Title: Deep endometriosis: definition, diagnosis, and treatment
Abstract: Deep endometriosis, defined as adenomyosis externa, mostly presents as a single nodule, larger than 1 cm in diameter, in the vesicouterine fold or close to the lower 20 cm of the bowel. When diagnosed, most nodules are no longer progressive. In >95% of cases, deep endometriosis is associated with very severe pain (in >95%) and is probably a cofactor in infertility. Its prevalence is estimated to be 1% –2%. Deep endometriosis is suspected clinically and can be confirmed by ultrasonography or magnetic resonance imaging. Contrast enema is useful to evaluate the degree of sigmoid occlusion. Surgery requires expertise to identify smaller nodules in the bowel wall, and difficulty increases with the size of the nodules. Excision is feasible in over 90% of cases often requiring suture of the bowel muscularis or full-thickness defects. Segmental bowel resections are rarely needed except for sigmoid nodules. Deep endometriosis often involves the ureter causing hydronephrosis in some 5% of cases. The latter is associated with 18% ureteral lesions. Deep endometriosis surgery is associated with late complications such as late bowel and ureteral perforations, and recto-vaginal and uretero-vaginal fistulas. Although rare, these complications require expertise in follow-up and laparoscopic management. Pain relief after surgery is excellent and some 50% of women will conceive spontaneously, despite often severe adhesions after surgery. Recurrence of deep endometriosis is rare. In conclusion, defined as adenomyosis externa, deep endometriosis is a rarely a progressive and recurrent disease. The treatment of choice is surgical excision, while bowel resection should be avoided, except for the sigmoid. Deep endometriosis, defined as adenomyosis externa, mostly presents as a single nodule, larger than 1 cm in diameter, in the vesicouterine fold or close to the lower 20 cm of the bowel. When diagnosed, most nodules are no longer progressive. In >95% of cases, deep endometriosis is associated with very severe pain (in >95%) and is probably a cofactor in infertility. Its prevalence is estimated to be 1% –2%. Deep endometriosis is suspected clinically and can be confirmed by ultrasonography or magnetic resonance imaging. Contrast enema is useful to evaluate the degree of sigmoid occlusion. Surgery requires expertise to identify smaller nodules in the bowel wall, and difficulty increases with the size of the nodules. Excision is feasible in over 90% of cases often requiring suture of the bowel muscularis or full-thickness defects. Segmental bowel resections are rarely needed except for sigmoid nodules. Deep endometriosis often involves the ureter causing hydronephrosis in some 5% of cases. The latter is associated with 18% ureteral lesions. Deep endometriosis surgery is associated with late complications such as late bowel and ureteral perforations, and recto-vaginal and uretero-vaginal fistulas. Although rare, these complications require expertise in follow-up and laparoscopic management. Pain relief after surgery is excellent and some 50% of women will conceive spontaneously, despite often severe adhesions after surgery. Recurrence of deep endometriosis is rare. In conclusion, defined as adenomyosis externa, deep endometriosis is a rarely a progressive and recurrent disease. The treatment of choice is surgical excision, while bowel resection should be avoided, except for the sigmoid. Discuss: You can discuss this article with its authors and with other ASRM members at http://fertstertforum.com/koninckxpr-deep-endometriosis-diagnosis-treatment/ Discuss: You can discuss this article with its authors and with other ASRM members at http://fertstertforum.com/koninckxpr-deep-endometriosis-diagnosis-treatment/ The number of articles on endometriosis has increased exponentially over recent decades, creating problems (1Koninckx P.R. Batt R.E. Hummelshoj L. McVeigh E. Ussia A. Yeh J. The elephant in the room: quality control of endometriosis data.J Minim Invasive Gynecol. 