{"paper_id":"f6d27f41-e3cd-4857-a343-e5dd21af8f87","body_text":"Jul 21, 2025\nSystematic review and meta-analysis of outcomes following laparoscopic\nnerve decompression surgery in neuropathic sciatic pain due to\nendometriosis of the sacral plexus and/or sciatic nerve\nDOI\nhttps://dx.doi.org/10.17504/protocols.io.bp2l6zn5dgqe/v1\nCamilleRacca,JuliaFranken,AurellyCicchelero,MarionCahen\nHôpital Pitié Salpêtrière, APHP, Paris;Clinical Research Team, DRAW YOUR FIGHT, Paris\nCamille Racca: Principal investigator;\nJulia Franken: Co-investigator\nAurelly Cicchelero: Patient contributor involved in protocol design and outcome relevance assessment\nMarion Cahen: Scientific contributor\nCamille Racca\nHôpital de la Pitié Salpêtrière - APHP\nCreate & collaborate more with a free account\nEdit and publish protocols, collaborate in communities, share insights through comments, and\ntrack progress with run records.\nCreate free account\n1,2 2 2 1,2\n1 2\nDOI: https://dx.doi.org/10.17504/protocols.io.bp2l6zn5dgqe/v1\nprotocols.io | https://dx.doi.org/10.17504/protocols.io.bp2l6zn5dgqe/v1 July 21, 2025 1/11\n\nProtocolCitation: Camille Racca, Julia Franken, Aurelly Cicchelero, Marion Cahen2025. Systematic review and meta-analysis\nof outcomes following laparoscopic nerve decompression surgery in neuropathic sciatic pain due to endometriosis of the sacral\nplexus and/or sciatic nerve.protocols.iohttps://dx.doi.org/10.17504/protocols.io.bp2l6zn5dgqe/v1\nLicense:This is an open accessprotocoldistributed under the terms of theCreative Commons Attribution License,  which\npermits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited\nProtocol status:Working\nWe are currently using this protocol as part of an ongoing systematic review and meta-analysis. Data screening, extraction,\nand preliminary analyses are underway in accordance with the methods outlined here.\nCreated:July 19, 2025\nLast Modified:July 21, 2025\nProtocolInteger ID:222824\nKeywords: systematic review, meta-analysis, laparoscopic nerve decompression, neuropathic sciatic pain, endometriosis,\nsacral plexus, sciatic nerve, neuropathic pain, sciatica, laparoscopic nerve decompression surgery in neuropathic sciatic pain,\nneuropathic sciatic pain due to endometriosi, endometriosis of the sacral plexus, laparoscopic nerve decompression surgery in\npatient, following laparoscopic nerve decompression surgery, neuropathic sciatic pain, endometriosi, sciatic nerve, sciatic\nnerve abstract, sacral plexus, postoperative data on pain frequency, sparing surgical approach, nerve, safety of nerve\nAbstract\nAbstract \nThis systematic review and meta-analysis protocol aims to evaluate clinical outcomes following laparoscopic\nnerve decompression surgery in patients with neuropathic sciatic pain due to endometriosis involving the sacral\nplexus and/or sciatic nerve. The review will include studies published between 2000 and 2025 reporting pre- and\npostoperative data on pain frequency and intensity, quality of life, diagnostic delay, and surgical complications.\nWe expect this review to provide the first quantitative synthesis of outcomes associated with this severe and\nunderdiagnosed condition, helping clarify the effectiveness and safety of nerve-sparing surgical approaches. The\nresults may inform future clinical guidelines and highlight gaps in current evidence\nprotocols.io | https://dx.doi.org/10.17504/protocols.io.bp2l6zn5dgqe/v1 July 21, 2025 2/11\n\nGuidelines\nThis systematic review and meta-analysis protocol strictly follows internationally recognized methodological\nguidelines to ensure transparency, reproducibility, and scientific rigor.\nThe protocol is reported in accordance with the PRISMAP 2015 Preferred Reporting Items for Systematic\nreview and Meta-Analysis Protocols) guidelines.\nThe full review will follow the PRISMA 2020 statement to ensure clear and complete reporting of the\nsystematic review process.\nRisk of bias in individual studies will be assessed using the Joanna Briggs Institute JBI Critical Appraisal\nTools, adapted to each study design.\nThe certainty of evidence will be evaluated using the GRADE Grading of Recommendations, Assessment,\nDevelopment, and Evaluation) approach, when applicable.\nStatistical analysis will be conducted in line with recommendations from the Cochrane Handbook for\nSystematic Reviews of Interventions, including use of the restricted maximum likelihood REML) estimator and\nthe Hartung-Knapp-Sidik-Jonkman HKSJ) method for random-effects models.\nThe protocol will be registered in PROSPERO and adheres to its standards for prospective protocol registration\nof systematic reviews.