{"paper_id":"24ddfa80-128e-46ec-a53f-81b205848a79","body_text":"*Corresponding author email: mette.moen@ntnu.no\nSymbiosis Group\nSymbiosis www.symbiosisonline.org \nwww.symbiosisonlinepublishing.com\nEndometriosis does not Increase Risk of Surgical \nComplications. A Comparative Study \nSolveig Skrede1,Torbjorg Standal Skaravik1 and Mette Haase Moen1,2*\n1Department of Laboratory Medicine, Children’s and Women’s Health, Faculty of Medicine, Norwegian University of Science and Technology, NO-7491 \nTrondheim, Norway\n2Department of Obstetrics and Gynecology, Trondheim University Hospital [St Olav’s Hospital], Olav Kyrres gate 17, NO-7006 Trondheim, Norway\nSOJ Surgery Open AccessResearch Article\nIntroduction\nEndometriosis is a chronic disease, prevalent in 6-10% of \nwomen of reproductive age [1], where endometrial-like tissue \nis placed outside the uterus causing an inflammatory reaction. \nThere is little correlation between the extent of the disease \nand the symptoms. Affected women may experience symptoms \nlike pelvic pain, infertility and dyspareunia, but can also be \nasymptomatic [2]. Other symptoms are dysmenorrhoea, dysuria, \npain at defecation, fatigue and nausea [2]. Laparoscopy is the \ngold standard for diagnosing endometriosis [2]. Endometriosis \ncan be treated surgically or medically. The goal of the treatment \nis pain relief and improving fertility. The choice of treatment is \nindividualized with respect to age, symptoms and family planning. \nSurgical treatment is preferably performed in connection with \nthe diagnostic procedure. Repeated surgery is common [3], often \nalternated with hormonal treatment. Previous investigations \nconcerning the results of surgery have focused on certain \nmanifestations such as ovarian, peritoneal or deep infiltrating \nendometriosis, laparoscopic operations or results obtained by a \nsingle surgeon [4-7]. \nSurgical treatment includes removal of endometriotic \ndeposits with excision or ablation and removal of adhesions. A \nCochrane review [8] concludes that laparoscopic treatment has a \nsignificantly better outcome on symptoms than mere diagnostic \nlaparoscopy but  there is no current agreement on what surgical \ntreatment is preferable concerning endometriosis associated \nwith pelvic pain. \nSurgery implies a risk of complications. Surgery for \nendometriosis could entail a higher risk because of adhesions \nto the bowel and the urinary tract caused by the nature of \nthe disease, or due to repeated surgery. In recent years The \nNorwegian System of Compensation to Patients has received a \nconsiderable number of claims concerning complications after \noperations for endometriosis [9]. However, it is unknown if this \nreflects a higher rate of operations on this indication or a real \nincreased risk of surgical complications. \nThe purpose of this study was to investigate if surgery for \nendometriosis entails a higher complication rate compared to the \nsame surgical procedure performed on other benign indications.  \nMethods\nThis is a retrospective case review based on operations \ncarried out from January 2000 to December 2008 at The \nDepartment of Obstetrics and Gynecology, St. Olavs Hospital, \nTrondheim, Norway, a university hospital with secondary and \ntertiary service. A total of 200 patients were discharged with the \nICD-10 diagnosis endometriosis, N80.1-N80.9. The patients were \ndivided into three groups according to the type of surgery: partial \nor complete adnexal surgery, uterine surgery with or without \nAbstract\nEndometriosis surgery is considered often to be complicated \noperations. We therefore wanted to study the rate of complications in \nsurgery for endometriosis compared to similar surgical intervention \non other indications.  The study was performed as a retrospective \ncase-control study in a university hospital with secondary and \ntertiary medical service. 