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Meta-Analysis
. 2017 Jun 21;6(6):CD009569.
doi: 10.1002/14651858.CD009569.pub3.

Gases for establishing pneumoperitoneum during laparoscopic abdominal surgery

Tianwu Yu  1 , Yao Cheng, Xiaomei Wang, Bing Tu, Nansheng Cheng, Jianping Gong, Lian Bai
Affiliations
Meta-Analysis

Gases for establishing pneumoperitoneum during laparoscopic abdominal surgery

Tianwu Yu et al. Cochrane Database Syst Rev. .

Update in

Abstract

Background: This is an update of the review published in 2013.Laparoscopic surgery is now widely performed to treat various abdominal diseases. Currently, carbon dioxide is the most frequently used gas for insufflation of the abdominal cavity (pneumoperitoneum). Although carbon dioxide meets most of the requirements for pneumoperitoneum, the absorption of carbon dioxide may be associated with adverse events. People with high anaesthetic risk are more likely to experience cardiopulmonary complications and adverse events, for example hypercapnia and acidosis, which has to be avoided by hyperventilation. Therefore, other gases have been introduced as alternatives to carbon dioxide for establishing pneumoperitoneum.

Objectives: To assess the safety, benefits, and harms of different gases (i.e. carbon dioxide, helium, argon, nitrogen, nitrous oxide, and room air) used for establishing pneumoperitoneum in participants undergoing laparoscopic general abdominal or gynaecological pelvic surgery.

Search methods: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2016, Issue 9), Ovid MEDLINE (1950 to September 2016), Ovid Embase (1974 to September 2016), Science Citation Index Expanded (1970 to September 2016), Chinese Biomedical Literature Database (CBM) (1978 to September 2016), ClinicalTrials.gov (September 2016), and World Health Organization International Clinical Trials Registry Platform (September 2016).

Selection criteria: We included randomised controlled trials (RCTs) comparing different gases for establishing pneumoperitoneum in participants (irrespective of age, sex, or race) undergoing laparoscopic abdominal or gynaecological pelvic surgery under general anaesthesia.

Data collection and analysis: Two review authors identified the trials for inclusion, collected the data, and assessed the risk of bias independently. We performed the meta-analyses using Review Manager 5. We calculated risk ratio (RR) for dichotomous outcomes (or Peto odds ratio for very rare outcomes), and mean difference (MD) or standardised mean difference (SMD) for continuous outcomes with 95% confidence intervals (CI). We used GRADE to rate the quality of evidence, MAIN RESULTS: We included nine RCTs, randomising 519 participants, comparing different gases for establishing pneumoperitoneum: nitrous oxide (three trials), helium (five trials), or room air (one trial) was compared to carbon dioxide. Three trials randomised participants to nitrous oxide pneumoperitoneum (100 participants) or carbon dioxide pneumoperitoneum (96 participants). None of the trials was at low risk of bias. There was insufficient evidence to determine the effects of nitrous oxide and carbon dioxide on cardiopulmonary complications (RR 2.00, 95% CI 0.38 to 10.43; two studies; 140 participants; very low quality of evidence), or surgical morbidity (RR 1.01, 95% CI 0.18 to 5.71; two studies; 143 participants; very low quality of evidence). There were no serious adverse events related to either nitrous oxide or carbon dioxide pneumoperitoneum (three studies; 196 participants; very low quality of evidence). We could not combine data from two trials (140 participants) which individually showed lower pain scores (a difference of about one visual analogue score on a scale of 1 to 10 with lower numbers indicating less pain) with nitrous oxide pneumoperitoneum at various time points on the first postoperative day, and this was rated asvery low quality .Four trials randomised participants to helium pneumoperitoneum (69 participants) or carbon dioxide pneumoperitoneum (75 participants) and one trial involving 33 participants did not state the number of participants in each group. None of the trials was at low risk of bias. There was insufficient evidence to determine the effects of helium or carbon dioxide on cardiopulmonary complications (RR 1.46, 95% CI 0.35 to 6.12; three studies; 128 participants; very low quality of evidence) or pain scores (visual analogue score on a scale of 1 to 10 with lower numbers indicating less pain; MD 0.49 cm, 95% CI -0.28 to 1.26; two studies; 108 participants; very low quality of evidence). There were three serious adverse events (subcutaneous emphysema) related to helium pneumoperitoneum (three studies; 128 participants; very low quality of evidence).One trial randomised participants to room air pneumoperitoneum (70 participants) or carbon dioxide pneumoperitoneum (76 participants). The trial was at unclear risk of bias. There were no cardiopulmonary complications or serious adverse events observed related to either room air or carbon dioxide pneumoperitoneum (both outcomes very low quality of evidence). The evidence of lower hospital costs and reduced pain during the first postoperative day with room air pneumoperitoneum compared with carbon dioxide pneumoperitoneum (a difference of about one visual analogue score on a scale of 1 to 10 with lower numbers indicating less pain, was rated as very low quality of evidence.