2010; 17: 637-640Abstract Full Text Full Text PDF PubMed Scopus (6) Google Scholar) of quality. Furthermore, evidence-based medicine (EBM), which aims to apply the best available evidence gained from scientific methods, has the tendency to consider everything that is not proven as untrue, thus disregarding valuable observational information. This contributes to controversy, especially in surgery. Indeed, randomized controlled trials (RCTs) for rare and complex pathologies (e.g., hemorrhagic ascites or müllerianosis) are practically impossible to conduct because of the numbers required (2Ussia A. Betsas G. Corona R. De C.C. Koninckx P.R. Pathophysiology of cyclic hemorrhagic ascites and endometriosis.J Minim Invasive Gynecol. 2008; 15: 677-681Abstract Full Text Full Text PDF PubMed Scopus (24) Google Scholar, 3Batt R.E. Smith R.A. Buck Louis G.M. Martin D.C. Chapron C. Koninckx P.R. et al.Mullerianosis.Histol Histopathol. 2007; 22: 1161-1166PubMed Google Scholar). Surgical series always evaluate both the technique and the skill of the surgeon, whereas blinding is difficult to implement. For deep endometriosis, surgical series often deal with the entire range of this highly variable pathology, which breaches the strict inclusion and exclusion criteria of most RCTs. Moreover, we lack an animal model for this disease (4Dehoux J.P. Defrere S. Squifflet J. Donnez O. Polet R. Mestdagt M. et al.Is the baboon model appropriate for endometriosis studies?.Fertil Steril. 2011; 96: 728-733Abstract Full Text Full Text PDF PubMed Scopus (26) Google Scholar). Most published series are small and nonrandomized. They all reflect a referral bias and choices made concerning diagnosis and surgery by a specific group. This, together with the fact that deep endometriosis is clinically highly variable, prevents a meta-analysis, or even a systematic review, of simple but obvious questions such as the importance of size, localization, and depth of infiltration. In addition, many problems are too rare for meaningful conclusions. Indeed, to collect a series of only 80 cases of hydronephrosis, 20 years and 2400 interventions were needed (5De C.C. Ussia A. Koninckx P.R. Laparoscopic ureteral repair in gynaecological surgery.Curr Opin Obstet Gynecol. 2011; 23: 296-300PubMed Google Scholar). Therefore, in the light of available data we chose not to write a systematic review because this would only highlight controversy while everything considered “unproven” would be left out. Instead, an authority-based review is presented, reflecting the joint surgical experience of >8,000 cases of deep endometriotic nodules and numerous discussions during congresses and live surgery. Deep endometriosis was defined arbitrarily as endometriosis infiltrating the peritoneum by >5 mm (6Koninckx P.R. Martin D.C. Deep endometriosis: a consequence of infiltration or retraction or possibly adenomyosis externa?.Fertil Steril. 1992; 58: 924-928Abstract Full Text PDF PubMed Google Scholar). Microscopically, this definition included both adenomyosis externa and deeper typical lesions (described as type I). Typical lesions are multifocal and surgically less demanding. Nodules of adenomyosis externa (type II and type III lesions) are generally unique at the level of the rectum, rectosigmoid, sigmoid, or vesicouterine fold. Occasionally, two nodules are present, whereas three nodules are extremely rare (in the experience of the authors, <1 in 1,000). The difficulty of accurate depth estimation, has lead to the inclusion of variable numbers of typical lesions in most published series, the percentages of which differs between groups. This has created confusion in the literature because the pathology of the lesions is rarely mentioned. In addition, that deep endometriosis surgery has become a skill label has contributed to the problem of including typical lesions. We therefore suggest that deep endometriosis should be pathologically defined as adenomyosis externa—suggested as early as 1990 (7Cornillie F.J. Oosterlynck D. Lauweryns J.M. Koninckx P.R. Deeply infiltrating pelvic endometriosis: histology and clinical significance.Fertil Steril. 