200 women with endometriosis having been \noperated between 2000 and 2008 were matched with 400 controls \nhaving similar operations on other benign indications in the same \nperiod of time and being operated by the same staff in the hospital. \nWomen identified with the ICD-10 diagnosis of endometriosis were \nfound in the database at the gynecological department and matched \nwith similar operative procedures performed on patients without \nendometriosis. Demographic data, surgical methods and surgical \ncomplications within 60 days were registered. Main outcome were \nrate of per- and postoperative complications. \nRepeated surgeries, adhesiolysis, a longer operation time, bleeding \nand wound infection were significantly more common in endometriosis \nsurgery than in controls. However, there was no significant difference \nin rate of severe and total complications between the endometriosis \nand the control group (8.0% versus 6.3% and 28.0% versus 25.8%). \nThe study indicates that there in our department is no greater risk \nof complications in operations performed for endometriosis than for \nsimilar operations for other benign diseases.\nKeywords: Endometriosis; Laparoscopy; Laparotomy; Surgical \ncomplications. \nReceived: August 05, 2014; Accepted: November 03, 2014; Published: November 14, 2014\n*Corresponding author: Mette Haase Moen, Professor, Department of  Obstetrics  and Gynecology, Trondheim University Hospital, St Olav’s Hospital, \nOlav Kyrres gate 17, NO-7006 Trondheim, Norway, Tel: +47-93-454687; Fax: +47-72-573801, E-mail address: mette.moen@ntnu.no\n\nPage 2 of 4Citation: Skrede S, Skaravik TS, Moen MH (2014) Endometriosis does not Increase Risk of Surgical Complications. A Comparative \nStudy. SOJ Surgery 1(2), 4.\nEndometriosis does not Increase Risk of Surgical Complications a Comparative Study\n Copyright: \n© 2014 Moen et al.\nadnexal surgery, and peritoneal surgery only. Patients with \nadenomyosis or malignancy were excluded. The revised ASRM \nclassification was used to determine the stage of endometriosis \n[10]. The control group consisted of 400 patients, two controls \nfor each case. These patients had undergone surgery in the same \ndepartment during the same period of time. Using the  NCMP/\nNCSP Classification of Surgical Procedures [11], we matched \npatients with controls having had similar type of surgery. The \nendometriosis patients with peritoneal surgery were matched \nwith controls undergoing tubal sterilization as we found this to be \nthe most comparable intervention, as women in both groups had \nlaparoscopic cauterization. All patients had undergone surgery \ndue to a benign indication by the same staff of gynecologists, \nirrespective of the diagnosis. In our department the routine is \nthat trainees are assisted by specialists. \nDemography, stage of endometriosis, type of surgery, and per- \nand postoperative complications within 60 days were registered \nfrom medical records. Severe complications comprised injury to \nthe urinary tract or intestines and life threatening peroperative \nepisodes. Information about hospital stay and sick leave was \nobtained.\nStatistical analyses were carried out using the SPSS software \npackage, version 16.0. Data were compared using: The Chi-\nsquare test at cross tabulations, The Independent-Samples T-test \nfor finding means and The Mann-Whitney U-test to compare \ntwo independent groups. We considered p-values < 0.05 as \nstatistically significant. The sample size of 200 cases and 400 \ncontrols was based on power computation calculated by the \nsoftware “SamplePower”. As the expected surgical procedures \ndiffered in type, we arbitrarily estimated the intra- and \npostoperative complication rate in the control group to be 5% \nand in the cases of endometriosis to be 12%. We would then be \nable to show a statistical significant difference with a power of \n83%.\nThe study was approved by the Regional Research Ethics \nCommittee of Central Norway, Norwegian Social Science Data \nServices and Privacy Ombudsman for Research.\nResults\nPatients with endometriosis were significantly younger \nthan controls group (38.1 years ± 8.4 versus 46.2 years ± 15.6, \np < 0.001). Previous surgery was more common among women \nwith endometriosis (Table 1) .  Table 2 shows the stage of \nendometriosis according to the ASRM classification [10].