Authors' conclusions: The quality of the current evidence is very low. The effects of nitrous oxide and helium pneumoperitoneum compared with carbon dioxide pneumoperitoneum are uncertain. Evidence from one trial of small sample size suggests that room air pneumoperitoneum may decrease hospital costs in people undergoing laparoscopic abdominal surgery. The safety of nitrous oxide, helium, and room air pneumoperitoneum has yet to be established.Further trials on this topic are needed, and should compare various gases (i.e. nitrous oxide, helium, argon, nitrogen, and room air) with carbon dioxide under standard pressure pneumoperitoneum with cold gas insufflation for people with high anaesthetic risk. Future trials should include outcomes such as complications, serious adverse events, quality of life, and pain.

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Conflict of interest statement

None declared.

Figures

1
1
Study flow diagram.
2
2
Risk of bias graph: review authors' judgements about each risk of bias item presented as percentages across all included studies.
3
3
Risk of bias summary: review authors' judgements about each risk of bias item for each included study.
4
4
Trial sequential analysis of nitrous oxide pneumoperitoneum versus carbon dioxide pneumoperitoneum for cardiopulmonary complications. Analysis was performed with an event rate of 2.9% (Pc) in the control group, a risk ratio reduction of 20%, alpha 5%, beta 20%, and observed diversity 0%. The accrued sample size was so small that the trial sequential boundaries could not be drawn. The cumulative Z‐curve did not cross the naive 5% statistical boundaries (red horizontal lines). The results showed that the observed diversity‐adjusted required information size was 3781 participants, corresponding to 3.7% of the total sample size in the included trials. Accordingly, the meta‐analysis did not support or refute an intervention effect as data were too few.
5
5
Trial sequential analysis of nitrous oxide pneumoperitoneum versus carbon dioxide pneumoperitoneum for surgical morbidity. Analysis was performed with an event rate of 2.8% (Pc) in the control group, a risk ratio reduction of 20%, alpha 5%, beta 20%, and observed diversity 0%. The cumulative Z‐curve did not cross the naive 5% statistical boundaries (red horizontal lines). The results showed that the observed diversity adjusted required information size was 3919 participants, corresponding to 3.6% of the total sample size in the included trials. Accordingly, the meta‐analysis did not support or refute an intervention effect as data were too few.
6
6
Trial sequential analysis of helium pneumoperitoneum versus carbon dioxide pneumoperitoneum for cardiopulmonary complications. Analysis was performed with an event rate of 3.0% (Pc) in the control group, a risk ratio reduction of 20%, alpha 5%, beta 20%, and observed diversity 0%. The cumulative Z‐curve did not cross the naive 5% statistical boundaries (red horizontal lines). The results showed that the observed diversity adjusted required information size was 3651 participants, corresponding to 3.5% of the total sample size in the included trials. Accordingly, the meta‐analysis did not support or refute an intervention effect as data were too few.
7
7
Trial sequential analysis of helium pneumoperitoneum versus carbon dioxide pneumoperitoneum for serious adverse events. Analysis was performed with an event rate of 2.3% (Pc) in the control group, a risk ratio reduction of 20%, alpha 5%, beta 20%, and observed diversity 0%. The cumulative Z‐curve did not cross the naive 5% statistical boundaries (red horizontal lines). The results showed that the observed diversity adjusted required information size was 4793 participants, corresponding to 2.7% of the total sample size in the included trials. Accordingly, the meta‐analysis did not support or refute an intervention effect as data were too few.
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Update of

