Chapter 11.2 Oophorectomy. Operative Techniques

 Chapter 11.2 Oophorectomy

GENERAL PRINCIPLES

Definition

Oophorectomy is the surgical removal of the adnexa or a portion of the adnexa. Typically this will involve removing the entire ovary and fallopian tube (adnexa) along with its vascular supply; however, in some conditions removing the fallopian tube alone, the ovary, or a portion of the ovary itself may be indicated. This chapter will focus upon removal of the entire adnexa recognizing that the techniques described can be applied to remove any portion of the adnexa.

Differential Diagnosis

■ Prophylactic risk reducing surgery for breast, ovarian, or other genetic condition

■ Benign adnexal tumors (serous or mucinous cystadenomas, teratomas, adenofibromas, among others)

■ Endometriosis or endometriomas

■ Tubo-ovarian abscess

■ Borderline ovarian tumors

■ Malignant ovarian tumors (epithelial, germ cell, or stromal tumors)

Anatomic Considerations

The steps of surgical removal of the ovary will be informed by the anatomy. Although it seems obvious, the anatomic relationships of the ovary to the uterus, ureter, iliac vessels, and bowel will to one degree or another become altered in pathologic situations. The degree of aberration will vary from case to case and across pathologic conditions; however, the basic surgical approach needs not vary. A detailed understanding of the normal anatomy of the adnexa and the surrounding structures is essential and will inform the surgeon on how to best approach the particular pathology at hand. The first step in any surgery is to restore the anatomy to normal. This can be especially important when preforming difficult surgery to remove the adnexa. Once adhesions are lysed and normal anatomic relationships re-established, the level of complexity has been reduced allowing the surgeon to more easily remove the ovary.The ovary is a retroperitoneal organ that resides in the pelvis. It is attached by a vascular pedicle to the uterine cornua (Fig. 11.2.1). Its arterial blood supply, however, originates off the aorta just distal to the renal vessels. The venous return runs adjacent to and inferior to the gonadal artery. These veins can become engorged in some pathologic conditions and often have multiple tributaries. The right gonadal vein empties into the vena cava directly; however, the left ovarian vein empties into the left renal vein (Fig. 11.2.2).

The gonadal vessels travel toward the pelvis parallel to and adjacent to the ureter. Just like the ureter, the gonadal vessels cross the pelvic brim at the level of the bifurcation of the iliac vessels. The gonadal vessels are lateral and superior to the ureter at the pelvic brim. This relationship is difficult to appreciate unless the retroperitoneum overlying the gonadal vessels is opened (Fig. 11.2.3). The gonadal vessels insert into the ovary and, after passing by the ovary anastomose into the utero-ovarian pedicle at the cornua. The uteroovarian pedicle contributes blood supply to the ovary and fallopian tube along its course. Again, while it may be difficult to appreciate, a layer of peritoneum covers the ovary and its blood supply, tube, and uterus.1

The concept of “restoring anatomy to normal” is predicated upon a complete understanding of these anatomic relationships. Expert pelvic surgeons understand and use the relationship between the gynecologic organs, the rectum, and the genital urinary system to inform their surgical decisions.

The most important anatomic concept to recognize is that the bladder, ureters, and rectum, as well as the ovaries, tubes, and uterus are NOT located in the pelvis but in the retroperitoneum (Fig. 11.2.4). The rectosigmoid and ileum are the only true pelvic organs once we understand this anatomic relationship. In reality, for many operations this distinction is irrelevant. However, for complex ovarian surgery, it is critical to perform the operation quickly, safely, and with assurance that there has been no unintended injuries.

Figure 11.2.1. Utero-ovarian pedicle. The adnexa attach at the uterine cornua and share a rich vascular anastomosis with the uterine blood supply.

Figure 11.2.3. Pelvic sidewall. The peritoneum overlying the right pelvic sidewall is incised demonstrating the ureter, external iliac vessels, and the gonadal vessels (deviated laterally).

While this is a subtle distinction, it is an important one. When tackling a complex pelvic surgery with multiple adhesions and perhaps a pelvic mass adherent to the pelvic sidewall, recognizing this relationship will enable the surgeon to proceed judiciously. Lysing adhesions becomes easier when one recognizes that adhesions between loops of small bowel and to the rectosigmoid are inherently different than those to the adnexa or uterus. In fact, since there are no normal attachments of the ovaries to the true pelvic organs, these can be easily managed by following the course of bowel loops and sharply lysing adhesions free from the ovarian tumor or uterus. A systemic approach is often the best, beginning where the anatomy is normal and proceeding toward areas of complexity. With this approach, the surgeon continues until the anatomy becomes confusing, at which point the focus changes to another area where the adhesions are less complex. With this approach, areas of adhesions that were initially difficult to lyse successfully, can more easily be managed (see Video 11.2.1, Part A). Careful dissection is important with attention to hemostasis as the planes between loops of bowel and the adnexa can be easily masked by blood. Sharp dissection offers some advantages over cautery because when the surgeon is in the correct anatomic plane there is little if any bleeding. In addition, there is no concern of thermal spread from cautery. Energy devices, such as harmonic or ligasure seal peritoneal edges together, are generally counterproductive when tackling adhesions.