\n A total \nof 85.5% had moderate or severe endometriosis. Table 3 shows \nthat 58.5% of the patients had open surgery, while 41.5% had \nlaparoscopic operations only. The equal frequencies refer to \nmatching. However, it should be mentioned that some patients in \neach laparotomy group had had a conversion from laparoscopy \n(9.5% with endometriosis versus 7.5% of controls, n.s.). In Table \n4 is seen a significant difference between the endometriosis group \nand controls concerning operation time (106 min. ~94 min, p = \n0.008), need of adhesiolysis (54.5%∼29.5%, p = 0.000) and blood \nloss (366ml∼274ml, p = 0.001 ). However, neither the length of \nhospital stay after surgery nor the length of sick leave differed \nbetween the two groups. Table 5 shows no significant difference \nin the rate of severe and total complications between the two \ngroups (8.0% versus 6.3% and 28.0% versus 25.8%). Wound \ninfection was the only complication that occurred significantly \nmore often in the endometriosis group (5.5%~2.2%, p = 0.04) but \nthe frequency was low. \nDiscussions\nThe main findings of our study were that endometriosis \npatients were younger and more often had previous surgery. \nAdhesiolysis, longer operation time, greater blood loss and \nwound infections were more common in endometriosis surgery. \nHowever, the rate of severe or moderate complications did \nnot differ significantly from similar surgery for other benign \nconditions.\nThe strength of our study is that the patients and the controls \nwere operated in the same department by the same staff and \nin the same interval of time. We were able to trace all medical \nrecords from the period of investigation. The weakness is the \nretrospective design investigating surgery performed during \nseveral years with different surgeons. However, as this is a \ncomparative study with the controls recruited in the same period, \nthis effect should be eliminated by matching.\nThe rate of laparotomy (58.5%) was higher than expected, \nbut it should be noted that 9.5% in the endometriosis group and \n7.5% among the controls were conversions from laparoscopy. \nToday the use of laparoscopic surgery probably is higher. Patients \nwith deep infiltrating endometriosis of the rectovaginal space \nwere not present in our material as these patients routinely are \nreferred to a national specialist center for surgery, and in addition \nthey could not have been matched with controls.\nVariable\nEndome-\ntriosis\n(n = 200)\nControl\n(n = 400) p-value\nAge, years (mean ± SD) 38.1 ± 8.4 46.2 ± 15.6 0.00\nPrevious surgery, n (%)\nNo 111(55.5) 260(65) <0.05\nYes 89(44.5) 140(35) <0.05\n1 previous operation 50 (25) 96 (26) <0.05\n≥ 2 previous operations 39 (19.5) 44(11.1) <0.05\nNumber of previous surgery, \nmean ± SD 0.78 ± 1.15 0.56 ± 1.13 0.026\nTable 1: Characteristics of the 200 patients operated for endometriosis \nand 400 controls concerning age and previous surgery.\nStage of endometriosis (n = 200)\nI Minimal, n (%) 3 (1.5)\nII Mild, n (%) 26 (13)\nIII Moderate, n (%) 97 (48.5)\nIV Severe, n (%) 74 (37) \nTable 2: Stage of endometriosis in 200 patients according to the ASRM \nclassification (Revised American Society for Reproductive Medicine \nclassification of endometriosis) [10].\n\nPage 3 of 4Citation: Skrede S, Skaravik TS, Moen MH (2014) Endometriosis does not Increase Risk of Surgical Complications. A Comparative \nStudy. SOJ Surgery 1(2), 4.\nEndometriosis does not Increase Risk of Surgical Complications a Comparative Study\n Copyright: \n© 2014 Moen et al.\nAs endometriosis is a disease mainly affecting women in \nreproductive age, it is obvious that the patients had a lower mean \nage than controls, with 38 years versus 46 years. This was also \ndemonstrated in the study of Maytham et al. [6] in operations \nfor colorectal endometriosis, which showed a much greater \ndifference with a median age of 33 years in the endometriosis \ngroup and 72 years in the control group. However, the lower \nage of patients compared to controls in our material probably \nwould not influence the result because both groups were mostly \npremenopausal women.  \nIn spite of the endometriosis group being eight years \nyounger, they have had significantly more previous gynecological \noperations. This is in accordance with a high recurrence rate \nof endometriosis in fertile women [3]. It also confirms that \nendometriosis is a chronic recurrent disease. \nMost patients in our study group (85.5%) had moderate \nor severe endometriosis. This, in addition to a higher rate of \nprevious surgery, explains the high rate of adhesiolysis. Pelvics \nsurgery in an area with adhesions is more risky. This might \nexplain a prolonged operation time of 12 minutes in the study \ngroup as well as a significantly increased blood loss. Blood \ntransfusion was, however, not more common among patients \nwith endometriosis. A transfusion rate of 3.0% is comparable to \nthe rate in the study of Spilsbury et al.