Chapter 11.3 Ovarian Remnant
GENERAL PRINCIPLES
Definition
■ Ovarian remnant syndrome (ORS) is the condition of persistent, histologically confirmed ovarian cortical tissue, in patients who have undergone oophorectomy. Kaufmann reported ORS in 1962 and it was described in 1970 by Shemwell and Weed.
■ Follicular cyst, endometriosis, corpus luteum, serous cystadenoma, adenocarcinoma, clear cell carcinoma, and endometrioid carcinoma can exist in the ovarian remnant.
■ Risk factors leading to ORS include poor surgical technique, altered pelvic anatomy secondary to adhesions from previous surgery, endometriosis, pelvic inflammatory disease, ruptured appendix, and inflammatory bowel disease. Increased incidence of ORS after laparoscopic oophorectomy may be because of improper use of looped suture ligatures or the linear stapler as per small study done by Nezhat et al.7 Morcellation technique also contributed to increased risk by incomplete extraction of ovarian fragments resulting in implantation of ovarian tissue at different sites.
■ Growing awareness and advanced imaging technology led to an increased detection of these cases.
■ As there is a rise in laparoscopic ovarian surgeries, ovarian tissues can be implanted to port sites, anterior abdominal wall, and other abdominal organs leading to ORS.
■ Usually, remnant ovarian tissue is encased in the scar tissue from prior surgeries, endometriosis, or PID. Expansion of this tissue can lead to chronic pain which is one of the common presenting symptoms. Ovarian remnants can be found in 18% of patients with pelvic pain after oophorectomy.1 Other less common presenting symptoms are pelvic mass, back pain, variable bowel symptoms, and ureteric compression symptoms. Symptoms usually start 1 to 3 years after oophorectomy.
Differential Diagnosis
■ Residual ovary syndrome (secondary to retained ovary)
■ Supernumerary ovaries (the development of extra ovaries during embryogenesis through the arrest of migrating gonocytes that containovarian follicle tissue)
■ The most important concept in the differential diagnosis is to exclude other causes of chronic pelvic pain such as painful bladder syndrome, myofascial pelvic floor disorders, and irritable bowel syndrome.
Anatomic Considerations
■ The ovarian remnant can also be found adherent to the lateral pelvic wall (most common), vaginal vault, bladder, bowel wall, ureter, or uterosacral ligament.
Nonoperative Management
■ Suppression of ovarian tissue is the mainstay of treatment. This can be done by giving gonadotropin-releasing hormone analogues, danazol, birth control pills, depot medroxyprogesterone acetate injection, or etonogestrel implant. Levonorgestrel IUD can be considered if uterus is still present. None of these methods have been shown to be superior to other.
■ Irradiation has also been used but is least favorable because of the risk of damage to surrounding tissue.
IMAGING AND OTHER DIAGNOSTICS
■ Occasionally on pelvic examination we can palpate adnexal mass suggestive of ovarian remnant which needs to be confirmed by further imaging studies.
■ Transvaginal ultrasound is the main stay and cost-effective modality of imaging.
■ CT and MRI sometimes may help for preoperative preparation if the ovarian remnant is near to ureters, bladder, and bowel, or if ultrasound findings are inconclusive.
■ FSH and estradiol levels can also supplement the diagnosis along with the imaging studies. The level of FSH and estradiol should be in premenopausal range (FSH <40 mIU/mL and estradiol >30 pg/mL). If patient is on hormone replacement therapy, stop estrogen at least 10 days prior to testing these hormone levels.
■ Gonadotropin-releasing hormone analogue stimulation test is also helpful to diagnose the condition with an elevation of estradiol levels from day 1 to day 4 after receiving 3 days of leuprolide acetate (1 mg SC/d).
PREOPERATIVE PLANNING
■ Intraoperative laparoscopic ultrasonography8 may be helpful in detecting ovarian remnants especially in patients with distorted pelvic anatomy.
■ Administration of clomiphene citrate (50 to 100 mg twice daily for 10days) may help to make the ovarian tissue more prominent.
■ Preoperative pyelography may also define status of ureter and can predict surgical obstacles.
■ An informed consent should be obtained explaining all possible risks such as but not limited to infection, hemorrhage, injury to visceral organs, and major blood vessels. The consent should also include procedures such as resection of involved intra-abdominal organs with repair.