Figure 11.2.2. Ovarian vasculature. The ovarian arteries originate from the aorta beneath the renal vessels. Venous return on the right empties directly in the vena cava and on the left into the left renal vein.

Nonoperative Management

Nonoperative management of an adnexal mass is appropriate in certain situations and should be individualized based upon the patient. While conservative management of adnexal masses can occupy an entire chapter, a few guiding principles are worth discussing. In general, symptomatic or complex lesions should be managed surgically. In addition, an adnexal mass of 8 cm or larger is unlikely to resolve spontaneously and is at higher risk of torsion, making observation in these situations of questionable benefit. The risk of surgical intervention to manage the patient’s symptoms and assess for malignancy must always be balanced by medical comorbidities, desire for future fertility, and to some extent loss of hormonal function. Repeat imaging at 6 weeks in premenopausal woman is reasonable when the adnexal mass is thought to be a hemorrhagic or functional cyst. If this lesion is still present at that point, it is less likely to resolve and surgical intervention is generally warranted.

IMAGING AND OTHER DIAGNOSTICS

■ Imaging plays an increasingly important role of assessment of ovarian tumors. The most common preoperative imaging is ultrasound assessment. Not only is this noninvasive, inexpensive, and universally available, it does a reasonably good job of characterizing features of the ovarian mass. Simple cystic masses are almost always benign regardless of the size. Therole of surgical intervention will vary based upon the patient; however, simple cystic masses that are 8 cm or greater or those with solid components are unlikely to resolve spontaneously. In most cases these should be removed. Based on ultrasound assessment, “complex” ovarian masses will encompass a broad range of tumors from a simple cystic lesion with septation(s) to a largely solid lesion with multiple small cysts. Many benign tumors can appear fairly complex on ultrasound such as endometriomas, adenofibromas, and mucinous cystadenomas. Additional imaging, such as MRI, rarely adds much to distinguish between these entities and cannot rule out malignancy. CT scans may be helpful in some situations. In reality, they do not offer any additional information about the adnexal mass; however, they can identify other high-risk features that the surgeon may need to be aware, such as hydronephrosis, ascites, adenopathy, omental implants, and other findings suggestive of ovarian malignancy.2,3

Figure 11.2.4. Course of ovarian vessels. The ovarian artery and veins run in the retroperitoneum adjacent to the ureter and cross the pelvic brim prior to supplying the ovary and anastomosing with the utero-ovarian pedicle.

■ Tumor markers are used frequently in the preoperative assessment of a pelvic mass. CA125, CEA, and CA19-9 are commonly ordered and may help appropriately triage patients to an oncologist. It is fairly common to see elevation of CA125 and to a lesser extent CEA and CA19-9 in patients with benign adnexal masses; however, these are rarely more than one or two standard deviations above the normal range. The use of a panel of tumormarkers, such as ROMA, may increase specificity. A 40-year-old woman with a complex mass, history of worsening pain over several years, and a CA125 of 80 more likely has endometriosis than an ovarian malignancy.

Nonetheless, care should be exercised in these situations. A management plan ought to be addressed preoperatively with the patient if malignancy is identified at the time of surgery. In certain situations, immediate assessment and management with gynecologic oncology is feasible. In situations where gynecologic oncology is not readily available and malignancy is identified at surgery, the best approach is often to make a diagnosis (remove the ovary or simply obtain a biopsy) and close the patient deferring definitive management to a later time. Studies have shown that the quality of surgery in women with ovarian cancer directly impacts survival. Patients managed by general surgeons, urologist, and gynecologist working in concert to stage or debulk ovarian tumors do not do as well as those managed by gynecologic oncology.4

PREOPERATIVE PLANNING

■ Pathology that involves the adnexa will vary from relatively simple ovarian cystic lesions to complex masses that are densely adherent to the colon or pelvic sidewall. Obliteration of the cul-de-sac can present a difficult challenge to overcome when removing a pelvic mass. Often, while the surgeon may suspect they will be facing a complex case the question is how best to properly prepare. In some circumstances, it may be best to refer to patient to a specialist, especially if malignancy is a concern.