1990; 53: 978-983Abstract Full Text PDF PubMed Scopus (515) Google Scholar)—making it a homogeneous entity. In this article, this definition of adenomyosis externa will be used. The prevalence of deep endometriosis varies according to recognition and diagnosis, but it is estimated to be just a few percent of the population (8Koninckx P.R. Biases in the endometriosis literature. Illustrated by 20 years of endometriosis research in Leuven.Eur J Obstet Gynecol Reprod Biol. 1998; 81: 259-271Abstract Full Text Full Text PDF PubMed Scopus (35) Google Scholar). Most women have severe pain, but an estimated 5% are pain free (no hard data available). After surgery, half will conceive spontaneously (9Donnez J. Squifflet J. Complications, pregnancy and recurrence in a prospective series of 500 patients operated on by the shaving technique for deep rectovaginal endometriotic nodules.Hum Reprod. 2010; 25: 1949-1958Crossref PubMed Scopus (216) Google Scholar), suggesting a cause-and-effect relationship between deep endometriosis and infertility. During the past two decades, the prevalence has apparently increased. Based on our experience in developing centers for deep endometriosis surgery in Oxford, Rome, and Strasbourg, we consider that this reflects growing awareness and referral. In addition, the inclusion of larger typical lesions contributes to this apparent increase. The pathophysiology of endometriosis remains a subject of debate. It is still unclear whether endometrial and endometriotic cells are genetically different (10Koninckx P.R. Barlow D. Kennedy S. Implantation versus infiltration: the Sampson versus the endometriotic disease theory.Gynecol Obstet Invest. 1999; 47: 3-9Crossref PubMed Scopus (66) Google Scholar), or whether observed differences are the consequence of different environments (11Koninckx P.R. Kennedy S.H. Barlow D.H. Endometriotic disease: the role of peritoneal fluid.Hum Reprod Update. 1998; 4: 741-751Crossref PubMed Scopus (220) Google Scholar, 12Koninckx P.R. Biases in the endometriosis literature—illustrated by 20 years of endometriosis research in Leuven.Eur J Obstet Gynecol Reprod Biol. 1998; 81: 259-271Abstract Full Text Full Text PDF PubMed Scopus (22) Google Scholar) or of preexisting immunologic defects (13Oosterlynck D.J. Meuleman C. Waer M. Koninckx P.R. CO2-laser excision of endometriosis does not improve the decreased natural killer activity.Acta Obstet Gynecol Scand. 1994; 73: 333-337Crossref PubMed Scopus (23) Google Scholar). The fact that deep and cystic endometriosis are both clonal in origin, strongly (14Nabeshima H. Murakami T. Yoshinaga K. Sato K. Terada Y. Okamura K. Analysis of the clonality of ectopic glands in peritoneal endometriosis using laser microdissection.Fertil Steril. 2003; 80: 1144-1150Abstract Full Text Full Text PDF PubMed Scopus (28) Google Scholar, 15Wu Y. Basir Z. Kajdacsy-Balla A. Strawn E. Macias V. Montgomery K. et al.Resolution of clonal origins for endometriotic lesions using laser capture microdissection and the human androgen receptor (HUMARA) assay.Fertil Steril. 2003; 79: 710-717Abstract Full Text Full Text PDF PubMed Scopus (104) Google Scholar, 16Jimbo H. Hitomi Y. Yoshikawa H. Yano T. Momoeda M. Sakamoto A. et al.Evidence for monoclonal expansion of epithelial cells in ovarian endometrial cysts.Am J Pathol. 1997; 150: 1173-1178PubMed Google Scholar) suggests some underlying genetic mutation. Associated differences in the endometrium appear to reflect a genetic predisposition. Deep endometriosis should not be considered a progressive disease. Although an endometriotic lesion must clearly have been growing at some point, we challenge the concept of unavoidable progression after implantation because to our knowledge, a transition from typical to cystic or deep lesions was never observed. Deep endometriotic lesions that were not removed after diagnosis were not found to be progressive, some with a follow-up of 10 years. Although exact data are not available and mainly reflect nodules that are not painful, the joint experience of the authors suggests progression in only 1 nodule out of 20. This concept of no or low progression is moreover consistent with clinical observations that most women experience severe pain for many years, often decades. In addition, the diameter of the nodules does not increase with age or duration of symptoms (unpublished observations). Indirect evidence in the Leuven area confirms this concept. Indeed, Ivo Brosens (personal communication) investigated patients for endometriosis in the early 1980s. These women, diagnosed at the time with typical and cystic endometriosis, were not the same as those in whom deep endometriosis was diagnosed in the 1990s by PK or JD working in the same area. Deep endometriosis should not be considered a recurrent disease. Although surgery is highly variable and good prospective data are lacking, recurrence rates of confirmed deep endometriosis are convincingly low, that is, <5% (17Roman H. Vassilieff M. Gourcerol G. Savoye G. Leroi A.M. Marpeau L. et al.Surgical management of deep infiltrating endometriosis of the rectum: pleading for a symptom-guided approach.Hum Reprod. 