REVIEW Laparoscopic uterosacral nerve ablation in chronic pelvic pain: an overview

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1 REVIEW Laparoscopic uterosacral nerve ablation in chronic pelvic pain: an overview Khalid S. Khan, 1 Sabina F. Khan, 2 Chika R. Nwosu, 2 Linga S. Dwarakanath 1 and Patrick F. W. Chien 2 1 Birmingham Minimal Access and Surgical Training (MAST) Centre, Academic Department of Obstetrics and Gynaecology, University of Birmingham, UK 2 Department of Obstetrics and Gynaecology, Ninewells Hospital and Medical School, Dundee, UK Keywords chronic pelvic pain, pelvic denervation, systematic review. Correspondence K. S. Khan, Academic Department of Obstetrics and Gynaecology, Birmingham Women's Health care NHS Trust, Birmingham B15 2TH, UK. Accepted for publication 20 January 1999 ABSTRACT Objective To assess the efficacy of laparoscopic uterine nerve ablation (LUNA) in the treatment of chronic pelvic pain, by means of a systematic overview of the published literature. Design Relevant papers were identified through electronic scanning of MEDLINE ( ), EMBASE (1980m 1997), the Science Citation Index and the Cochrane Library, and manual searching of the bibliography of known primary and review articles. Study selection, study quality assessment and data abstraction were performed independently in duplicate. For controlled studies data were used to generate odds ratios (OR) and their confidence intervals (CI). Subjects These were 555 women included in 11 case series and 250 women included in two controlled observational studies and three randomized trials. Main outcome measure Pain relief, measured in general terms or assessed using visual analogue or numeric pain scales. Results In the case of pelvic pain with no visible pathological findings at laparoscopy, randomized studies showed that LUNA had a trend towards better pain relief compared with no surgical intervention (OR 9.4, 95% CI 0.7 to 472; P ˆ 0.9) but its effect was inferior to presacral neurectomy (OR 0.24, 95% CI 0.07 to 0.8; P ˆ 0.01). Where there was endometriosis, controlled non-randomized studies showed that with ablative treatment of endometriosis, the outcomes were better with than without LUNA (OR 36.7, 95% CI 3.9 to 1625; P ˆ 0.001); however, presacral neurectomy did not show better results than LUNA (OR 0.30, 95% CI 0.03 to 1.76; P ˆ 0.1). One randomized controlled study in patients with endometriosis showed that LUNA plus ablative treatment was better than no intervention (OR 5.7, 95% CI 1.6 to 20.3; P ˆ 0.003), an effect that was not apparent in the subgroup with minimal endometriosis (P ˆ 0.24). Conclusion On theoretical grounds, LUNA has the promise of an efficacious intervention in alleviating pelvic pain. However, the pitfalls in the published research that we have identified and evaluated make it impossible for us to conclude that this intervention is universally effective. At best there is a trend indicating effectiveness in relieving primary dysmenorrhoea and mild to moderate endometriosis. For the majority of women with chronic pelvic pain, there is not sufficient evidence to guide therapeutic decision making with regard to laparoscopic uterine nerve ablation. q1999 Blackwell Science Ltd Gynaecological Endoscopy , 257±

2 258 K. S. KHAN et al. INTRODUCTION Chronic pelvic pain is a common cause of morbidity, crippling many women. 1,2 It is a frequent reason for referral to the gynaecology service with an estimated cost to the UK National Health Service of 158 million pounds each year. 3 The cause of the pain is often not obvious at diagnostic laparoscopy, and in the absence of pathological ndings, treatment is usually pragmatic without concrete indications. The surgical approach to the management of this problem is based on the interruption of pain pathways. The existence of nerve plexuses and ganglia in the uterosacral ligaments is described in the literature. 