■ Careful review of the patient’s medical and surgical history is as important as preoperative imaging and tumor markers and the best place to start the preoperative assessment. While the differential diagnosis of an adnexal mass is broad, reviewing the patient’s history can often time narrow down the possibilities. A reasonable approach is to first determine if the mass is likely benign or malignant. Age alone can be a useful piece of information, as epithelial ovarian cancer is quite rare in women younger than 40 without a personal or suspicious family history of malignancy regardless of tumor markers or complexity reported on sonography. Further, masses in prepubertal or adolescent patients carry a higher risk of malignancy and often should be approached cautiously. Menstrual history is informative as well. Adnexal masses such as granulosa cell tumors, adenofibromas, or Sertoli–Leydig tumors among others may produce hormones that can alter menstrual function as well as produce symptoms such as breast tenderness, deepening voice, or male pattern hair distribution. A history of pain is another important characteristic to investigate. Acute pain may indicate torsion that may not only impact the urgency of operative intervention, but may alter sonographic appearance of the tumor leading one to be far moreconcerned of malignancy. Chronic pain in association with a complex mass may be indicative of an endometrioma and advanced endometriosis.

■ The preoperative impression and assessment will determine the appropriate surgery best suited for the patient. This along with the surgeon’s skill set will ultimately influence the surgical approach. Regardless of whether one uses a minimally invasive or an open approach, the steps in the surgical removal of the ovary should be the similar. The remainder of the chapter will focus on surgical approaches to removal of ovarian tumors. In general, there are three approaches to removal of the ovary: transperitoneal, retroperitoneal, and retrograde resection. Each has its benefits and certain approaches may be better suited to certain pathologic or anatomic conditions identified in the operating room. An expert pelvic surgeon should have all three approaches in their armamentarium.

SURGICAL MANAGEMENT

■ The surgical removal of the adnexa will vary depending upon the nature of the pathology, patient characteristics, and the scope of other procedures that are being performed at the time of surgery. The indications for surgery will vary as will the complexity of the operation. When the adnexa are removed for prophylaxis such as in woman at high risk for ovarian cancer, the anatomy is generally normal and the operation is often straightforward.

In women with benign adnexal masses, the surgery can be quite a bit more challenging depending upon the pathology found in the operating room. Some of the most complicated and difficult procedures are in women with advanced endometriosis or cancer. Prior surgery, diverticular disease or other conditions may lead to adhesive disease compounding the difficulty of oophorectomy. The surgeon’s preoperative assessment is essential to plan the best surgical approach and to council the patient preoperatively regarding the extent of dissection and possible complications. After factoring all these variables, the surgeon then can select the best surgical approach.

■ The surgical approach—open, laparoscopic, or robotic—is best decided upon after consideration of the aforementioned factors balanced by the surgeon’s skill set. Minimally invasive surgery is generally associated with less postoperative pain, quicker recovery and return to baseline functional status, lower EBL, and lower infection rates. Unfortunately, in some instances, there may be higher complication rates such as unintended bowel or GU injury especially when tackling a challenging case. Resulting complications are as likely influenced by the surgeon’s comfort and skill level with laparoscopy or robotics as they are with the pathology identified at the time of surgery. That being said, a good surgeon is aware of their limitations and should choose an approach that will best serve their patient.With this in mind, it may be equally reasonable to approach the same problem either open or minimally invasively depending upon the comfort level of the surgeon and the anticipated complexity of the case. Even so, the surgeon’s preoperative assessment may change at the time of surgery.

As the intraoperative findings dictate, the surgical approach may by necessity change from minimally invasive to open or from robotic to laparoscopic in some cases.5

Intraoperative Assessment

■ Regardless of the surgical approach, the first step prior to removing the

adnexa is to evaluate the abdomen and pelvis. This can generally be done

quickly either laparoscopically or during exploratory surgery. A quick

survey will identify any unexpected pathology such as adhesions that may

impact the scope of surgery. Only at that point should the surgical plan be

decided and the operation begins. Should adhesions be encountered, these

should be managed first in order to restore anatomy to normal. Once

completed, removing the adnexal mass should be relatively uncomplicated.