\nThis protocol will be registered in PROSPERO and complies with its standards for the prospective registration\nof systematic review protocols.\nIn addition, the review protocol has undergone external peer review by independent experts in pain medicine\nand gynecology to ensure its clinical relevance, methodological soundness, and clarity of objectives prior to\nPROSPERO registration. The final results of the review will also be submitted for peer-reviewed publication in\na scientific journal.\nBefore start\nFamiliarize the team with PRISMAP and PRISMA 2020 guidelines.\nEnsure access to all required databases PubMed, Embase, Scopus, etc.).\nAssign at least one reviewer with statistical software skills R, Jamovi).\nprotocols.io | https://dx.doi.org/10.17504/protocols.io.bp2l6zn5dgqe/v1 July 21, 2025 3/11\n\nPopulation\n1 Exclude patients with one or more of the following criteria :\nPatients younger than 18 or older than 60 years of age;\nMale patients;\nPatients presenting with neuropathic pelvic pain without definitive diagnostic\nconfirmation of sciatic nerve and/or sacral plexus involvement;\nPatients with a history of traumatic neuropathic pelvic or sciatic pain prior to\ndiagnosis or surgical intervention;\nPatients presenting with non-neuropathic pelvic or lower limb pain;\nPatients without final diagnostic confirmation of the neuropathic origin through pelvic\nassessment (including pelvic ultrasound, pelvic MRI, neurography MRI, and/or pelvic\nelectromyography), intraoperative findings, or histological analysis;\nPatients diagnosed with endometriosis without associated neurological symptoms\n(i.e., no clinical signs suggestive of sciatic nerve or sacral plexus involvement);\nPatients who previously underwent pelvic nerve surgery for unrelated indications\n(e.g., trauma, oncological procedures);\nPatients who have not undergone laparoscopic nerve decompression surgery, with or\nwithout nerve-sparing techniques (including conventional laparoscopic surgery,\nLANN technique, or robotic-assisted approaches).\n2 Include women meeting all of the following criteria : \nAged 18 to 60 years;\nPresenting with neuropathic sciatic pain in a clinical context suggestive of\nendometriosis involving the sciatic nerve and/or sacral plexus;\nUnderwent laparoscopic nerve decompression surgery, with or without nerve-sparing\ntechniques (including conventional laparoscopic surgery, LANN technique, or robotic-\nassisted approaches);\nFinal diagnosis confirmed by pelvic assessment (including pelvic ultrasound, pelvic\nMRI, neurography MRI, or pelvic electromyography), intraoperative findings, or\nhistological confirmation.\nIntervention\n3 Include studies that meet all of the following criteria : \nLaparoscopic surgical approach, excluding primary open laparotomy or transgluteal\napproaches ; \nTargeted decompression of the sciatic nerve and/or the sacral plexus; \nSurgery performed in the context of suspected or confirmed sciatic endometriosis,\nbased on clinical symptoms and/or diagnostic confirmation through pelvic\nassessment (including pelvic ultrasound, pelvic MRI, neurography MRI, or\nelectromyography).\nprotocols.io | https://dx.doi.org/10.17504/protocols.io.bp2l6zn5dgqe/v1 July 21, 2025 4/11\n\n4 Additional specifications : \nTechniques reviewed include conventional laparoscopy, nerve-sparing procedures\nsuch as the Laparoscopic Neuronavigation LANN) technique, and robotic-assisted\napproaches. \nConcomitant surgical procedures (such as hysterectomy or excision of other pelvic\nlesions) do not constitute exclusion criteria, provided that decompression of the\nsciatic nerve and/or the sacral plexus was part of the surgical intervention. \nPartial excision of the affected nerve segment, when required due to endometriotic\ninfiltration, is considered an integral part of the procedure and does not lead to\nexclusion. \nAdditional decompression of other pelvic nerves, such as the pudendal nerve, is also\npermitted as long as decompression of the sciatic nerve and/or the sacral plexus was\nperformed during the same intervention.\n5 Exclude studies if one or more of the following conditions apply : \nPrimary non-laparoscopic surgical approaches (e.g. initial open laparotomy or\ntransgluteal access) ; \nSurgical procedures not involving decompression of the sciatic nerve, the sacral\nplexus, or their contributing roots (e.g., L4 to S3 ; \nSurgeries performed for non-neurological indications, such as endometriosis without\nneuropathic pain;\nSurgical interventions targeting only other pelvic nerves, without concomitant\ndecompression of the sciatic nerve, the sacral plexus, or their contributing roots.