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Incidence of intestinal endometriosis
Although the most common sites of endometriosis are the ovaries, anterior and posterior cul-de-sac, broad ligaments, uterosacral ligaments, uterus, and fallopian tubes, endometriosis can occur elsewhere. Extra genital endo-metriosis can be present on the intestines, bladder, ureters, rectovaginal septum, and diaphragm.14
The most common location of extragenital endometriosis is the bowel, which account for 80% of extragenital endometriosis.15 The gastrointestinal (GI) tract is involved in endometriosis in 3% to 37% of cases.16,17 Intestinal endometriosis can be present from the anal canal to the small intestine; however, the most frequent location of involvement is the rectum and sigmoid colon. In one study of 1573 patients with endometriosis, 5.4% had intestinal involvement, and 65.0% of those had endometriosis of the rectum and rectosigmoid colon.18 The remainder of locations are the rectovaginal septum (12.0%), cecum (2.0%), and appendix (3.0%).18-21
Symptoms of intestinal endometriosis
One third of patients with intraoperatively diagnosed sigmoidal endo-metriosis are symptomatic. These symptoms include crampy pain, flatulence, painful tenesmus, hyper-peristalsis, progressive constipation, diarrhea alternating with constipation, and occasionally rectal bleeding.2,15 These symptoms usually occur cyclically; either at the time of menstruation or at the same time of the cycle. However, some patients with GI endometriosis will have non-cyclical symptoms.
Appendiceal endometriosis can mimic acute appendicitis and can be partially responsible for chronic pelvic pain.22 Histologically proven appendiceal endometriosis is present in 49.0% of appendices removed in patients with endometriosis.23
Bowel obstruction is a rare complication of intestinal endometriosis. Studies have reported the incidence of bowel obstruction associated with endo-metriosis to be between 8.0% - 12.0%.17,18,24 In a patient who is diagnosed with a bowel obstruction, endometriosis should be considered when dyspareunia, dysmenorrhea, and/or infertility also are present.
Diagnosis
The preoperative diagnosis of intestinal endometriosis is difficult. In a patient with known or suspected endometriosis and intestinal symptoms, the clinician should consider the possibility of intestinal endometriosis and preoperative counseling should be reflective.
Imaging and preoperative diagnostic procedures have not proven to be reliable in the diagnosis of intestinal endometriosis. In only 43.0% of patients with colorectal endometriosis was bowel involvement suspected preoperatively.25 Colonic involvement is difficult to diagnosis preoperatively, given that implants rarely invade to the mucosa.26
The physical examination often shows no abnormalities in endometriosis. However, tenderness on palpation of the posterior fornix, posterior cul-de-sac, or uterosacral ligaments is suggestive of endometriosis. Other findings on physical examination consistent with endometriosis are palpable tender nodules on the uterosacral ligaments, cul-de-sac, or rectovaginal septum, pain with movement of the uterus, tender, enlarged adnexal masses, and a fixed uterus and/or adnexa.27 The ability to detect infiltrative nodules is improved if the examination is performed during menstruation.28
When clinical evidence exists to suggest the presence of deeply infiltrating endometriosis, by history or physical examination, imaging studies can be used to map the extent of the disease. Magnetic resonance imaging (MRI) and ultrasound (transvaginal and transrectal) may disclose extra genital locations of endometriosis. Again, despite preoperative investigation, less than half of the patients reported to have intestinal endometriosis at surgery will have been diagnosed preoperatively.25
Treatment
Invasive endometriosis lesions on the bowel that invade the muscular layer undergo cellular hyperplasia and fibrosis; therefore, they are resistant to medical management. Approximately 10.0% of women with intestinal endometriosis develop symptoms after menopause or after bilateral salpingooophorectomy.15 Hence, surgical management of bowel endometriosis is the preferred method of treatment.
For many surgeons, laparotomy remains the preferred modality for treatment of intestinal disease. Until recently, laparotomy was thought to be the only safe way to treat bowel endometriosis. Multiple studies have shown that laparoscopic procedures, compared to open procedures, have a shorter recover time, less adhesion formation, and better visualization,5,8-10 all of which are critical to the successful and complete treatment of endometriosis. The first report of laparoscopic treatment of endometriosis was published in 1986.5 Subsequent to this report, multiple studies have been published that confirm the laparoscopic treatment of intestinal endometriosis is both safe and effective.11,12,19,26,29,30
Surgical procedures
Although similar procedures for the laparoscopic treatment of bowel endometriosis have been described, the procedures presented here have been tested and are safe and effective for treatment of intestinal endometriosis.