4,5 On theoretical grounds, division of these nerves should alleviate central pelvic pain. In his original work, Doyle 6,7 reported pain relief in 69/73 (95%) of women with primary dysmenorrhoea by means of transection of the uterosacral ligaments. Using the vaginal or abdominal approach, the attachments of these ligaments to the cervix were divided, which transected the uterine nerve trunks. The same tissue effect can be obtained laparoscopically by ablation of the uterosacral ligaments using laser or diathermy. The ability to perform this procedure with minimal access surgery has revived uterine nerve ablation as a possible treatment option for women with chronic pelvic pain. In the face of enthusiasm for laparoscopic uterine nerve ablation (LUNA), we were concerned that its clinical ef cacy may not have been assessed by methodologically sound research. Similar concern has been expressed by other authors, 1,2,8 but a comprehensive overview of the literature has not been reported so far. The current Cochrane Library review focuses only on primary dysmenorrhoea and it excludes nonrandomized studies. 9 Therefore, we decided to conduct a systematic review of all published articles on this intervention. METHODS Identi cation of the literature We conducted a comprehensive literature search to identify all the published observational and randomized studies evaluating the ef cacy of laparoscopic uterine nerve ablation. The databases searched included MEDLINE, EMBASE, the Science Citation Index and the Cochrane Library. A combination of key words `uterine nerve ablation' and `uterosacral nerve ablation' was used to identify the maximum number of relevant citations in MEDLINE (1966± 1997) and EMBASE (1980±1997). The Science Citation Index was searched prospectively to identify all the articles which cited Doyle's original work 6 on transection of the uterosacral ligaments. The Cochrane Controlled Trial Register was searched, and local experts on the laparoscopic treatment of chronic pelvic pain were contacted to identify any articles that might have been missed by our search strategy. Finally, the reference lists of all known primary and review articles were examined for additional relevant citations. After completing the electronic literature search, the citation lists (titles, medical subject headings and abstracts where available), were independently reviewed by two of the authors (S.F.K. and C.R.N.). The citations were categorized as relevant or not relevant, on the basis of whether or not the study evaluated laparoscopic uterine nerve ablation in women with pelvic pain. The complete manuscripts of the citations considered relevant by any of the observers were then reviewed in full. Any article ful lling the criteria listed below was considered eligible for inclusion in our overview. Study eligibility was independently assessed by two authors (K.S.K. and S.F.K.). Any disagreements regarding eligibility were resolved by consensus or arbitration by a third reviewer (L.S.D.). Selection criteria The following criteria were used to determine which studies were included in the overview. Population. This should consist of women undergoing laparoscopy for constant or intermittent, cyclic or acyclic pelvic pain, that had persisted for months and included dysmenorrhoea, deep dyspareunia or intermenstrual pain. 10 Intervention. This was laparoscopic uterine nerve ablation compared with either expectant management or with another intervention. Outcome. This was pain relief measured in general terms or assessed using visual analogue or numeric pain scales. Data extraction and assessment of study quality We extracted information from each article on the features of the study design, the characteristics of the population, the methods of carrying out the intervention and the assessment of outcomes. Data were extracted in duplicate (K.S.K. and S.F.K.) and abstracted data were examined independently by a Gynaecological Endoscopy , 257±265 q1999 Blackwell Science Ltd