\nType of study\n6 Include original clinical studies reporting relevant outcomes related to the surgical\ndecompression of the sciatic nerve and/or the sacral plexus in the context of\nendometriosis, published in French or in English. \n.\nConsider the following designs for inclusion : \nProspective cohort studies, including both observational and interventional designs ; \nRetrospective cohort studies and case series involving five or more patients, provided\nthey report sufficient clinical and surgical details ; \nRandomized controlled trials RCTs, if available ; \nMixed-methods studies, if they include extractable clinical data relevant to the\nsurgical intervention ;\nInclude conference abstracts, provided that adequate data are available for\nextraction.\n7 To be eligible, studies must report pre- and post-operative data on the frequency of\nneuropathic sciatic pain, as defined in the primary outcome. Only studies published\nbetween January 1, 2000, and July 1, 2025 will be considered for inclusion.\nprotocols.io | https://dx.doi.org/10.17504/protocols.io.bp2l6zn5dgqe/v1 July 21, 2025 5/11\n\n8 Exclude the following sources: \nDuplicate publications (e.g., multiple reports based on the same patient cohort) ; \nSingle-case reports; \nCase series involving four or fewer patients; \nEditorials, expert opinions, and narrative or literature reviews; \nTheoretical or methodological papers that do not report original clinical data; \nAnimal or preclinical studies; studies without extractable outcome data, even if the\nintervention is described (e.g., surgical technique videos without clinical results).\nSearch strategy\n9 Conduct a comprehensive literature search across multiple electronic databases to\nidentify relevant studies evaluating laparoscopic nerve decompression surgery in\npatients with sciatic endometriosis.\nDatabases to be searched: CENTRAL Cochrane Central Register of Controlled Trials),\nThe Cochrane Library CLIB, Embase.com, MEDLINE, PubMed, Scopus.\nUse a combination of controlled vocabulary (e.g., MeSH terms) and free-text terms in\nthe search strategy. The following keywords will be used: \"endometriosis\", \"sciatic\nnerve\", \"catamenial neuropathic pain\", \"sacral nerve\", \"sciatic pain\", \"sacral plexus\",\n\"neuropathic pain\", \"surgery\", \"laparoscopy\", \"decompression\", \"nerve\ndecompression\".\nCombine these terms using Boolean operators AND/OR) to ensure comprehensive\nretrieval of relevant literature. Develop and adapt equivalent search strategies for\neach database according to its specific indexing system and search syntax.\nScreening strategy\n10 Import all records identified through electronic database searches into a screening\nplatform, where duplicate entries will be automatically detected and removed. In\ncases of discordance or uncertainty during this automated process, a manual\nverification by a reviewer will be performed to ensure accurate duplicate removal.\nConduct title and abstract screening of unique records by two independent reviewers,\nbased on the predefined inclusion and exclusion criteria.\nRetrieve and assess full texts of potentially relevant studies in detail for eligibility.\nResolve any discrepancies in study selection through discussion and consensus. If\nconsensus cannot be reached, consult a third reviewer.\nprotocols.io | https://dx.doi.org/10.17504/protocols.io.bp2l6zn5dgqe/v1 July 21, 2025 6/11\n\nDocument the entire selection process using a PRISMA flow diagram, and record and\nreport reasons for exclusion at the full-text stage accordingly.\nData management\n11 Extract data using a standardized data extraction form developed specifically for this\nreview. Collect the following variables for each included study : \nmean age of patients, \nreported inclusion criteria, \ndiagnostic modalities used to confirm sciatic endometriosis, \nnumber of patients with sciatic nerve involvement and/or sacral plexus involvement, \ntype of surgery performed, \npreoperative and postoperative frequency of sciatic pain, \npreoperative and postoperative intensity of sciatic pain, \nlength of hospital stay, \npreoperative and postoperative quality of life, \nlength of postoperative follow-up, \nfrequency of major complications.\n12 If outcome data are missing, incomplete, or unclear, attempt to contact the\ncorresponding authors of included studies to request additional information or\nclarification. Perform this systematically for all studies lacking essential data required\nfor quantitative synthesis. If no response is received within two weeks after two\ncontact attempts, consider the data unavailable.