References

References to studies included in this review

Aitola 1998 {published data only}
    1. Aitola P, Airo I, Kaukinen S, Ylitalo P. Comparison of N2O and CO2 pneumoperitoneums during laparoscopic cholecystectomy with special reference to postoperative pain. Surgical Laparoscopy Endoscopy 1998;8(2):140‐4. - PubMed
Bongard 1993 {published data only}
    1. Bongard FS, Pianim NA, Leighton TA, Dubecz S, Davis IP, Lippmann M, et al. Helium insufflation for laparoscopic operation. Surgery Gynecology & Obstetrics 1993;177(2):140‐6. - PubMed
Gu 2015 {published data only}
    1. Gu Y, Wu W. Clinical application value of air insufflation medium under laparoscopic cholecystectomy [空气膨腹介质下腹腔镜胆囊切除术的临床应用价值]. Chinese and Foreign Medical Research 2015;13(1):8‐9.
Lipscomb 1993 {published data only}
    1. Lipscomb GH, Stovall TG, Summitt RL Jr, Ling FW. The effect of nitrous oxide and carbon dioxide pneumoperitoneum on post laparoscopy tubal ligation pain. Journal of Gynecologic Surgery 1993;9(3):175‐8.
Naude 1996 {published data only}
    1. Naude GP, Ryan MK, Pianim NA, Klein SR, Lippmann M, Bongard FS. Comparative stress hormone changes during helium versus carbon dioxide laparoscopic cholecystectomy. Journal of Laparoendoscopic Surgery 1996;6(2):93‐8. - PubMed
Neuhaus 2001 {published data only}
    1. Neuhaus SJ, Watson DI, Ellis T, Lafullarde T, Jamieson GG, Russell WJ. Metabolic and immunologic consequences of laparoscopy with helium or carbon dioxide insufflation: a randomized clinical study. ANZ Journal of Surgery 2001;71(8):447‐52. - PubMed
O'Boyle 2002 {published data only}
    1. O'Boyle CJ, deBeaux AC, Watson DI, Ackroyd R, Lafullarde T, Leong JY, et al. Helium vs carbon dioxide gas insufflation with or without saline lavage during laparoscopy. Surgical Endoscopy 2002;16(4):620‐5. - PubMed
Sietses 2002 {published data only}
    1. Sietses C, von Blomberg ME, Eijsbouts QA, Beelen RH, Berends FJ, Cuesta MA. The influence of CO2 versus helium insufflation or the abdominal wall lifting technique on the systemic immune response. Surgical Endoscopy 2002;16(3):525‐8. - PubMed
Tsereteli 2002 {published data only}
    1. Tsereteli Z, Terry ML, Bowers SP, Spivak H, Archer SB, Galloway KD, et al. Prospective randomized clinical trial comparing nitrous oxide and carbon dioxide pneumoperitoneum for laparoscopic surgery. Journal of the American College of Surgeons 2002;195(2):173‐9. - PubMed