■ Cystoscopy is indicated if ovarian remnant is near to bladder or requiring extensive ureterolysis and dissection of bladder. Administration of methylene blue or indigo carmine or sodium fluorescein will help visualization of ureteral jets during intraoperative cystoscopy.
SURGICAL MANAGEMENT
■ Surgery is often mainstay of treatment because of side effects or inadequate response to medical therapy or if medical management is contraindicated or ovarian remnant is causing obstructive symptoms to urinary and gastrointestinal systems or any suspicion of ovarian cancer in the ovarian remnant.6
■ Laparotomy, laparoscopy, or robotic-assisted laparoscopic routes have been used.
■ Laparoscopy has been shown to be equally effective as laparotomy. There are advantages to laparoscopy as the magnification provided by the laparoscope through high-definition video technology, facilitates microdissection of tissue planes and easier identification of the remnant tissue. Increased intra-abdominal pressure helps decreasing the oozing of blood from the dissection and allows superior visualization of the retroperitoneal space.3 In patients with multiple previous surgeries, laparoscopic approach may be less traumatic.
■ Robotic-assisted surgery provides 3D view for adhesiolysis. Robotics also provides more magnification and flexibility of instruments but disadvantages include lack of tactile sensation and cost.
Positioning
■ Lithotomy position in Allen stirrups is preferable for both laparotomy and laparoscopic approach. Proper positioning is important to avoid any nerve injuries.
■ Arms should be tucked to patient’s side in military position, semi-pronated, with adequate padding placement around bony prominences especially the elbows and wrists. It is important to avoid too much of abduction at shoulders to prevent brachial plexus injury.
■ Adequate restraints should be placed around chest.
■ Buttocks should be well supported at the edge of the table. Hips should be flexed to not more than 90 degrees at thigh and abducted to not more than 45 degrees to avoid obturator, sciatic, and femoral nerve injury. Appropriate padding is needed on lateral side of knee to avoid compression injury of common peroneal nerve. Knee should be flexed to 90 degrees with slight adduction. Feet also need good support with padding.
■ Once the uterine manipulator is placed, the stirrups can be brought down to make thighs and abdomen at the same level, knees flexed to 90 degrees and thighs adducted in order to facilitate flexible movements of instrument.
■ Assistants should avoid leaning on to the suspended inferior extremities during the surgery.
■ Table should be kept flat for initial entry ports and then changed to Trendelenburg (less than 30 degrees) position for accessory ports.
■ Use anti-skid methods such as vacuum beanbag, gel pad, etc. can be used to decrease movement during Trendelenburg position.
Approach
■ Goal of surgical approach is high ligation of infundibulopelvic ligament after identifying and lateralizing the ureter by opening the retroperitoneal space and developing the para-rectal space.
■ Entry into the retroperitoneal space can be achieved by the following two techniques:
1. The peritoneum next to the round ligament is cut and the space entered.
2. The second is to start at the pelvic brim under the ovarian vessels. The peritoneum is grasped, incised and the space entered.
■ With either approach the ureter is identified and dissected from the pelvic brim to the level where the uterine artery crosses. Complete dissection of the ureter allows hemostasis to safely be achieved around the remnant dissection. The para-rectal space is identified with the ureter laterally, the rectum and mesorectum medially, and the pelvic floor at its base.
■ The visible ovarian remnant should be removed along with surrounding healthy tissue to avoid any recurrence.
■ In a study done by Fennimore et al.,2 ovarian stroma extends up to 1.4 cm into infundibulopelvic ligament. So, isolating infundibulopelvic ligament at least 2 cm from ovarian tissue to clamp and cut plays a key role in prevention.Ovarian Remnant Excision (Video 11.3)
Time out
■ Time out should be performed to ensure right procedure on right patient. Patient should be positioned as described above.
Preparation
■ The operating area needs to be prepped and draped in a sterile fashion. The drapes should be laparoscopic favorable with slits to have access to perineum. Insert a 16-French Foley catheter for bladder drainage. In the presence of uterus, placement of uterine manipulator will help to identify vaginal fornices and vesicocervical space. If uterus is absent, a ring forceps with a sponge at the tip can be inserted. Placing EEA sizer in rectum can help to distinguish the margins of the rectum as vast majority of these patients have distorted pelvic anatomy from extensive adhesions as a result of prior predisposing conditions. The EEA sizer, uterine manipulator, and vaginal sponge stick need to be covered with sterile glove on the external part to allow grasping with sterile gloves. The role of ureteral stents is debatable given reports of possible ureteral injury due to its rigidity. Advantage of using fiber-optic ureteral stents which can illuminate ureters during surgery is also questionable because the camera lights need to be dimmed. When bowel adhesions are anticipated, preoperative bowel preparation can be beneficial, although this is still a challenged concept.