2011; 26: 274-281Crossref PubMed Scopus (133) Google Scholar, 18De Cicco C. Corona R. Schonman R. Mailova K. Ussia A. Koninckx P. Bowel resection for deep endometriosis: a systematic review.Br J Obstet Gynaecol. 2011; 118: 285-291Crossref Scopus (237) Google Scholar). By clinical examination, only 50% of deep endometriotic nodules >3 cm in diameter were diagnosed in the mid-1990s (19Koninckx P.R. Meuleman C. Oosterlynck D. Cornillie F.J. Diagnosis of deep endometriosis by clinical examination during menstruation and plasma CA-125 concentration.Fertil Steril. 1996; 65: 280-287Abstract Full Text PDF PubMed Google Scholar). With experience and awareness, the clinical diagnosis has probably improved. The most important conclusion, however, that the vast majority of deep endometriotic lesions will not be diagnosed by clinical examination, remains valid. Deep endometriosis should be suspected in all women with invalidating hypogastric pain, especially dysmenorrhea, deep dyspareunia, severe chronic pain, mictalgia, and dyschezia. Most pathognomonic signs are severe dyschezia, menstrual blood on stools, menstrual diarrhea, severe menstrual mictalgia, and radiation of pain to the perineum (unpublished data). Although solid data linking these symptoms to size and localization of deep endometriosis are lacking, clinical symptoms remain key to suspecting deep endometriosis and deciding to perform surgery. Clinical suspicion of rectal or rectosigmoid deep endometriosis can be confirmed by vaginal ultrasonography. The sensitivity and specificity of ultrasonography in the diagnosis of deep endometriosis remains unclear, and although reported to be >85% and even close to 100% (20Hudelist G. English J. Thomas A.E. Tinelli A. Singer C.F. Keckstein J. Diagnostic accuracy of transvaginal ultrasound for non-invasive diagnosis of bowel endometriosis: systematic review and meta-analysis.Ultrasound Obstet Gynecol. 2011; 37: 257-263Crossref PubMed Scopus (225) Google Scholar), operators were never blinded to the clinical symptoms and rarely to the clinical examination. In addition, data linking sensitivity and specificity to the diameter and localization of the nodules are lacking. Most important, however, is that the accuracy of ultrasonography varies according to the expertise of the ultrasonographer. Answers to important questions such as sensitivity and specificity in the absence of clinical suspicion, or after a negative clinical exam, are missing. We suggest that ultrasonography is a useful tool when performed by an experienced ultrasonographer in dialogue with the clinician or surgeon. Conversely, ultrasonographic diagnosis of deep endometriosis in the absence of clinical symptoms should not be an indication for surgery. Although rare cases with silent hydronephrosis without clinical symptoms at routine ultrasonographic examination could contradict this statement, none of the authors have found this pathology, emphasizing that it must be extremely rare. Moreover, ultrasonographic examinations are not useful for the diagnosis of sigmoid endometriosis (20Hudelist G. English J. Thomas A.E. Tinelli A. Singer C.F. Keckstein J. Diagnostic accuracy of transvaginal ultrasound for non-invasive diagnosis of bowel endometriosis: systematic review and meta-analysis.Ultrasound Obstet Gynecol. 2011; 37: 257-263Crossref PubMed Scopus (225) Google Scholar). Clinical suspicion can be confirmed by magnetic resonance imaging (MRI). Magnetic resonance imaging might be less operator dependent and can also provide information about lesions at the level of the sigmoid, but the conclusions reached are similar to those of ultrasonographic examination (21Saba L. Guerriero S. Sulcis R. Pilloni M. Ajossa S. Melis G. et al.MRI and "tenderness guided" transvaginal ultrasonography in the diagnosis of recto-sigmoid endometriosis.J Magn Reson Imaging. 