3 LAPAROSCOPIC UTEROSACRAL NERVE ABLATION: AN OVERVIEW 259 third author (L.S.D.) to minimize errors. Any disagreements were resolved by consensus. We de ned methodological quality as an assessment of the extent to which the rigour of the study design and conduct avoided biases in the estimate of therapeutic ef cacy, thereby focusing on the internal validity of the study. The lowest quality evidence was provided by observational studies consisting of case series and case reports. 10,11 Controlled observational studies formed a higher level of evidence. Those with a retrospective design and historical controls were considered weaker than prospective studies with concurrent enrolment of controls and cases. Randomized trials provided the highest level of evidence as they were least subject to bias. 11,12 Randomized trials were subjected to further scrutiny of their quality, according to features of randomization, blinding and follow up. Trials having inadequacies in these aspects of study design provide an exaggerated estimate of treatment effect compared with those which do not. 13 Features of population and outcome also have an impact on the validity of observational studies. We therefore evaluated each study for these items. In observational studies, population enrolment was considered adequate if women in the series were consecutive patients. In randomized trials enrolment was considered adequate if the randomization sequence was generated properly and was concealed until the time of the intervention. 13 Outcome assessment was considered adequate if the women were kept blind to their group allocation, objective measures of pain were used, the duration of follow up was longer than 3 months, and the follow-up was >95% complete. Analysis Percentage agreement and the weighted kappa statistic were used for the analysis of agreement between the reviewers. Minimally acceptable agreement was set at a kappa level of 0.6. Analysis of the literature included in the overview was performed separately for chronic pelvic pain with and without positive pathological ndings. For case series the percentage of patients with pain relief was calculated. For controlled studies data were used to construct 2 2 tables from which odds ratios (OR) and their con dence intervals (CI) were calculated using the Epi Info software. 14 The OR represented the ratio of the odds of symptom relief in women with LUNA to the odds of symptom relief in the comparative group, i.e. OR > 1 indicated that LUNA provided better pain relief than the comparative intervention while OR < 1 indicated that women with LUNA were worse. In 2 2 tables with empty cells, one was added to all the cells for the calculation of the ORs and exact CIs. 15 In this circumstance, the 95% CIs are usually imprecise. We originally planned to combine studies to produce a pooled estimate of effect. However, the studies were so heterogeneous that it did not make methodological sense to combine them statistically. RESULTS Literature search The total number of citations identi ed initially was 88 (MEDLINE 34, EMBASE 22, Science Citation Index 27, Cochrane Library 5). Of these, 45 citations were considered relevant (MEDLINE 19, EMBASE 15, Science Citation Index 6, Cochrane database 5). There was reviewer agreement over relevance or irrelevance on 80/88 citations (91% agreement, kappa 0.81). The 45 citations considered relevant actually represented only 19 articles because many of the citations were repeated in the various databases that were searched. The full manuscripts of these articles were evaluated and nine studies were nally included in the overview. Reviewer agreement regarding inclusion or exclusion of these studies was 100% (kappa 1.0). An additional seven studies were identi ed through review of the bibliographies of known primary and review articles or through contact with experts. The main reason for exclusion was that laparoscopic uterine nerve ablation was not the intervention studied, or that the description of the intervention was unclear, especially in studies where laser laparoscopy was used for endometriosis. Methodological quality assessment The overview was therefore based on the 16 studies shown in the appendix and in Tables 1 and 2. Of these, 11 were case series, two were controlled observational studies (one retrospective and one prospective) and three were randomized trials. Three of the case series (A4, A7, A14) provided analyses of subgroups with and without visible disease. Generally, the case series (A1, A3±A9, A12, A14, A15) gave poor descriptions of the characteristics of their study design. Where reported, the enrolment of the women was not always consecutive, assessments of outcome were based on subjective q1999 Blackwell Science Ltd Gynaecological Endoscopy , 257±265