References to studies excluded from this review

Fernández‐Cruz 1998 {published data only}
    1. Fernández‐Cruz L, Sáenz A, Taurá P, Sabater L, Astudillo E, Fontanals J. Helium and carbon dioxide pneumoperitoneum in patients with pheochromocytoma undergoing laparoscopic adrenalectomy. World Journal of Surgery 1998;22(12):1250‐5. - PubMed
Lipscomb 1994 {published data only}
    1. Lipscomb GH, Summitt RL Jr, McCord ML, Ling FW. The effect of nitrous oxide and carbon dioxide pneumoperitoneum on operative and postoperative pain during laparoscopic sterilization under local anesthesia. Journal of the American Association of Gynecologic Laparoscopists 1994;2(1):57‐60. - PubMed
McMahon 1994 {published data only}
    1. McMahon AJ, Baxter JN, Murray W, Imrie CW, Kenny G, O'Dwyer PJ. Helium pneumoperitoneum for laparoscopic cholecystectomy: ventilatory and blood gas changes. British Journal of Surgery 1994;81(7):1033‐6. - PubMed
Neuberger 1996 {published data only}
    1. Neuberger TJ, Andrus CH, Wittgen CM, Wade TP, Kaminski DL. Prospective comparison of helium versus carbon dioxide pneumoperitoneum. Gastrointestinal Endoscopy 1996;43(1):38‐41. - PubMed
Ooka 1993 {published data only}
    1. Ooka T, Kawano Y, Kosaka Y, Tanaka A. Blood gas changes during laparoscopic cholecystectomy ‐ comparative study of N2O pneumoperitoneum and CO2 pneumoperitoneum. Masui. The Japanese Journal of Anesthesiology 1993;42(3):398‐401. - PubMed
Rammohan 2011 {published data only}
    1. Rammohan A, Manimaran AB, Manohar RR, Naidu RM. Nitrous oxide for pneumoperitoneum: no laughing matter this! A prospective single blind case controlled study. International Journal of Surgery (London, England) 2011;9(2):173‐6. - PubMed
Sharp 1982 {published data only}
    1. Sharp JR, Pierson WP, Brady CE 3rd. Comparison of CO2‐ and N2O‐induced discomfort during peritoneoscopy under local anesthesia. Gastroenterology 1982;82(3):453‐6. - PubMed

References to studies awaiting assessment

Bergstrom 2015 {published data only}
    1. Bergstrom M, Park PO, Falk P, Haglind E, Holmdahl L. Clinical evaluation of peritoneal acidification and fibrinolytic response during laparoscopy comparing CO2 and helium. Surgical Endoscopy and Other Interventional Techniques 2015;29:S527.

References to ongoing studies

Asgari 2012 {published data only}
    1. Prospective randomised trial comparing nitrous oxide and carbon dioxide for laparoscopic cholecystectomy.. Ongoing study November 2010..