\n13 If missing data concern the primary outcome (pre- and post-operative frequency of\nneuropathic sciatic pain), exclude the study from the review in accordance with\npredefined eligibility criteria. \n14 For secondary outcomes, exclude studies that do not report the relevant data from the\nspecific quantitative analysis concerned, but allow inclusion in other secondary\noutcome analyses if they provide extractable data for those endpoints. This ensures\neach analysis is based on complete and reliable data while maximizing inclusion of\nstudies across the overall synthesis.\nOutcomes\n15 Primary Outcome : \nChange in the frequency of neuropathic sciatic pain following laparoscopic nerve\ndecompression surgery in patients with endometriosis involving the sciatic nerve\nand/or sacral plexus. \nMeasure: Reported frequency of pain episodes (pre- and post-operative). \nMetric: Risk difference, odds ratio, or pooled proportion.\n15.1 Secondary Outcomes: \nprotocols.io | https://dx.doi.org/10.17504/protocols.io.bp2l6zn5dgqe/v1 July 21, 2025 7/11\n\n1 Intensity of neuropathic sciatic pain before and after surgery. \nMeasure: Visual Analog Scale, Numeric Rating Scale, or equivalent. \nMetric: Mean difference MD) or standardized mean difference SMD, where\navailable.\n2 Variation in the primary outcome by surgical technique. \nMeasure: Frequency and intensity of sciatic pain in surgical subgroups. \nMetric: MD or SMD within subgroups; p-value for interaction.\n3 Diagnostic tools used to identify sciatic endometriosis. \nMeasure: Frequency of use of each diagnostic modality. \nAnalysis: Descriptive synthesis and frequency tables.\n4 Diagnostic delay. \nMeasure: Time from symptom onset to confirmed diagnosis. \nMetric: Median or mean delay (in months or years), where available.\n5 Quality of life before and after surgery. \nMeasure: Validated quality-of-life instruments. \nMetric: Mean difference or descriptive synthesis depending on available data.\n6 Perioperative and postoperative complications. \nMeasure: Frequency of severe complications. \nMetric: Pooled complication rate (proportion), with subgroup analysis if applicable.\n7 Duration of postoperative follow-up. \nMeasure: Reported duration of follow-up. \nMetric: Median or mean duration (in months or years).\n8 Heterogeneity in clinical outcomes across studies. \nMeasure: I2 statistic and between-study variance (τ2). \nAnalysis: Used to guide interpretation and sensitivity analyses.\nStatistical Methods\n16 To synthesize outcomes across studies, a random-effects meta-analysis will be\nconducted to account for both clinical and methodological heterogeneity. All\nstatistical analyses will be performed using R software (notably the meta and metafor \npackages) and Jamovi.\n17 Estimate the between-study variance (τ2) using the restricted maximum likelihood\nREML) approach, in lin e with current recommendations from the Cochrane Statistical\nMethods Group. \nprotocols.io | https://dx.doi.org/10.17504/protocols.io.bp2l6zn5dgqe/v1 July 21, 2025 8/11\n\n18 Calculate confidence intervals for pooled effect estimates using the Hartung-Knapp-\nSidik-Jonkman HKSJ) method, which offers improved reliability in meta-analyses\ninvolving a small to moderate number of studies (≤ 20).\n19 For continuous outcomes (e.g., pain intensity scores), summarize effect sizes as\nmean differences MD) or standardized mean differences SMD, each reported with\ntheir 95% confidence intervals CIs. For dichotomous outcomes (e.g., recurrence or\ncomplications), express pooled effect estimates as risk ratios RR, risk differences\nRD, or pooled proportions, also with 95% CIs.\n20 When essential summary statistics (e.g., standard deviations) are not reported, derive\nthem from alternative data sources (e.g., p-values, confidence intervals, interquartile\nranges) using standardized imputation methods. If such calculations are not feasible\nor would compromise the reliability of the result, exclude the study from the\nquantitative synthesis for the outcome concerned, but allow it to contribute to the\nnarrative synthesis.\n21 Assess statistical heterogeneity using the I2 statistic and the between-study variance\n(τ2), complemented by Cochranʼs Q test and visual inspection of forest plots. When at\nleast 10 studies are included, calculate 95% prediction intervals to estimate the\nplausible range of true effects in future comparable populations.\n22 In the presence of substantial heterogeneity I2 > 50%, conduct sensitivity analyses\nto evaluate the robustness of the findings. Exclude studies judged at high risk of bias\n(as assessed using the JBI critical appraisal tools) and studies presenting significant\nmethodological or clinical differences.