Port placement
■ An orogastric tube should be inserted to decompress the stomach. The operating room table should be placed completely flat. Ensure that the electrosurgical pad has been placed on thigh. Local anesthetic such as 0.25% marcaine can be injected under the skin at port sites to give pain relief during and after surgery. For laparoscopic procedure, initial port is placed at the level of umbilicus, after insufflating with Veress needle, or directly with an optical trocar, or by an open (Hassan) technique. If the patient has a scar from prior midline abdominal incision, left upper quadrant entry at palmers point (3 cm below the rib cage at mid-clavicular line) is safe as the chance to encounter adhesions is minimal. Once intra-abdominal placement is confirmed by opening pressure less than 10 mm Hg, the peritoneal cavity is insufflated with CO2 to a pressure of less than 15 mm Hg. Patient is then placed in Trendelenburg position. Three extra 5- mm ports are then inserted under direct vision, two on the right and one on the left side. The distance between these ports should be 8 to 10 cm to avoid collision and to get maximum mobility of instruments. Lateral ports are placed under direct vision by observing the inferior epigastric vessels (lateral umbilicalligament) about 8 cm from the midline and 5 cm upwards from the symphysis pubis to avoid injury to epigastric vessels. For the best visualization, insufflate through assistant port and evacuate smoke through the camera port.
Adhesiolysis
■ Anticipate scar tissue and adhesions from prior surgeries. A survey of the peritoneal cavity is performed. Omental and bowel adhesions are taken down sharply and bipolar instruments are used for hemostasis. To clearly visualize ovarian remnants on the left side, the sigmoid colon needs to be mobilized medially from pelvic brim to cul-de-sac.
Locate ovarian remnant
■ In many cases, the remnant ovary is adherent to the lateral pelvic side wall as shown in Tech Figure 11.3.1.
Tech Figure 11.3.1. Ovarian remnant adherent to lateral pelvic sidewall.
Identify landmarks, ureters, and excise ovarian remnant
■ Identify the round ligament at its attachment to the deep inguinal ring and follow it medially. This is then coagulated, cut, and the retroperitoneal space entered (Tech Fig. 11.3.2). Extend the peritoneal incision cephalad parallel toinfundibulopelvic ligament, along external iliac artery to open up the retroperitoneal space (Tech Fig. 11.3.3). The ureter is then identified in the retroperitoneal space on the medial leaf of the broad ligament below the infundibulopelvic ligament (Tech Fig. 11.3.4A). However, if there has been prior endometriosis surgery the ureter may not be as easily visualized. If the ureter is not visualized clearly, dissect peritoneum more cephalad and laterally toward pelvic brim. Once ureter is identified, dissect and trace ureter caudad all the way to area where the uterine artery crosses the ureter or to the trigone of bladder if the tissue is seen adherent to the bladder. During dissection of the para-rectal space, always keep the ureter and internal iliac branches on the lateral side wall.
Avoid dissecting between the vessels. The infundibulopelvic ligament is skeletonized at least 2 cm from ovarian attachment, ideally cephalad to pelvic brim above the level of common iliac bifurcation. Create a window below infundibulopelvic ligament (Tech Fig. 11.3.4B) to coagulate and transect the ligament (Tech Fig. 11.3.4C). Try to remove adequate surrounding healthy peritoneal tissue margins to avoid any recurrence (Tech Fig. 11.3.5). Dissect ovarian remnant from ureter and surrounding vasculature before isolating from remaining surrounding tissue (Tech Fig. 11.3.6).
Tech Figure 11.3.2. Peritoneum next to round ligament and parallel to infundibulopelvic ligament.
Tech Figure 11.3.4. A: Ureter below infundibulopelvic ligament on medial leaf of peritoneum. B: Isolation of infundibulopelvic ligament. (continued)Tech Figure 11.3.4. (continued) C: Coagulation of infundibulopelvic ligament at the level of pelvic brim.
Tech Figure 11.3.5. Resection of ovarian remnant after separation from surrounding structures.
Tech Figure 11.3.6. Ovarian remnant in relation to ureter and ovarian vessels artery.
