoscopic group ( p = 0.007 ) . There was no significant difference in the pain scores between the two groups . More wound-related infectious complications occurred in the open group ( 33 % ) than in the laparoscopic group ( 6 % ) ( p = 0.013 ) . There was one recurrence in the open repair group ( 3 % ) and two recurrences in laparoscopic group ( 6 % ) ( p = 0.55 ) . Conclusions Laparoscopic repair of incisional and ventral hernias is superior to open mesh repair in terms of significantly less blood loss , fewer complications , shorter hospital stay , and excellent cosmetic outcome Background Approximately 175,000  umbilical hernia repairs  are performed annually in the US . Controversy exists regarding the optimal approach for the elective repair of primary umbilical hernias . Objective The objective of this study was to compare 30-day outcomes of  elective primary open ( OHR ) and laparoscopic ( LHR ) umbilical hernia repairs  , using a prospect ively collected data set . Methods We performed a retrospective cohort study using the American College of Surgeons National Surgery Quality Improvement Program Participant Use Files during 2009 and 2010 . Current Procedural Terminology and post-operative International Classification of Diseases , Ninth Revision diagnostic codes were used to identify primary umbilical hernia repairs . Primary outcomes included composite endpoints of 30-day mortality , and major and overall complications . Univariate analyses and multivariate logistic regression were performed controlling for relevant patient characteristics . Secondary outcomes included operative time and hospital length of stay ( LOS ) . Results Overall , 14,652 patients were identified—13,109 ( 89.5 % ) OHR and 1543 ( 10.5 % ) LHR . Univariate analyses of primary outcomes demonstrated similar 30-day morbidity and mortality between groups . In our multivariate model , however , after controlling for body mass index , gender , American Society of Anesthesiologists class , and chronic obstructive pulmonary disease , the odds ratio ( OR ) for overall complications favored LHR ( OR 0.60 ; p = 0.01 ) . This difference was driven primarily by the reduced wound 
    Output:
    
Conclusions The best available evidence ( r and omised and non-r and omised studies ) suggests that laparoscopic  repair of umbilical or paraumbilical hernias may be associated with a lower risk of wound infection , wound dehiscence and recurrence rate , shorter length of stay but longer operative time .
Results from a limited number of RCTs showed no difference in recurrence rates .