4 260 K. S. KHAN et al. or numeric scales, and follow up was often incomplete. Controlled observational studies (A11, A16) also suffered from de ciencies in outcome assessments. Among the randomized trials, one (A2) provided a poor description of the randomization procedure, and another (A10) used alternation which is not strictly randomization (quasi-randomization). Although the latter trial (A10) purported to be blind, it was not clear whether the number of abdominal incisions in the control and the experimental groups was the same. Only one trial (A13) ful lled several of the criteria for a high quality study, with a randomization sequence generated by computer and adequate blinding of women (including the use of a sham incision in the control group to ensure that the number of abdominal incisions was the same in all the women). Laparoscopic uterine nerve ablation in pelvic pain without visible pathological appearances Our search identi ed four observational case series and two randomized trials in women with menstrual pain and no visible disease at diagnostic laparoscopy. The four case series provided evidence of symptom relief in 36±91% patients at 6±12 months follow up (Table 1). In the quasi-randomized trial (A10) 5/11 (45%) of the women reported signi cant relief from menstrual pain 12 months after laparoscopic uterine nerve ablation compared with 0/10 in the control group (OR 9.4, 95% CI 0.7 to 472, P ˆ 0.09). In another randomized trial (A2) laparoscopic uterine nerve ablation was compared with presacral neurectomy. At 12 months 27/33 (82%) of women undergoing presacral neurectomy showed more than 50% pain relief compared with 18/35 (51%) of women treated by uterine ablation (OR 0.24, 95% CI 0.07 to 0.08; P ˆ 0.01). Although presacral neurectomy seems to be better than laparoscopic uterine nerve ablation, it was associated with constipation in 94% of the women in this trial. Laparoscopic uterine nerve ablation in pelvic pain associated with endometriosis Our search identi ed seven case series, two observational comparative studies and one randomized trial in women with endometriosis, where the symptoms included dysmenorrhoea, pelvic pain not related to menstruation and dyspareunia. Some of the case series also included women without any disease. Laparoscopic uterine nerve ablation was bene cial in 72±93% of the women when assessed 12±18 months after their operation (Table 2). The controlled observational studies included one study (A11) comparing laparoscopic uterine nerve ablation plus ablation of the endometriosis with ablation of the endometriosis alone. Laparoscopic ablation of uterine nerve and endometriosis gave better results than ablation of endometriosis alone (relief of non-menstrual pain at 18 months follow up: OR 36.7, 95% CI 3.9 to 1625; P ˆ 0.001) (Table 2). The other controlled study (A16) was retrospective in design, and it compared laparoscopic uterine nerve ablation with laparoscopic presacral neurectomy in women having laparoscopic treatment for endometriosis; there was no difference between the two methods of pelvic denervation (OR for relief of menstrual pain at 6 months after treatment 0.30, 95% CI 0.04 to 1.76; P ˆ 0.1). The randomized trial in women with endometriosis (A13) showed resolution or improvement of symptoms in 20/32 (62%) women at 6 months after laparoscopic ablation of endometriosis plus uterine nerve ablation; in the control group only 7/31 (23%) showed improvement (OR 5.7, 95% CI 1.5 to 343; P ˆ 0.003). Although the overall differences in the two groups were statistically signi cant, the subgroup of women with minimal endometriosis did not show any bene t with treatment (6/13 vs. 4/16, P ˆ 0.24). DISCUSSION In this overview of the role of laparoscopic uterine nerve ablation in the management of chronic pelvic pain, an attempt was made to ful l the criteria for a rigorous systematic review article. 