\n [12] where 2.41% of the \npatients required blood transfusions. \nOverall we found that 28.0% of the patients with \nendometriosis had at least one complication, versus 25.8% in the \ncontrol group. Because of the lack of similar studies and because \nthere is no standard definition of complications, we cannot \ncompare the overall result with other studies.\nThe total rate of severe complications, including urological \nand intestinal injury, was 12% versus 8.3%. It is stated that \nadhesions, previous surgery and endometriosis may increase the \nrisk of bladder injury [13,14]. However, our data do not support \nthis, since there was no significant difference between the two \ngroups. Urinary tract injuries occurred equally in the two groups \nand the frequencies of 1,5% were comparable to the figures \nof 1,1%  in a recent study of Rettenmaier et al.\n [14] . Intestinal \ninjury occurred in 6.5% of the patients with endometriosis and \nin 5.5% of the control patients. This is a higher percentage than \nfound in the study of Rettenmaier et al. [14]. The explanation for \nthis may be that we classified minor damage to the serosa as an \nintestinal injury. There was no significant difference between \nthe two groups in the rate of reoperations done within 60 days \nafter surgery, with four (2.0%) patients in the endometriosis \ngroup and ten (2.5%) patients in the control group. Three of the \nreoperations in the endometriosis group were caused by bowel \ninjury and one by ureter injury. In the control group, bowel injury \ncaused three of the reoperations and bladder injury caused one. \nTwo were caused by hematomas and four by minor complications. \nWound infection occurred in 5.5% of the patients with \nendometriosis and in 2.2% of the control group. This constitutes \na significant difference, but the reason for this is unclear and \ndifficult to account for. It may be caused by longer surgery time \nVariable Endometriosis\n(n = 200)\nControl\n(n = 400)\nAdnex only, n (%) 126 (63) 252 (63)\nHysterectomy with or without ad -\nnexal surgery, n (%) 62 (31) 124 (31)\nRemoval of peritoneal implants/\nsterilization, n (%) 13 (6.5) 26 (6.5)\nLaparoscopy, n (%) 83 (41.5) 166 (41.5)\nLaparotomy, n (%) 117 (58.5) 234 (58.5)\nTable 3:  Distribution of 200 patients with endometriosis and 400 \nmatched controls between different procedures and surgical techniques.\nVariable\nEndome-\ntriosis\n(n = 200)\nControl\n(n = 400) p-value\nSurgery time, min. (mean ± \nSD)* 106.2 ± 54.9 94.2 ± 48.3 0.008\nAdhesiolysis, n (%) 109 (54.5) 111 (29.5) 0.000\nBlood loss, ml. (mean ± SD)** 366 ± 431 274 ± 470 0.040\nLength of hospital stay, days \n(mean±SD) 3.4 ± 2.9 3.3 ± 2.4 0.446\nSick leave, days (mean ± \nSD)*** 26.3 ± 20.4 27.0 ± 15.0 0.702\nTable 4:  Surgical parameters, hospital stay and sick leave for 200 \nendometriosis patients and 400 controls. \n* Information obtained from 189 with endometriosis and 384 controls.\n** Information obtained from 152 with endometriosis and 350 controls.\n*** Based on data from working women, respectively 157 and 215.\nVariables\nEndometrio-\nsis\n    (n = 200)\nControl\n(n = 400)\np-va-\nlue\nAt least one complication, n (%) 56 (28) 103 (25.8) 0.556\nSevere complications, n (%) 16 (8) 25 (6.3)*** 0.423\nUrinary tract injury, n (%) 3 (1.5) 6 (1.5) 1.000\nIntestinal injury, n (%) 13 (6.5) 22 (5.5) 0.622\nOther complications\nDrop in hemoglobin levels, g/dl \n(mean ± SD)* 2.42 ± 1.31 2.19 ± 1.28 0.152\nHematoma, n (%) 8 (4) 13 (3.2) 0.637\nWound infection, n (%) 11 (5.5) 9 (2.2) 0.037\nFever > 38°C, n (%)** 10 (5.4) 10 (2.7) 0.105\nAntibiotic treatment, n (%) 34(17) 84 (21) 0.245\nBlood transfusion, n (%) 6 (3.0) 18 (4.5) 0.337\nReoperation within 60 days, n (%) 4 (2) 10 (2.5) 0.702\nTable 5: Complication rate at operation for endometriosis (N = 200) and \ncontrols (N = 400) within 60 days after surgery.\n* Information obtained from 96 with endometriosis and 185 controls.\n** Information obtained from 186 with endometriosis and 374 controls.\n*** Three controls had urinary tract as well as intestinal injuries.