Removal of specimen
■ It is also important to remove the tissue in one piece especially in case of endometriosis as it can implant and give rise to recurrence. Consider removing the specimen in a tissue containment bag if there is a possibility of malignancy. Ovarian remnant tissue should be sent for histopathology for confirmation.
Achieve hemostasis
■ Attain adequate hemostasis either by bipolar energy for large vessels or monopolar energy for small bleeders. Irrigate and perform final check of the operating site for hemostasis after decreasing intra-abdominal pressure to 0 mm for 30 seconds.
Fascia and skin closure
■ Close fascia of all the ports more than 8 mm with 0 polyglactin suture. Skin incisions are closed with 4-0 polyglactin 910 or poliglecaprone suture.
Distinct case scenarios
■ Ovarian remnant can also be found adherent to vaginal vault, bladder, bowel wall, ureter, and uterosacral ligament. In this situation, pelvic spaces need to be opened up to clearly delineate structures and remove ovarian remnant without injury to surrounding organs.If attached to bowel
■ If ovarian remnant is attached to bowel and is invading muscularis layer, part of bowel wall has to be resected and the bowel wall can be sutured in one or two layers using 3-0 polyglactin suture. Air-tight closure is confirmed by insufflating air through a proctoscope under water. A laparoscopic bowel clamp should be used to occlude the sigmoid during insufflation. If attached to bladder or ureter
■ If ovarian remnant is deeply embedded in bladder, the vesicovaginal space needs to be dissected. A probe in the vagina will help delineate the limits of the bladder. The ureters should be dissected to the level of the trigone. Sometimes a segment of ureter will need to be removed requiring procedures such as ureteroneocystostomy. If attached to vaginal vault
■ When ovarian tissue is attached to vaginal vault, part of these tissues will be resected followed by repair.
Additional points
■ Patients who had unilateral oophorectomy, FSH values are of no significance and many times we do not consider them to have ORS which can lead to continued distress and pain.
■ Presence of large mass with elevated CA125 suggests malignant change, although normal CA125 cannot exclude the diagnosis. As the tumor is in retroperitoneal location, ascites seems to be a rare associated feature.
PEARLS AND PITFALLS
Prevention of port site implantation of ovarian tissue.
Use tissue containment bag to remove specimen without spillage of tissue and irrigation of port site with copious amount of normal saline.
Identifying ovarian remnant yet times can be challenging secondary to adhesions from prior surgeries and there is a higher possibility of ureteric injuries in the process of resection of ovarian remnant.
Always first identify round ligament and try to open para-rectal space to visualize and dissect ureter away from ovarian remnant.
Left-side ovarian remnant is common as infundibulopelvic ligament on this side is short and lacks clear visualization due to sigmoid colon.
Can be prevented by mobilizing sigmoid medially.
When severe periovarian adhesions are encountered blunt dissection can leave part of ovarian cortical tissue leading to recurrence.
Always perform sharp meticulous dissection.
POSTOPERATIVE CARE
■ Try to avoid parenteral pain medications. Consider oral NSAIDs and opioids. Resume regular diet. Remove the Foley as soon as possible unless you have created a cystotomy to excise the tissue. Discharge instructions for increase in abdominal pain, nausea, vomiting, and fever should be given. The patients should be followed up in 2 weeks.
OUTCOMES
■ Surgical treatment for ovarian remnant or ovarian retention syndrome is effective but is most effective in patients with no other pain-related diagnoses.
■ In a large study done at Mayo clinic by Magtibay et al.,5 out of 186 only one had recurrence of ORS and 90% had resolution of symptoms when above surgical principles were followed which were originally described by Webb in 1989.9
COMPLICATIONS
■ The incidence of injury to the bladder, ureter, and bowel at laparotomy for ovarian remnant is estimated to be 3% to 33%, with injuries to the ureter significantly greater by laparotomy than by laparoscopy.3
■ A recent study of ovarian remnant managed by laparoscopy by Nezhat et al.7 reported the rate of intraoperative complications at 5.8%, with fourintraoperative complications in 69 laparoscopies. However, there were no ureteral injuries. This series and others1,4 have demonstrated that the rate of complications with laparoscopic treatment of ovarian remnant is comparable to or lower than those reported in laparotomy.
■ In a comparative study done by Zapardiel et al.,10 between all surgical approaches laparoscopic route has less blood loss, lower postoperative complications, and shorter length of stay.
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