16 A clear research question was posed; the literature search, data abstraction and quality assessments were performed in duplicate, and quantitative summary of the evidence was produced where possible. Hence, the inferences are likely to be more valid than those of traditional and qualitative reviews which are notorious for combining opinion with evidence. From this overview, laparoscopic uterine nerve ablation seems to be an ef cacious intervention in dysmenorrhoea without pelvic disease, and in endometriosis when it is used along with ablation of mild to moderate endometriosis. The quality of the literature on which our inferences were based was relatively poor. In particular, there was a lack of high quality randomized evidence. There was no lack of observational case series, and we have summarized all such reports that we identi ed from our search. However, observational studies without control arms Gynaecological Endoscopy , 257±265 q1999 Blackwell Science Ltd

5 LAPAROSCOPIC UTEROSACRAL NERVE ABLATION: AN OVERVIEW 261 LUNA in pelvic pain without pathology LUNA vs. laparoscopy alone Lichten et al ( ) LUNA vs. LSPN Chen et al ( ) LUNA in pelvic pain with endometriosis LUNA + ablation vs. laparoscopy alone Sutton et al ( ) LUNA + ablation vs. ablation alone Ostrzenski et al ( ) LUNA + ablation vs. LPSN + ablation Zullo et al ( ) 0.01 LUNA worse 0.1 LUNA better 1 10 Odds ratio Figure 1 Effectiveness of laparoscopic uterine nerve ablation (LUNA) in women without visible pathological ndings and in those with endometriosis.the diagram represents odds ratios for symptom relief, with 95% con dence intervals, based on data taken from comparative studies in Tables 1 and 2, using outcomes for the longest follow up of 3±12 months. Dysmenorrhea was used as the outcome measure when several outcomes were reported. Statistical analysis was carried out using Epi Info software version The estimates of effect should be interpreted with caution, as the quality of the primary studies was generally poor (only Lichten et al. (A10) Chen et al. (A2) and Sutton et al. (A13) reported randomized studies; the others were observational), and LUNA was often carried out with other cointerventions (see Tables 1 and 2 for details). LPSN, laparoscopic presacral neurectomy. provide the lowest level of evidence, as we highlighted in the description of quality assessment. One might then question our wisdom in including this literature in our overview. We reviewed identi ed case series because in health technology assessment of minimal access surgery there has to be an initial evaluation of the safety and stability of new interventions. One view is that randomized trials should not be entertained until the evaluative phase has been completed. 17 The case series, in our view, provide this evaluative evidence for laparoscopic performance of uterine nerve ablation with laser or diathermy. However, this evidence alone is not suf cient to assess the clinical effectiveness of uterine nerve ablation for which randomized trials remain the gold standard. We considered the evaluation of outcomes to be an important factor in avoiding biases in the assessment of therapeutic ef cacy. Ideally, there should be doubleblinding 11,13 but this is not possible in studies of surgical interventions such as laparoscopic uterine nerve ablation. However, maintenance of singleblinding is essential because patients' awareness of their group allocation can modify their responses. In the measurement of pain we regarded objective measures as better than subjective assessments. In scaled measures of pain, patients nd it dif cult to choose between two adjacent categories of pain as interpretation of differences between categories is unclear. 