2012; 35: 352-360Crossref PubMed Scopus (72) Google Scholar, 22Bazot M. Gasner A. Lafont C. Ballester M. Darai E. Deep pelvic endometriosis: limited additional diagnostic value of postcontrast in comparison with conventional MR images.Eur J Radiol. 2011; 80: e331-e339Abstract Full Text Full Text PDF PubMed Scopus (57) Google Scholar, 23Bazot M. Darai E. Value of transvaginal sonography in assessing severe pelvic endometriosis.Ultrasound Obstet Gynecol. 2010; 36: 134-135Crossref PubMed Scopus (7) Google Scholar, 24Bazot M. Lafont C. Rouzier R. Roseau G. Thomassin-Naggara I. Darai E. Diagnostic accuracy of physical examination, transvaginal sonography, rectal endoscopic sonography, and magnetic resonance imaging to diagnose deep infiltrating endometriosis.Fertil Steril. 2009; 92: 1825-1833Abstract Full Text Full Text PDF PubMed Scopus (315) Google Scholar). Typical images of a contrast enema can occasionally confirm a sigmoid or high rectosigmoid lesion. Colonoscopy is almost invariably negative. Only in rare cases of very large nodules (Fig. 1) with a high degree of bowel occlusion will colonoscopy be positive. The prevalence is estimated to be <5 in 1,000 cases. CA125 measurement is not very useful for the management of deep endometriosis, although sensitivity and specificity are >80% (25Muyldermans M. Cornillie F.J. Koninckx P.R. CA125 and endometriosis.Hum Reprod Update. 1995; 1: 173-187Crossref PubMed Scopus (52) Google Scholar). In conclusion, deep endometriosis is suspected or diagnosed clinically and the clinical suspicion can be confirmed by ultrasonography or MRI. Most important is close cooperation and dialogue between the surgeon and imaging specialist. The decision to perform surgery for deep endometriosis is mainly clinical. Ultrasonography and MRI can be useful tools to have a preoperative estimation of the size and lateral extension of lesions, larger lesions being more at risk of causing urinary retention after surgery (26Ballester M. Santulli P. Bazot M. Coutant C. Rouzier R. Darai E. Preoperative evaluation of posterior deep-infiltrating endometriosis demonstrates a relationship with urinary dysfunction and parametrial involvement.J Minim Invasive Gynecol. 2011; 18: 36-42Abstract Full Text Full Text PDF PubMed Scopus (38) Google Scholar). It remains debated (27Abrao M.S. Podgaec S. Dias Jr., J.A. Averbach M. Silva L.F. Marino de C.F. Endometriosis lesions that compromise the rectum deeper than the inner muscularis layer have more than 40% of the circumference of the rectum affected by the disease.J Minim Invasive Gynecol. 2008; 15: 280-285Abstract Full Text Full Text PDF PubMed Scopus (80) Google Scholar), however, to what extent preoperative ultrasonography or MRI should influence the decision to perform surgery, or indeed the type of intervention to undertake for deep endometriosis. Once the decision to perform surgery has been taken, a contrast enema is important, because it is the only examination that allows evaluation of the degree and length of bowel occlusion at the level of the sigmoid or high rectosigmoid. For the rectum, a contrast enema rarely provides additional information. Hydronephrosis should be excluded before surgery because it is associated with 18% of ureteral lesions during surgery and requires a preoperative ureteral stent (28De Cicco C. Schonman R. Craessaerts M. Van C.B. Ussia A. Koninckx P.R. Laparoscopic management of ureteral lesions in gynecology.Fertil Steril. 2009; 92: 1424-1427Abstract Full Text Full Text PDF PubMed Scopus (37) Google Scholar). A bowel preparation has traditionally been routinely given to all women scheduled for deep endometriosis surgery. Whether a bowel preparation is necessary for bowel resection has recently been challenged (29Cao F. Li J. Li F. Mechanical bowel preparation for elective colorectal surgery: updated systematic review and meta-analysis.Int J Colorectal Dis. 2012; 27: 803-810Crossref PubMed Scopus (110) Google Scholar, 30Cohen S.L. Einarsson J.I. The role of mechanical bowel preparation in gynecologic laparoscopy.Rev Obstet Gynecol. 2011; 4: 28-31PubMed Google Scholar, 31Fanning J. Valea F.A. Perioperative bowel management for gynecologic surgery.Am J Obstet Gynecol. 