Shaving
Of all the techniques available to remove endometriosis lesions of the bowel, shaving is the least invasive procedure. Bowel shaving is used when the invasive endometriosis lesion has partially invaded the muscular layer, but not the full thickness of the bowel wall. The technique of shaving consists of vaporizing and excision of the lesion, layer-by-layer until normal tissue is reached without full-thickness resection. After removal of the entire lesion, reinforcement serosal sutures are placed, if needed. Following completion of the bowel shaving and placement of the reinforcement sutures, the pelvis is filled with lactated Ringer’s solution, and a sigmoidoscope is used to insufflate the rectosigmoid colon to confirm the closure is airtight, as demonstrated by the absence of air-bubbles.2,31
Disk Excision
Laparoscopic disk excision is a technique used to resect an infiltrating, full-thickness bowel lesion that does not involve more than one third of the circumference of the bowel. Disk excision can be performed intra-abdominally or, if the lesion is in the lower rectum, transanally or transvaginally.
After identifying the lesion and surrounding normal tissue, the lesion is grasped at its proximal end. An incision is made through the bowel serosa and muscularis, and the lumen is entered. Then, the lesion is excised completely from the bowel wall.
After the lesion is excised and removed from the abdomen, the pelvis is copiously irrigated. The bowel reanastomosis is performed using a single layer, transverse closure. Two traction sutures are placed along the transverse limits of the defect, which create a transverse wound when traction is applied. The stay sutures are brought out through the right and left port sites by removing the sleeves and then replacing them, thereby compressing the suture between the sleeve and abdominal wall. The bowel is then repaired using 0 Vicryl (Ethicon, Somerville, NJ, USA) by placing several interrupted, through-and-through sutures in 0.3 cm to 0.6 cm increments until the defect is closed completely. Following closure of the defect, the pelvic cavity is filled with lactated Ringer’s solution and a sigmoidoscope is used to insufflate the rectosigmoid colon to confirm the closure is airtight, demonstrated by the absence of air-bubbles. In addition, the sigmoidoscope is used to ensure no stricture was created by the reanastomosis.19
Anterior Rectal Wall Excision
Laparoscopically assisted anterior rectal wall resection with reanastomosis is another method to resect infiltrative rectosigmoid endometriosis that involves less than one-third of the circumference of the bowel.
The technique described herein involves laparoscopic mobilization of the lower colon, transanal or transvaginal prolapse of the lesion, resection, and reanastomosis. The rectum is mobilized along the rectovaginal septum anteriorly within 2 cm of the anus. Mobilization continues along the left and right pararectal spaces by dividing branches of the hemorrhoidal artery. When the rectum is mobilized sufficiently, the lesion is prolapsed vaginally or anally, and the nodule is excised using an RL30 or RL60 stapler (Ethicon EndoSurgery, Cincinnati, OH, USA). Two staple applications may be required to traverse the width of the involved mucosa. The rectum is returned to the pelvis under direct observation and closure is confirmed by insufflating the rectum while the pelvis is filled with lactated Ringer’s solution.11,30
Segmental Resection
When the infiltrative endometriotic lesion involves more than one-third of the circumference of the bowel, a segmental resection is required. When the rectum is involved, use of a mini-laparotomy for resection and reanastomosis may not be possible given that the rectum is not long enough to reach the anterior abdominal wall. In this case, the lesion can be prolapsed through the rectum or vagina for resection.
In this procedure, the rectum is mobilized, and then prolapsed through the vagina or rectum. The resection is performed to remove the lesion, and then the reanastomosis is completed within the abdomen under laparoscopic guidance.
The rectum is mobilized completely to allow prolapsed of the lesion either transanally or transvaginally. The anterior rectal wall is freed from the vagina along the rectovaginal septum to the pelvic floor. This procedure is done with guidance from an assistant who delineates the rectovaginal septum by placing fingers in the vagina and rectum simultaneously. The rectal mesenteric vasculature dissected laterally and the lateral rectal pedicels are electro-coagulated using bipolar electrocautery. Posteriorly, the avascular presacral space is dissected to the level of the levator ani muscles for complete mobilization of the bowel. The branches of the inferior mesenteric vessels of the bowel segment to be resected are coagulated and transected. The rectum is transected proximal to the lesion, and the proximal stump is prolapsed through the vagina or through the distal rectal stump. A purse-string suture of 2-0 is used on the proximal bowel to secure the opposing anvil of a No. 33 intraluminal stapler (ILS, Ethicon Endosurgery, Cincinnati, OH) to the bowel, and this is returned to the abdomen. The rectal stump that contains the lesion is prolapsed through the anal canal or vagina and transected proximal to the lesion using a RL60 linear stapler (Ethicon EndoSurgery, Cincinnati, OH, USA). The rectal stump is then replaced into the pelvis and the No. 33 ILS stapler (Ethicon EndoSurgery, Cincinnati, OH, USA) is placed into the rectum and the anvil—in the proximal limb—is inserted into the devise laparoscopically. Upon firing of the devise, an end-to-end anastomosis is created. The anastomosis is inspected by proctoscopy. The pelvis is filled with lactated Ringer’s solution and the anastomosis is inspected for leakage. If air leaks are identified, these can be corrected using 2-0 suture placed transanally or laparoscopically.12