Additional references

Aboumarzouk 2011
    1. Aboumarzouk OM, Agarwal T, Syed Nong Chek SAH, Milewski PJ, Nelson RL. Nitrous oxide for colonoscopy. Cochrane Database of Systematic Reviews 2011, Issue 8. [DOI: 10.1002/14651858.CD008506.pub2] - DOI - PubMed
Ahmad 2015
    1. Ahmad G, Gent D, Henderson D, O'Flynn H, Phillips K, Watson A. Laparoscopic entry techniques. Cochrane Database of Systematic Reviews 2015, Issue 8. [DOI: 10.1002/14651858.CD006583.pub4] - DOI - PubMed
Andersen 2015
    1. Andersen HK. Cochrane Colorectal Cancer Group. About The Cochrane Collaboration (Cochrane Review Groups (CRGs)) 2015, Issue 3. Art. No.: COLOCA.
Antoniou 2015
    1. Antoniou SA, Antoniou GA, Antoniou AI, Granderath FA. Past, present, and future of minimally invasive abdominal surgery. Journal of the Society of Laparoendoscopic Surgeons 2015;13(29):e2015.00052. - PMC - PubMed
Best 2016
    1. Best LMJ, Mughal M, Gurusamy KS. Laparoscopic versus open gastrectomy for gastric cancer. Cochrane Database of Systematic Reviews 2016, Issue 3. [DOI: 10.1002/14651858.CD011389.pub2] - DOI - PMC - PubMed
Birch 2016
    1. Birch DW, Dang, JT, Switzer NJ, Manouchehri N, Shi X, Hadi G, et al. Heated insufflation with or without humidification for laparoscopic abdominal surgery. Cochrane Database of Systematic Reviews 2016, Issue 10. [DOI: 10.1002/14651858.CD007821.pub3] - DOI - PMC - PubMed
Brok 2008
    1. Brok J, Thorlund K, Gluud C, Wetterslev J. Trial sequential analysis reveals insufficient information size and potentially false positive results in many meta‐analyses. Journal of Clinical Epidemiology 2008;61(8):763‐9. - PubMed
Cai 2014
    1. Cai Y, Liu Z, Liu X. Laparoscopic versus open splenectomy for portal hypertension: a systematic review of comparative studies. Surgical Innovation 2014;21(4):442‐7. - PubMed
Cheng 2012a
    1. Cheng Y, Xiong XZ, Wu SJ, Lin YX, Cheng NS. Laparoscopic vs. open cholecystectomy for cirrhotic patients: a systematic review and meta‐analysis. Hepato‐gastroenterology 2012;59(118):1727‐34. - PubMed
Cheng 2012b
    1. Cheng Y, Xiong XZ, Wu SJ, Lu J, Lin YX, Cheng NS, et al. Carbon dioxide insufflation for endoscopic retrograde cholangiopancreatography: a meta‐analysis and systematic review. World Journal of Gastroenterology 2012;18(39):5622‐31. - PMC - PubMed
Cheng 2013
    1. Cheng Y, Lu J, Xiong X, Wu S, Lin Y, Wu T, et al. Gases for establishing pneumoperitoneum during laparoscopic abdominal surgery. Cochrane Database of Systematic Reviews 2013, Issue 1. [DOI: 10.1002/14651858.CD009569.pub2] - DOI - PubMed
Cheng 2015
    1. Cheng Y, Zhou S, Zhou R, Lu J, Wu S, Xiong X, et al. Abdominal drainage to prevent intra‐peritoneal abscess after open appendectomy for complicated appendicitis. Cochrane Database of Systematic Reviews 2015, Issue 2. [DOI: 10.1002/14651858.CD010168.pub2] - DOI - PubMed
Cheng 2016
    1. Cheng Y, Xia J, Lai M, Cheng N, He S. Prophylactic abdominal drainage for pancreatic surgery. Cochrane Database of Systematic Reviews 2016, Issue 10. [DOI: 10.1002/14651858.CD010583.pub3] - DOI - PMC - PubMed
Clavien 2009
    1. Clavien PA, Barkun J, Oliveira ML, Vauthey JN, Dindo D, Schulick RD, et al. The Clavien‐Dindo classification of surgical complications: five‐year experience. Annals of Surgery 2009;250(2):187‐96. - PubMed
Dasari 2011
    1. Dasari BVM, McKay D, Gardiner K. Laparoscopic versus open surgery for small bowel Crohn's disease. Cochrane Database of Systematic Reviews 2011, Issue 1. [DOI: 10.1002/14651858.CD006956.pub2] - DOI - PubMed
Deeks 2011
    1. Deeks JJ, Higgins JPT, Altman DG. Chapter 9: Analysing data and undertaking meta‐analyses. In: Higgins JPT, Green S, editor(s). Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 (updated March 2011). The Cochrane Collaboration, 2011. Available from handbook.cochrane.org.
Eaton 2009