16 Because of this problem, visual analogue scales for measurement of pain were considered superior to other methods of evaluation of pain. 18 The duration of follow up was considered adequate by us only if assessments were made after 3 months or more. This is because the placebo effect can be expected to last for up to 3 months in patients with pelvic pain. 19,20 The lack of these features in many of the studies has an impact on the strength of our conclusions. Our inferences regarding the clinical effectiveness of uterine nerve ablation in dysmenorrhoea with no visible pathological appearances were based mainly on two randomized trials (Table 1, Fig. 1). This evidence showed that uterine nerve ablation provided better pain relief compared with no surgical intervention, but this result was not statistically signi cant. Conversely, uterine nerve ablation was inferior when compared to presacral neurectomy. However, presacral neurectomy was associated with a signi cant adverse effect on bowel function, resulting in constipation. In addition, presacral neurectomy is a more extensive surgical intervention, and the Royal College of Obstetricians and Gynaecologists classi es it as a level 4 procedure requiring advanced skills. 21 Hence, presacral neurectomy cannot be recommend for widespread use. Laparoscopic uterine nerve ablation, on the other hand, is a simple procedure and does not require a subspecialist. 21 If it is shown to be effective in future research, its wider application in the management of women with pelvic pain would be practicable. q1999 Blackwell Science Ltd Gynaecological Endoscopy , 257±265

6 262 K. S. KHAN et al. Table 1 Laparoscopic uterine nerve ablation in chronic pelvic pain without visible pathology Follow up Population a Duration, Completeness, Published study Enrolment n Study design Nerve ablation modality Method of pain measurement months % Symptom relief (%) b,c Observational studies Feste et al [A5] Consecutive 10 Case series CO2 laser Not described 12 >95 7/10 (70) d Sutton,1989 [A14] Not described 26 Case series CO2 laser Visual analogue scale ± 84 16/22 (73) Daniell 1989 [A4] Not described 20 Case series KTP laser Not described 6 >95 12/20 (60) d Donnez et al [A5] Not described 100 e Case series CO2 laser Not described >12 >95 91/100 (91) d Gurgan et al [A8] Not described 23 Case series CO2 laser Verbal multidimensional score /20 (70) d /14 (36) Wiborny et al [A15] Not described 16 Case series Diathermy + scissors Not described /14 (86) /12 (83) /11 (82) Experimental studies Lichten et al [A10] Odd/even allocated to LUNA Diathermy + scissors 5-point rating system 3 >95 9/11 (82) vs. 0/10 (0) d alternation 10 to no surgical treatment (patients blind to intervention) 12 >95 5/11 (45) vs. 0/10 (0) Chen et al [A2] Randomization, allocated to LUNA Diathermy 5-point rating system 3 >95 29/35 (83) vs. 29/33 (88) f unclearly described 33 allocated to LPSN 12 >95 18/35 (51) vs. 27/33 (82) LUNA, laparoscopic uterine nerve ablation; LPSN, laparoscopic presacral neurectomy. a Patients with dysmenorrhoea were enrolled in all the studies. b In the absence of original gures, outcome data computed from percentages reported in the original papers. c Comparisons shown as LUNA vs. other group. d Criteria for symptom relief not described. e Unclear whether only patients without pathology were included. f Symptom relief de ned as pain relief of 50±100%. Table 2 Laparoscopic uterine nerve ablation in chronic pelvic pain associated with endometriosis Follow up Population a Duration, Completeness, Published study Enrolment n Study design Nerve ablation modality Method of pain measurement months % Symptom relief (%) b,c Observational studies Carter et al [A1] Consecutive 56 Case series of laparoscopic Nd: YAG laser 1±10 pain scale Outcome data not reported separately for LUNA (73% with endometriosis) treatment including LUNA Sutton1989 [A14] Not described 100 Case series CO2 laser Visual analogue scale ± 94 81/94 (86) Daniell 1989 [A4] Not described 80 Case series of LUNA KTP laser Not described 6 >95 60/80 (75) d Gynaecological Endoscopy , 257±265 q1999 Blackwell Science Ltd