\n\nPage 4 of 4Citation: Skrede S, Skaravik TS, Moen MH (2014) Endometriosis does not Increase Risk of Surgical Complications. A Comparative \nStudy. SOJ Surgery 1(2), 4.\nEndometriosis does not Increase Risk of Surgical Complications a Comparative Study\n Copyright: \n© 2014 Moen et al.\nor greater blood loss.  Fever > 38°C was, however, not more \ncommon in the endometriosis group indicating that the infections \nwere mild.\nPostoperative stay in hospital was almost the same in the \ntwo groups, a median of three days. Maytham and co-workers [6] \nalso presented median post-operative hospital stay of three days. \nBoth groups were given sick leave for 3-4 weeks on average, \nindicating a similar postoperative recovery. 46.3% in the control \ngroup did not work versus 21.5% of the endometriosis group, \nreflecting the age difference between the younger patient group \nand the older control group.\nConclusion\nOur data indicate that there is no greater risk of complications \nin operations performed for endometriosis than in similar \noperations for other benign diseases despite a higher rate of \nrepeated surgery and thus the need for adhesiolysis. It is possible \nthat the considerable experience of our department, being part \nof a university hospital offering secondary as well as tertiary \ngynecological services, has considerable experience which might \nhave affected the results. However, we can reassure our patients \nthat surgery for endometriosis does not have a higher risk of \ncomplications than operations for other conditions.\nReferences\n1. Giudice LC. Clinical practice: endometriosis. N Engl J Med. 2010; 362: \n2389-2398. doi: 10.1056/NEJMcp1000274.\n2. Johnson NP, Hummelshoj L. Consensus on current management of \nendometriosis. for the World Endometriosis Society Montpellier \nConsortium. Hum Reprod. 2013; 28: 1552-1568. doi: 10.1093/\nhumrep/det050.\n3. Fagervold B, Jenssen M, Hummelshoj L, Moen MH. Life after a diagnosis \nwith endometriosis-a 15 years follow-up study. Acta Obstet Gynecol \nScand. 2009; 88(8): 914-919. doi: 10.1080/00016340903108308. \n4. Ruffo G, Scopelliti F, Scioscia M, Ceccaroni M, Mainardi P, Minelli L. \nLaparoscopic colorectal resection for deep infiltrating endometriosis: \nanalysis of 436 cases.  Surg Endosc. 2009; 24: 63-67. doi: 10.1007/\ns00464-009-0517-0.\n5. Campagnacci R, Perretta S, Guerrieri M, Paganini AM, De Sanctis A, \nCiavattini A, et al. Laparoscopic colorectal resection for endometriosis. \nSurg Endosc. 2005; 19: 662-4.\n6. Maytham G, Dowson H, Levy B, Kent A, Rockall T. Laparoscopic \nExcision of Rectovaginal Endometriosis: Report of a prospective study \nand review of the literature. Colorectal Dis. 2010; 12: 1105-1112. doi: \n10.1111/j.1463-1318.2009.01993.x.\n7. Slack A, Child T, Lindsey I, Kennedy S, Cunningham C, Mortensen N, \net al. Urological and colorectal complications following surgery for \nrectovaginal endometriosis. BJOG. 2007;114: 1278-82.\n8. Jacobson TZ, Duffy JM, Barlow D, Koninckx PR, Garry R. Laparoscopic \nsurgery for pelvic pain associated with endometriosis. Cochrane \nDatabase of Systematic Reviews. 2009; (4): CD001300. doi: \n10.1002/14651858.CD001300.pub2.\n9. Moen MH, Thomsen MW. Malpractice claims concerning endometriosis. \nProceedings of the 10\nth  World congress on endometriosis, March \n2008, Melbourne. \n10. Revised American Society for Reproductive Medicine classification of \nendometriosis: 1996. Fertil Steril. 1997; 67: 817-821.\n11. NOMESCO Classification of Surgical Procedures. [Cited 2014 \nSeptember]; Available from: http://nowbase.org/~/media/\nProjekt%20sites/Nowbase/Publikationer/NCSP/NCSP%201_16.ashx \n12. Spilsbury K, Hammond I, Bulsara M, Semmens JB. Morbidity outcomes \nof 78,577 hysterectomies for benign reasons over 23 years. BJOG. \n2008; 115: 1473-1483. doi: 10.1111/j.1471-0528.2008.01921.\n13. Worley MJ, Slomovitz BM, Ramirez PT. Complications of laparoscopy \nin benign and oncologic gynecological surgery. Rev Obstet Gynecol. \n2009; 2:169-175.\n14. Rettenmaier CR, Rettenmaier NB, Abaid LN, Brown JV, Micha JP, \nMendivil AA, et al. The incidence of genotourinary and gastrointestinal \ncomplications in open and endoscopic gynecologic cancer surgery. \nOncology.  2014; 86 (5-6) :303-307. doi: 10.1159/000360294.","source_license":"CC0","license_restricted":false}