2011; 205: 309-314Abstract Full Text Full Text PDF PubMed Scopus (40) Google Scholar, 32Galandiuk S. Fry D.E. Polk Jr., H.C. Is there a role for bowel preparation and oral or parenteral antibiotics in infection control in contemporary colon surgery?.Adv Surg. 2011; 45: 131-140Abstract Full Text Full Text PDF PubMed Scopus (3) Google Scholar). It is unclear if these data can be extrapolated to conservative deep endometriosis excision, but evidence suggests that at least preoperative antibiotics should be given (30Cohen S.L. Einarsson J.I. The role of mechanical bowel preparation in gynecologic laparoscopy.Rev Obstet Gynecol. 2011; 4: 28-31PubMed Google Scholar). Transrectal MRI and transrectal ultrasonography have also been used to evaluate the depth of infiltration (33Hudelist G. Tuttlies F. Rauter G. Pucher S. Keckstein J. Can transvaginal sonography predict infiltration depth in patients with deep infiltrating endometriosis of the rectum?.Hum Reprod. 2009; 24: 1012-1017Crossref PubMed Scopus (94) Google Scholar, 34Bassi M.A. Podgaec S. Dias Jr., J.A. D'Amico F.N. Petta C.A. Abrao M.S. Quality of life after segmental resection of the rectosigmoid by laparoscopy in patients with deep infiltrating endometriosis with bowel involvement.J Minim Invasive Gynecol. 2011; 18: 730-733Abstract Full Text Full Text PDF PubMed Scopus (71) Google Scholar, 35Goncalves M.O. Podgaec S. Dias Jr., J.A. Gonzalez M. Abrao M.S. Transvaginal ultrasonography with bowel preparation is able to predict the number of lesions and rectosigmoid layers affected in cases of deep endometriosis, defining surgical strategy.Hum Reprod. 2010; 25: 665-671Crossref PubMed Scopus (135) Google Scholar) and radial extension of deep endometriotic nodules. Infiltration up to the mucosa and invasion over >50% of the circumference were suggested as an indication for bowel resection (27Abrao M.S. Podgaec S. Dias Jr., J.A. Averbach M. Silva L.F. Marino de C.F. Endometriosis lesions that compromise the rectum deeper than the inner muscularis layer have more than 40% of the circumference of the rectum affected by the disease.J Minim Invasive Gynecol. 2008; 15: 280-285Abstract Full Text Full Text PDF PubMed Scopus (80) Google Scholar, 35Goncalves M.O. Podgaec S. Dias Jr., J.A. Gonzalez M. Abrao M.S. Transvaginal ultrasonography with bowel preparation is able to predict the number of lesions and rectosigmoid layers affected in cases of deep endometriosis, defining surgical strategy.Hum Reprod. 2010; 25: 665-671Crossref PubMed Scopus (135) Google Scholar), but this remains a subject of debate (36Koninckx P.R. De C.C. Schonman R. Corona R. Betsas G. Ussia A. The recent article "Endometriosis lesions that compromise the rectum deeper than the inner muscularis layer have more than 40% of the circumference of the rectum affected by the disease.".J Minim Invasive Gynecol. 2008; 15: 774-775Abstract Full Text Full Text PDF PubMed Google Scholar). In conclusion, before surgery, hydronephrosis should be identified because it requires preoperative ureteral stenting (28De Cicco C. Schonman R. Craessaerts M. Van C.B. Ussia A. Koninckx P.R. Laparoscopic management of ureteral lesions in gynecology.Fertil Steril. 2009; 92: 1424-1427Abstract Full Text Full Text PDF PubMed Scopus (37) Google Scholar). Any partial bowel occlusion should also be diagnosed before surgery. As will be discussed, it remains unclear to what extent preoperative bowel examination should influence the decision regarding the type of surgery. We suggest that women with a bowel occlusion of >50% or longer than 2–3 cm should be scheduled for elective bowel resection. All other women should undergo excision of the nodule. If during surgery the nodule is found to be too big or invading the bowel wall too deeply, the skill and expertise of the surgeon should be weighted against the difficulty of discoid excision. In groups performing bowel resections liberally, preoperative management based on imaging was found to be highly variable (18De Cicco C. Corona R. Schonman R. Mailova K. Ussia A. Koninckx P. Bowel resection for deep endometriosis: a systematic review.Br J Obstet Gynaecol. 