\n23 To explore potential sources of heterogeneity, perform subgroup analyses. Each study\nwill contribute to only one subgroup per analysis. \nPredefined subgroup comparisons include: \ntype of endometriotic involvement (sacral plexus vs. sciatic nerve); \nsurgical approach LANN technique vs. standard laparoscopy vs. robotic surgery); \nfollow-up duration 3c 6 months vs. ≥ 6 months).\n24 If meta-analysis is not feasible (due to excessive heterogeneity, missing data, or\nincompatible outcome measures), conduct a systematic synthesis. This qualitative\nsynthesis will aim to assess the direction, magnitude, and consistency of treatment\neffects across studies, while integrating both the clinical context and methodological\ncharacteristics of the included evidence.\nRisk of Bias and Quality Assessment\n25 Use the Joanna Briggs Institute JBI Critical Appraisal Tools to assess the\nmethodological quality of included studies, selected according to the specific study\nprotocols.io | https://dx.doi.org/10.17504/protocols.io.bp2l6zn5dgqe/v1 July 21, 2025 9/11\n\ndesign (e.g., case series, cohort studies, randomized controlled trials). \nTwo independent reviewers will perform the quality assessment. Resolve any\ndisagreements through discussion or, if necessary, adjudication by a third reviewer.\n26 Qualitatively assess risk of bias related to missing results, including potential publication\nbias and selective outcome reporting, based on the completeness of reporting and\nfeedback obtained from study authors. \nIf ten or more studies are included in the meta-analysis, consider funnel plots and/or\nEggerʼs test to evaluate the presence of small-study effects and publication bias.\nCertainty of Evidence\n27 Use the GRADE Grading of Recommendations Assessment, Development and\nEvaluation) approach to assess the certainty of evidence for each key outcome. \nThe following five domains will be considered: \nrisk of bias, \ninconsistency of results across studies,\nindirectness of the evidence,\nimprecision of the estimates,\npublication bias.\nBased on these criteria, rate the certainty of evidence as high, moderate, low, or very\nlow. The assessment will be performed independently by two reviewers, with\ndisagreements resolved through discussion or consultation with a third reviewer.\nSupport and Funding\n28 This review is supported by DRAW YOUR FIGHT, a nonprofit organization dedicated to\nraising awareness of invisible disabilities and chronic pain, and to promoting research\nthrough collaboration between patients and medical experts.\nThe review received no specific external funding.\nprotocols.io | https://dx.doi.org/10.17504/protocols.io.bp2l6zn5dgqe/v1 July 21, 2025 10/11\n\nProtocol references\n1 Howard FM. Endometriosis and mechanisms of pelvic pain. J Minim Invasive Gynecol. 2009 Sep-\nOct;16554050. doi: 10.1016/j.jmig.2009.06.017. PMID 19835795.\n2 Siquara De Sousa AC, Capek S, Amrami KK, Spinner RJ. Neural involvement in endometriosis: Review of\nanatomic distribution and mechanisms. Clin Anat. 2015 Nov;288102938. doi: 10.1002/ca.22617. Epub 2015\nSep 9. PMID 26296428.\n3 Coxon L, Wiech K, Vincent K. Is There a Neuropathic-Like Component to Endometriosis-Associated Pain?\nResults From a Large Cohort Questionnaire Study. Front Pain Res Lausanne). 2021 Nov 4;2743812. doi:\n10.3389/fpain.2021.743812. PMID 35295529; PMCID PMC8915551.\n4 Possover M. Laparoscopic morphological aspects and tentative explanation of the aetiopathogenesis of\nisolated endometriosis of the sciatic nerve: a review based on 267 patients. Facts Views Vis Obgyn. 2021\nDec;134369375. doi: 10.52054/FVVO.13.4.047. PMID 35026098; PMCID PMC9148715.\n5 Massimello F, Merlot B, Chanavaz-Lacheray I, Volodarsky-Parel A, Cela V, Kade S, Dennis T, Roman H. Robotic-\nassisted versus conventional laparoscopic management of deep endometriosis involving the sacral plexus and\nsciatic nerve: A comparative before and after study. Int J Gynaecol Obstet. 2024 Nov;1672839850. doi:\n10.1002/ijgo.15734. Epub 2024 Jun 22. PMID 38923519.\nAcknowledgements\nThis review is supported by DRAW YOUR FIGHT, a nonprofit organization dedicated to raising awareness of\ninvisible disabilities and chronic pain, and to promoting research through collaboration between patients and\nmedical experts.\nThe review received no specific external funding. \nprotocols.io | https://dx.doi.org/10.17504/protocols.io.bp2l6zn5dgqe/v1 July 21, 2025 11/11","source_license":"CC0","license_restricted":false}