An alternative method is resection of the bowel intraabdominally. After complete mobilization of the section to be removed, a 60-mm Endostapler (Ethicon, EndoSurgery, Cincinnati, OH, USA) is placed distal to the lesion and fired. The proximal section of the bowel, including the lesion, is exteriorized through a 2-cm to 3-cm Pfannenstiel incision. The area of the bowel that contains the lesion is removed, and the anvil of a No. 33 ILS stapler (Ethicon, EndoSurgery, Cincinnati, OH, USA) is placed into the lumen. The anvil is secured using a 2-0 purse-string suture. The anastomosis is then completed using the No. 33 ILS stapler (Ethicon, EndoSurgery, Cincinnati, OH, USA), and the bowel is returned to the abdomen.2
Appendectomy
Laparoscopic appendectomy is a safe procedure that does not increase perioperative morbidity or length of hospitalization.32 The appendix is identified, mobilized, and examined. Any adhesions from the appendix to surrounding structures must be lysed to provide adequate mobilization and exposure. The mesoappendix, including the appendical artery, is coagulated using bipolar forceps then cut using scissors or carbon dioxide (CO2) laser to skeletonize the appendix. A 35-m Endocutter stapler (Ethicon EndoSurgery, Cincinnati, OH, USA) is then placed perpendicular to the appendix at the base of the appendix. The stapler is fired, and the appendix is removed from the abdomen. The pelvis is filled with lactated Ringer’s solution and the appendiceal stump is submerged and inspected for hemostasis and air leak.2
Outcome—Pain
Multiple studies have reported good results with aggressive surgical management of intestinal endometriosis. Complete or significant pain relief with laparoscopic treatment of intestinal endometriosis is present in 75% to 91% of patients, with a significant reduction in dysmenorrhea, dyspareunia, pain with defecation, rectal bleeding, and non-menstrual pelvic pain.19,25,26,33
Outcome—Infertility
The role of endometriosis in infertility appears to be multifactorial. The mechanisms thought to be responsible for the decreased fecundity in patients with endometriosis are a reduction in oocyte quality, adverse peritoneal factors, fertilization defects, decreased embryo quality, and a microenvironment hostile to implantation.34 A recent study reported pregnancy rates in patients without tubal or male factors, who had failed in vitro fertilization (IVF) treatment. The patients who underwent complete laparoscopic treatment of endometriosis had significantly improved pregnancy rates following surgery (75% with surgery vs. 35% without surgery).35 Similarly, patients with a history of infertility and intestinal endometriosis, who underwent laparoscopic resection of bowel endometriosis, had significantly improved pregnancy rates following surgery (34.0% before surgery and 42.0% after surgery).31,36 These studies suggest that complete surgical treatment of endometriosis is critical in management of infertility patients.
Complication Rates
The complication rates for laparoscopic bowel resection are equivalent to laparotomy. A recent randomized controlled trial that compared laparoscopic versus open colectomy reported that the rates of intraoperative and postoperative complications were not significantly different.37 The rates of all (major and minor) complications associated with laparoscopic treatment of intestinal endometriosis are 5.0% to 15.5%.30,31,38 Bowel shaving has the lowest complication rate and disk excision and segmental resection have the highest.31
Conclusion
Although infiltrative bowel endometriosis is commonly noted in patients with endometriosis, it is rarely treated. The complete treatment of endometriosis is critical for symptomatic relief and improvement of fertility. All patients with endometriosis should be counseled regarding the possibility of intestinal endometriosis and risks and benefits of treatment. Thus, the operative approach should take into consideration the patient’s symptoms and fertility.
REFERENCES
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3. Te Linde RW, Thompson JD, Rock JA, et al. Te Linde's operative gynecology. 7th ed., Philadelphia: Lippincott. xxvii, p 1411, 1992.
4. Schenken RS, Malinak LR. Reoperation after initial treatment of endometriosis with conservative surgery. Am J Obstet Gynecol 1978;131(4):416-24.
5. Nezhat CC, Crowgey SSR, Garrison CCP. Surgical treatment of endometriosis via laser laparoscopy. Fertil Steril 1986;45(6):778-3.
6. Nezhat CCR, Nezhat FFR, Metzger DDA, et al. Adhesion reformation after reproductive surgery by videolaseroscopy. Fertil Steril 1990;53(6):1008-11.
7. Gutt CCN, Oniu TT, Schemmer PP, et al. Fewer adhesions induced by laparoscopic surgery? Surg Endosc 2004;18(6):898-906.
8. Nezhat C, Nezhat FR. Safe laser endoscopic excision or vaporization of peritoneal endometriosis. Fertil Steril 1989;52(1): 149-51.