7 LAPAROSCOPIC UTEROSACRAL NERVE ABLATION: AN OVERVIEW 263 Corson et al [A3] Not described 12 Case series of LUNA Nd: YAG laser Numerical scale >4 58 6/7 (86) d + adhesiolysis + ablation of endometriosis Feste et al [A7] Consecutive 32 Case series of LUNA CO2 laser Not described 12 >95 23/32 (72) d + ablation of endometriosis Kojima et al [A9] Consecutive 14 Case series of LUNA Nd: YAG laser Not described Not >95 13/14 (93) d + adhesiolysis reported + ablation of endometriosis Ewen et al [A6] Not described 14 Case series of LUNA CO2/KTP laser Not described 6±18 >95 13/14 (93) d (43% with endometriosis) + ablation of endometriosis (+ TCRE) Papasakelatiou,1995 [A12] Consecutive 52 Case series of LUNA CO2 laser Pain relief scale 0± /43 (72) e (79% with endometriosis) + additional treatment for /43 (58) any pelvic pathology /43 (51) /43 (40) Controlled observational studies Ostrzenski et al [A11] Patients' choice allocated to LUNA CO2 laser Not described 18 >95 20/20 (100) vs. 7/20 (35) b + ablation of endometriosis (subjective assessment) (dysmenorrhoea) + ventrosuspension 20/20 (100) vs. 1/20 (5) (dyspareunia) 20 allocated to 20/20 (100) vs. 12/20 (60) ablation of endometriosis Zullo et al [A16] Retrospective cases with LUNA Bipolar diathermy 1±10 numeric linear 6 >95 25/33 (76) vs. 21/23 (91) f Case-control + ablation/excision of Scissors transection pain scale (dysmenorrhoea) endometriosis 11/14 (76) vs. 14/14 (100) + adhesiolysis (dyspareunia) 17/34 (50) vs. 14/16 (87) 24 cases with LPSN (non-menstrual pain) + ablation/excision of endometriosis + adhesiolysis Experimental study Sutton et al [A13] Randomization allocated to LUNA CO2/KTP laser Visual analogue scale /32 (56) vs. 15/31 (48) b Computerized + ablation of endometriosis + subjective assessment /32 (62) vs. 7/31 (23) sequence generation (patients blind to intervention) 31 allocated to no surgical treatment LUNA, laparoscopic uterine nerve ablation; LPSN, laparoscopic presacral neurectomy; KTP, Potassium-titanyl-phosphate; TCRE, transcervical resection of endometrium. a Patient symptomatology included dysmenorrhoea, nonmenstrual pelvic pain and dyspareunia. b In the absence of original gures outcome data computed from percentages reported in the original papers. c Comparisons shown as LUNA vs. other group. d Criteria for symptom relief not described. e Symptom relief de ned as pain cured or improved based on subjective assessment. Symptom relief de ned as pain relief of 2 points or more. f q1999 Blackwell Science Ltd Gynaecological Endoscopy , 257±265

8 264 K. S. KHAN et al. In endometriosis, our conclusions on the clinical effectiveness of uterine nerve ablation were based on two controlled non-randomized studies and one randomized trial (Table 2, Fig. 1). The non-randomized studies showed that ablative or excisional treatment for endometriosis when accompanied by pelvic denervation showed improved outcomes, but presacral neurectomy did not prove any more effective than uterine nerve ablation. The only randomized controlled study in endometriosis supported the role of uterine nerve ablation along with ablative or excisional treatment compared with no surgical intervention. Although this study was rigorous, it was not designed to address the following issues: in minimal endometriosis, it did not show a bene t (a result that may represent a type II error arising from small sample size), and in mild to moderate endometriosis, it could not distinguish whether the bene t arose from the transection of the uterosacral ligaments or from the ablation of the endometriotic lesions. A provisional report of a subsequent unpublished study to clarify the latter issue did not demonstrate any bene cial effect from the use of uterine nerve ablation. 22 In summary, the promise of this simple procedure, based on division of nerves known to be anatomically located in the uterosacral ligaments, is not ful lled by the evidence produced by its proponents so far. The pitfalls in the published research that we identi ed and evaluated make it impossible for us to conclude that this intervention is universally effective. At best there is a trend that it is effective in primary dysmenorrhoea and mild to moderate endometriosis. For the majority of women with chronic pelvic pain, there is not suf cient evidence to guide therapeutic decision making with regard to laparoscopic uterine nerve ablation. Therefore, there is a need for a rigorous randomized controlled trial to establish the ef cacy of laparoscopic uterosacral nerve ablation in women with chronic pelvic pain. Such a trial has been designed to address the outcomes of this intervention with respect to pain, sexual function and quality of life. This multicentre study has commenced recruitment and is being coordinated from the Birmingham Clinical Trials Unit, UK. 23 No doubt, in due course, we will report the results of the completed study. REFERENCES 1 Howard FM. The role of laparoscopy in chronic pelvic pain: promise and pitfalls. Obstetric and Gynecological Surveys 1993; 48: 357±87. 