A disease that affects 10%-15% of women of reproductive age, endometriosis is quite prevalent. In 1990, investigators in Belgium first described deep endometriosis to highlight the diagnostic and therapeutic aspects of the disease (Fertil. Steril. 1990;53:978–83). In contrast to superficial disease, deep endometriosis constitutes the most severe form of endometriosis and includes nodules affecting the pouch of Douglas, retrocervical area, bladder, ureter, or the intestinal wall. Less frequently, the rectovaginal septum is involved (Arq. Gastroenterol. 2003;40:192–7). The treatment of bowel endometriosis is challenging, as it is a benign disease that may infiltrate the bowel, requiring a surgical treatment with increased risks.
Preoperative Diagnosis Using Imaging
The definitive diagnosis of deep endometriosis with bowel involvement is reached principally at the time of surgery. However, some clinical characteristics identified by history and physical examination, laboratory tests, and diagnostic imaging may raise suspicion for this form of endometriosis. A surgical approach is still recommended for confirmation and treatment.
Transvaginal ultrasonography (TVUS) still appears to be the superior imaging technique, providing the best cost-benefit ratio for cases of ovarian or deep endometriosis. The presence of a hypoechoic lesion located in the posterior pelvic compartment (see
When performed after complete bowel preparation and during the perimenstrual phase, TVUS carried out by a trained professional provides useful information for therapeutic management.
MRI can be performed to identify deep lesions. (See
Excretory urography or uro-MRI also is useful for evaluating whether the ureters are involved. When urinary tract involvement is suspected, one of these types of imaging should be performed to fully document the state of the urinary tract before surgery.
If we have doubts about the bowel involvement even after TVUS with bowel preparation, we recommend rectal echoendoscopy. (See
Rectal echoendoscopy also permits identification of the distance between the lesion and the rectal lumen, as well as identification of extrinsic compression and lesions of the rectal submucosa. This information can be critical in the preoperative planning of the type of surgery required and the need to have the help of a colorectal surgeon. The chart on page 19 shows the algorithm for preoperative work-up depending on clinical and TVUS findings.
Treatment: Clinical or Surgical?
Medical treatment of deep endometriosis, as opposed to surgical treatment, remains controversial. Dr. Luigi Fedele and his associates in Italy reported a substantial improvement in pain during 6 months of treatment with GnRH analogs (Am. J. Obstet. Gynecol. 2000;183:1462–7). Similar improvements in pain were also observed by our group with both an intrauterine device medicated with levonorgestrel and with a GnRH analog (Hum. Reprod. 2005;20:1993–8). In Dr. Fedele's study, however, an early relapse occurred following discontinuation of treatment. In addition, the endometriotic lesions underwent a discrete but significant reduction in size as detected by TVUS during treatment, but returned to their original size 6 months after suspension of GnRH treatment.
In cases of intractable pain (measured by scores greater than 7 in the visual analog scale) and/or two previously failed IVF cycles, surgical treatment is required. Access for surgical treatment may be by laparotomy or laparoscopy, depending on the surgeon's experience; however, laparoscopy can provide a better visualization of the lesions, allowing a more precise excision.
Surgical Preparation and Technique
Whenever there is clinical suspicion of deep endometriosis, adequate presurgical bowel preparation is indicated. We recommend the use of 3–4 liters of an oral solution of polyethylene glycol (PEG) the day before surgery, followed by one or two Fleet enemas or a mannitol preparation.
Administration of antibiotics should be carried out during anesthetic induction, preferably using a second-generation cephalosporin (2 g intravenously).
When the preoperative rectal ultrasound permits identification of the depth of the lesion, this information can be used to define the type of surgery that will be performed. In the case of unifocal lesions less than 3 cm in size (major diameter) and affecting the serous and external muscular layers of the rectum or sigmoid, resection of the nodule alone may be indicated. This procedure may be done manually or with the help of a circular stapler. (
Our technique approached laparoscopically is as follows:
▸ The lesion on the rectosigmoid is delineated, and adhesions are lysed from contiguous organs such as adnexae, the uterus, or other loops of bowel. We prefer to use scissors or a hook.
▸ To resect the lesion manually (without the use of a disposable stapler), the endometriotic nodule is excised, taking care not to leave any residual disease behind. The defect is then repaired in a double-layer fashion. On the mucosal layer, 3–0 absorbable suture is used in a running and transverse manner to avoid bowel constriction. On the seromuscular layer, 3–0 permanent suture is used in a running manner to imbricate over the first layer.