2011; 118: 285-291Crossref Scopus (237) Google Scholar), while ureteral stents were often inserted systematically. Completeness of surgery with removal of all endometriosis sounds like a precept, as used in cancer surgery. However, evidence that endometriosis surgery needs to be 100% complete is lacking, although circumstantial evidence of the opposite exists. First of all, it is close to impossible to remove all endometrial/endometriotic cells from all sites. The discussion whether or not to remove all subtle or microscopic endometriosis is beyond the scope of this article. In >10% of cases of deep endometriosis, lymph nodes contain endometrial/endometriotic cells (37Gong Y. Tempfer C.B. Regional lymphatic spread in women with pelvic endometriosis.Med Hypotheses. 2011; 76: 560-563Abstract Full Text Full Text PDF PubMed Scopus (12) Google Scholar, 38Namkung J. Kim S.J. Kim J.H. Kim J. Hur S.Y. Rectal endometriosis with invasion into lymph nodes.J Obstet Gynaecol Res. 2011; 37: 1117-1121Crossref PubMed Scopus (7) Google Scholar, 39Tempfer C.B. Wenzl R. Horvat R. Grimm C. Polterauer S. Buerkle B. et al.Lymphatic spread of endometriosis to pelvic sentinel lymph nodes: a prospective clinical study.Fertil Steril. 2011; 96: 692-696Abstract Full Text Full Text PDF PubMed Scopus (23) Google Scholar). To our knowledge, these lymph nodes never caused any clinical symptoms and fortunately systematic pelvic lymph node resection was not proposed. Second, deep endometriosis is surrounded by a fibrotic layer. It is unclear whether this layer should be removed or may be left behind. In the absence of evidence, it is remarkable that most of us have become less aggressive surgically than 10 years ago, as discussed at a meeting in Atlanta between Camran Nezhat and the present authors. Third, recurrence rates of deep endometriosis requiring surgery are so low that it would be virtually impossible to demonstrate the need for complete versus near complete excision. Indeed, an increased recurrence rate from 1% to a few percent would be hard to prove. Finally, it remains unclear whether deep endometriotic nodules not causing pain should be excised when there is no evidence of progression. Moreover, many of these nodules probably go unnoticed, without doing any apparent harm. Absence of evidence that all remaining endometriotic cells should be removed to reduce recurrence rates or improve pain or infertility outcome is very different from carrying out incomplete surgery by leaving a large part of the nodule behind. Clinical impressions confirmed by reviewing our database suggest that the most difficult surgeries of long duration were indeed those performed in women who had been operated on before, leaving deep endometriosis behind because of massive adhesions. Similar observations were made in women who had undergone several IVF cycles with oocyte pickup, and puncture through a deep endometriotic nodule. We therefore suspect that trauma to endometriotic nodules could reactivate the disease, causing growth and massive adhesions. Surgery of “fresh” nodules, never previously operated, is anticipated as being technically much easier. In conclusion, in the absence of solid evidence, we suggest that deep endometriosis surgery should be visually complete, but at the level of the bowel, a rim of fibrosis can be left behind. Because we found most recurrences at the posterior fornix of the vagina, and because the vaginal cuff heals well, we specifically emphasize completeness at this level. Excision of deep endometriosis can be technically demanding and the surgeon should balance his skills against the anticipated difficulty and duration of surgery. A technically difficult and long surgery should be expected when the nodule is >3 cm in diameter, when it is firmly attached to the ischial spine, when localized in the sigmoid, or when adhesions are expected because of previous incomplete surgery or IVF (unpublished data from the Leuven database, confirmed clinically by all authors). Especially when surgery exceeds 4–5 hours, the surgeon should be aware that fatigue can impair judgment (40Schonman R. De C.C. Corona R. Soriano D. Koninckx P.R. Accident analysis: factors contributing to a ureteric injury during deep endometriosis surgery.Br J Obstet Gynaecol. 2008; 115: 1611-1615Crossref Scopus (13) Google Scholar). This highlights the need for a team wi