2 Stones RW. Chronic Pelvic Pain. 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9 LAPAROSCOPIC UTEROSACRAL NERVE ABLATION: AN OVERVIEW Fedele L, Marchini M, Acaia B, Gara ola U, Tiengo M. Dynamics and signi cance of placebo response in primary dysmenorrhoea. Pain 1990; 36: 43±7. 20 Baker PN, Symonds EM. The resolution of chronic pelvic pain after normal laparoscopy ndings. American Journal of Obstetrics and Gynecology 1992; 166: 835±6. 21 Royal College of Obstetricians and Gynaecologists Working Party. Report of the RCOG Working Party on Training in Gynaecological Endoscopic Surgery. London: RCOG Press, Dover RW, Pooley A, Haines P, Sutton CJG. A prospective randomised double-blind trial of laparoscopic laser uterine nerve ablation in the treatment of pelvic pain associated with endometriosis: a provisional report. British Journal of Obstetrics and Gynaecology 1998; 105 (Suppl. 17): Birmingham Clinical Trials Unit. The Luna Trial. URL: APPENDIX: STUDIES INCLUDED IN THE OVERVIEW OF LAPAROSCOPIC UTERINE NERVE ABLATION IN CHRONIC PELVIC PAIN A1 A2 A3 Cater JE. Laparoscopic treatment of chronic pelvic pain in 100 adult women. Journal of the American Association of Gynecologic Laparoscopists 1995; 2: 255±62. Chen F-P, Chang S-D, Chu K-K, Soong Y-K. Comparison of laparoscopic presacral neurectomy and laparoscopic uterine nerve ablation for primary dysmenorrhoea. Journal of Reproductive Medicine 1996; 41: 463±6. Corson SL, Unger M, Kwa D, Batzer FR, Gocial B. Laparoscopic laser treatment of endometriosis with Nd:YAG sapphire probe. American Journal of Obstetrics and Gynecology 1989; 160: 718±23. A4 Daniell JF. Fiberoptic laser laparoscopy. BaillieÁre's Clinical Obstetrics and Gynecology 1989; 3: 545±62. A5 Donnez J, Nisolle E. CO 2 laser laparoscopic surgery. BaillieÁre's Clinical Obstetrics and Gynecology 1989; 3: 525±43. A6 Ewen SP, Sutton CJG. A combined approach for painful heavy periods: laparoscopic laser uterine nerve ablation and endometrial resection. Gynaecological Endoscopy 1994; 3: 167±8. A7 Feste JR. Laser laparoscopy: a new modality. Journal of Reproductive Medicine 1985; 30: 413±17. A8 Gurgan T, Develioglu O, Bulent U, Hulusi Z, Aksu T, Kisnisci HA. Laparoscopic CO 2 laser uterine nerve ablation for treatment of drug resistant primary dysmenorrhoea. Fertility and Sterility 1992; 58: 422±4. A9 Kojima E, Morita M, Otaka K, Yano Y. Nd:YAG laser laparoscopy for ovarian endometriomas. Journal of Reproductive Medicine 1990; 35: 592±6. A10 Lichten EM, Bombard J. Surgical treatment of primary dysmenorrhoea with laparoscopic uterine nerve ablation. Journal of Reproductive Medicine 1987; 32: 37±41. A11 Ostrzenski A. A new translaparoscopic approach in endometriosis. Materia Medica Polona 1991; 23: 168±71. A12 Papasakelariou C. Long-term results of laparoscopic uterosacral nerve ablation. Gynaecological Endoscopy 1996; 5: 177±9. A13 Sutton CJG, Ewen SP, Whitelaw N, Haines P. Prospective, randomized, double blind controlled trial of laser laparoscopy in the treatment of pelvic pain associated with minimal, mild, and moderate endometriosis. Fertility and Sterility 1994; 62: 696±700. A14 Sutton CJG. Laser uterine nerve ablation. In: Donnez J, ed. An Atlas of Laser Operative Laparoscopy and Hysteroscopy. Leuven: Nauwelaerts 1989: 43±52. A15 Wiborny R, Pichler B. Endoscopic dissection of the uterosacral ligaments for the treatment of chronic pelvic pain. Gynaecological Endoscopy 1998; 7: 33±5. A16 Zullo F, Pellicano M, DeStefano R, et al. Ef cacy of laparoscopic pelvic denervation in central-type chronic pelvic pain: a multicenter study. Journal of Gynecological Surgery 1996; 12: 35±40. q1999 Blackwell Science Ltd Gynaecological Endoscopy , 257±265

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