    1. Eaton S, McHoney M, Giacomello L, Pacilli M, Bishay M, Coppi P, et al. Carbon dioxide absorption and elimination in breath during minimally invasive surgery. Journal of Breath Research 2009;3(4):047005. - PubMed
El‐Kady 1976
    1. El‐Kady AA, Abd‐El‐Razek M. Intraperitoneal explosion during female sterilization by laparoscopic electrocoagulation. A case report. International Journal of Gynecology & Obstetrics 1976;14(6):487‐8. - PubMed
Gardner 1995
    1. Gardner JG, Trus TL, Laycock WS, Hunter JG. Converting from carbon dioxide to nitrous oxide pneumoperitoneum. Surgical Endoscopy 1995;9(9):1034‐5. - PubMed
Grabowski 2009
    1. Grabowski JE, Talamini MA. Physiological effects of pneumoperitoneum. Journal of Gastrointestinal Surgery 2009;13(5):1009‐16. - PubMed
Gunatilake 1978
    1. Gunatilake DE. Case report: fatal intraperitoneal explosion during electrocoagulation via laparoscopy. International Journal of Gynaecology and Obstetrics 1978;15(4):353‐7. - PubMed
Gurusamy 2014
    1. Gurusamy KS, Vaughan J, Davidson BR. Low pressure versus standard pressure pneumoperitoneum in laparoscopic cholecystectomy. Cochrane Database of Systematic Reviews 2014, Issue 3. [DOI: 10.1002/14651858.CD006930.pub3] - DOI - PMC - PubMed
Gutt 2004
    1. Gutt CN, Oniu T, Mehrabi A, Schemmer P, Kashfi A, Kraus T, et al. Circulatory and respiratory complications of carbon dioxide insufflation. Digestive Surgery 2004;21(2):95‐105. - PubMed
Higgins 2011a
    1. Higgins JPT, Green S, editor(s). Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 (updated March 2011). The Cochrane Collaboration, 2011. Available from handbook.cochrane.org.
Higgins 2011b
    1. Higgins JPT, Deeks JJ. Chapter 7: Selecting studies and collecting data. In: Higgins JPT, Green S, editor(s), Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 (updated March 2011). The Cochrane Collaboration, 2011. Available from handbook.cochrane.org.
Higgins 2011c
    1. Higgins JPT, Altman DG, Sterne JAC. Chapter 8: Assessing risk of bias in included studies. In: Higgins JPT, Green S, editor(s). Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 (updated March 2011). The Cochrane Collaboration, 2011. Available from handbook.cochrane.org.
Hunter 1995
    1. Hunter JG, Staheli J, Oddsdottir M, Trus T. Nitrous oxide pneumoperitoneum revisited. Is there a risk of combustion?. Surgical Endoscopy 1995;9(5):501‐4. - PubMed
Ikechebelu 2005
    1. Ikechebelu JI, Obi RA, Udigwe GO, Joe‐Ikechebelu NN. Comparison of carbon dioxide and room air pneumoperitoneum for day‐case diagnostic laparoscopy. Journal of Obstetrics and Gynaecology 2005;25(2):172‐3. - PubMed
Karapolat 2011
    1. Karapolat S, Gezer S, Yildirim U, Dumlu T, Karapolat B, Ozaydin I, et al. Prevention of pulmonary complications of pneumoperitoneum in rats. Journal of Cardiothoracic Surgery 2011;6(14):1‐7. - PMC - PubMed
Katz 2015
    1. Katz NP, Paillard FC, Ekman E. Determining the clinical importance of treatment benefits for interventions for painful orthopedic conditions. Journal of Orthopaedic Surgery and Research 2015;10:24. - PMC - PubMed
Keus 2006
    1. Keus F, Jong J, Gooszen HG, Laarhoven CJHM. Laparoscopic versus open cholecystectomy for patients with symptomatic cholecystolithiasis. Cochrane Database of Systematic Reviews 2006, Issue 4. [DOI: 10.1002/14651858.CD006231] - DOI - PubMed
Kuhry 2008
    1. Kuhry E, Schwenk W, Gaupset R, Romild U, Bonjer HJ. Long‐term results of laparoscopic colorectal cancer resection. Cochrane Database of Systematic Reviews 2008, Issue 2. [DOI: 10.1002/14651858.CD003432.pub2] - DOI - PMC - PubMed
Kwak 2010
    1. Kwak HJ, Jo YY, Lee KC, Kim YB, Shinn HK, Kim J. Acid‐base alterations during laparoscopic abdominal surgery: a comparison with laparotomy. British Journal of Anaesthesia 2010;105(4):442‐7. - PubMed
Menes 2000
    1. Menes T, Spivak H. Laparoscopy: searching for the proper insufflation gas. Surgical Endoscopy 2000;14(11):1050‐6. - PubMed
Nabi 2016
    1. Nabi G, Cleves A, Shelley M. Surgical management of localised renal cell carcinoma. Cochrane Database of Systematic Reviews 2016, Issue 3. [DOI: 10.1002/14651858.CD006579.pub3] - DOI - PMC - PubMed
Neudecker 2002
    1. Neudecker J, Sauerland S, Neugebauer E, Bergamaschi R, Bonjer HJ, Cuschieri A, et al. The European Association for Endoscopic Surgery clinical practice guideline on the pneumoperitoneum for laparoscopic surgery. Surgical Endoscopy 2002;16(7):1121‐43. - PubMed
Neuman 1993
    1. Neuman GG, Sidebotham G, Negoianu E, Bernstein J, Kopman AF, Hicks RG, et al. Laparoscopy explosion hazards with nitrous oxide. Anesthesiology 1993;78(5):875‐9. - PubMed
Parker 2013
    1. Parker SL, Godil SS, Shau DN, Mendenhall SK, McGirt MJ. Assessment of the minimum clinically important difference in pain, disability, and quality of life after anterior cervical discectomy and fusion: clinical article. Journal of Neurosurgery. Spine 2013;18(2):154‐60. - PubMed
Rao 2013
    1. Rao AM, Ahmed I. Laparoscopic versus open liver resection for benign and malignant hepatic lesions in adults. Cochrane Database of Systematic Reviews 2013, Issue 5. [DOI: 10.1002/14651858.CD010162.pub2] - DOI - PMC - PubMed
RevMan 2014 [Computer program]
    1. The Nordic Cochrane Centre, The Cochrane Collaboration. Review Manager (RevMan). Version 5.3. Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, 2014.
Riviere 2016
    1. Riviere D, Gurusamy KS, Kooby DA, Vollmer CM, Besselink MGH, Davidson BR, et al. Laparoscopic versus open distal pancreatectomy for pancreatic cancer. Cochrane Database of Systematic Reviews 2016, Issue 4. [DOI: 10.1002/14651858.CD011391.pub2] - DOI - PMC - PubMed
Sammour 2009
    1. Sammour T, Mittal A, Loveday BP, Kahokehr A, Phillips AR, Windsor JA, et al. Systematic review of oxidative stress associated with pneumoperitoneum. British Journal of Surgery 2009;96(8):836‐50. - PubMed
Sanabria 2013
    1. Sanabria A, Villegas MI, Morales Uribe CH. Laparoscopic repair for perforated peptic ulcer disease. Cochrane Database of Systematic Reviews 2013, Issue 2. [DOI: 10.1002/14651858.CD004778.pub3] - DOI - PMC - PubMed
Sauerland 2010
    1. Sauerland S, Jaschinski T, Neugebauer EAM. Laparoscopic versus open surgery for suspected appendicitis. Cochrane Database of Systematic Reviews 2010, Issue 10. [DOI: 10.1002/14651858.CD001546.pub3] - DOI - PubMed
Schünemann 2009
    1. Schünemann H, Brozek J, Oxman A, editors. GRADE handbook for grading quality of evidence and strength of recommendations. Version 3.2 (updated March 2009). The GRADE Working Group, 2009. Available from www.cc‐ims.net/gradepro.
Spaner 1997
    1. Spaner SJ, Warnock GL. A brief history of endoscopy, laparoscopy, and laparoscopic surgery. Journal of Laparoendoscopic & Advanced Surgical Techniques. Part a 1997;7(6):369‐73. - PubMed
Sterne 2011
    1. Sterne JAC, Egger M, Moher D. Chapter 10: Addressing reporting biases. In: Higgins JPT, Green S (editors). Cochrane Handbook for Systematic Reviews of Intervention. Version 5.1.0 (updated March 2011). The Cochrane Collaboration, 2011. Available from handbook.cochrane.org.
Todd 1996
    1. Todd KH, Funk JP. The minimum clinically important difference in physician‐assigned visual analog pain scores. Academic Emergency Medicine 1996;3(2):142‐6. - PubMed
TSA 2011 [Computer program]
    1. Copenhagen Trial Unit. TSA ‐ Trial Sequential Analysis. Version 0.9.5.5 Beta. Copenhagen: Copenhagen Trial Unit, 2011.
Wetterslev 2008
    1. Wetterslev J, Thorlund K, Brok J, Gluud C. Trial sequential analysis may establish when firm evidence is reached in cumulative meta‐analysis. Journal of Clinical Epidemiology 2008;61(1):64‐75. - PubMed
Wetterslev 2009
    1. Wetterslev J, Thorlund K, Brok J, Gluud C. Estimating required information size by quantifying diversity in random‐effects model meta‐analyses. BMC Medical Research Methodology 2009;9:86. - PMC - PubMed

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