■ In certain situations, adhesions may be dense or may completely obliterate the normal anatomic relationships such as with advanced endometriosis or a pelvic malignancy. Often, as in these two diseases, the peritoneum is involved with the disease process and restoring these planes is not possible. It is important to note that these processes generally do not invade through the peritoneum. In these circumstances, the knowledge that there is a layer of peritoneum between the ovaries and the rectosigmoid, for instance, can be used to the surgeon’s advantage. Often the best approach is to enter the retroperitoneum laterally and cephalad to the pelvis. This offers several advantages. First, the surgery begins in an area without distorted anatomy. The blood supply to the ovary, which originates off the aorta just below the renal vessels, can be identified and isolated anywhere along its course. Many times, this is most easily accomplished at the pelvic brim or, if the pathology dictates, in the abdomen itself. The second advantage is the surgeon can now directly visualize the ureter and iliac vessels lessening the likelihood of injury (Fig. 11.2.5). The peritoneum can generally easily be separated from these retroperitoneal structures even in situations where dense inseparable adhesions are present in the pelvis proper. This approach, opening the peritoneum, entering the retroperitoneum, and isolating the IP, allows mobilization of the ovarian mass from its lateral attachments. In certain cases, the ureter may be in harms way and at this point can be isolated with a vessel loop (Fig. 11.2.6). The ureter can be dissected free from the peritoneum completely to the insertion into the bladder separating it from the ovarian mass when necessary. Securing the vascular supply of the ovary early in the case also has the advantage of decreasing blood loss.Blood loss in addition to possibly compromising the patient’s health will tend to obscure the surgical field complicating an already difficult dissection.

Figure 11.2.5. Retroperitoneum. The right pelvic sidewall was opened demonstrating the ureter crossing the common iliac artery. The utero-ovarian pedicle was divided and the ovary and gonadal vessels reflected cephalad.

Figure 11.2.6. Ureterolysis. Once the retroperitoneum is developed, the ureter can be more easily dissected after placing a vessel loop and placing it on gentle traction.

■ Once the mass is mobilized medially, the surgeon can then focus upon ligating the remaining blood supply—the utero-ovarian pedicle, unless the uterus is being removed with the ovary itself. This pedicle has many venous channels and can be easily torn, leading to retroperitoneal hematomas. Securing this pedicle can be done in any variety of ways—suture ligation, energy such as bipolar or harmonic or with a vascular stapling device. Each method has its own advantages, cost, ease, speed, or vascular security. The manner in which this pedicle is secured is surgeon- and situation-dependent. After isolating this pedicle and ligating it, most complex adherent masses can be removed with gentle traction (see Video 11.2.1). Only in the situation of advanced endometriosis, ovarian malignancy, or diverticular abscess, resection of the rectosigmoid colon along with some or all of the pelvic peritoneum may be required. The major advantage to a radicalresection with en bloc rectosigmoid resection is that all the peritoneum in the pelvis can be removed with the disease encapsulated (Fig. 11.2.7).

Figure 11.2.7. Radical en bloc resection. Radical resection is often the best approach to extirpate the pelvis of metastatic ovarian cancer.

Positioning

■ Patient positioning for complex pelvic surgery should be done in low lithotomy if at all possible. Placing the patient in this manner will allow easy access to the bladder, vagina, and rectum without repositioning. We recommend prepping the perineum and vagina in all cases and placing the Foley and uterine manipulator (if applicable) after the patient has been prepped and draped.

Approach

■ Transperitoneal approach: the most common approach to removing the adnexa, especially for simple benign lesions

■ Retroperitoneal approach: an anatomic dissection that allows for safe resection of complex, adherent, and malignant tumors

■ Retrograde resection: a relatively uncommon approach that is helpful in situations where the ureter cannot be identified at the pelvic brim or when taking the gonadal vessels.Procedures and Techniques

Transperitoneal resection

The most straightforward approach is a transperitoneal resection. This is the most commonly preformed approach for removing a benign ovarian mass. This approach involves lifting the adnexa off the pelvic sidewall and placing its blood supply on tension. The ureter is identified through the peritoneum to assure it will not be injured. The ovarian vessels are ligated, most often, through the peritoneum.

Typically an energy device, such as ligasure, is used to seal the gonadal vessels during MIS and a suture ligature is most often used when done during laparotomy. The transperitoneal approach has several advantages, ease and speed among them. This technique works well when dealing with benign ovaries, simple cystic, or even solid masses that are not adherent to the ovarian fossa or pelvic sidewall. The major disadvantage to this technique is vascular sealing integrity. When elevating the ovarian vessels off the pelvic sidewall and using an energy device, the surgeon transects the vessels at an oblique angle resulting in a larger vessel to be sealed.

In comparison, by opening the peritoneum and isolating the vessel, the vessels can be ligated perpendicular to their axis resulting in a smaller area and more secure vascular pedicle. This is an important distinction. A compromise in the vascular integrity of the gonadal vessels can lead to a retroperitoneal bleed requiring transfusion and occasionally reoperation (Tech Fig. 11.2.1).

Tech Figure 11.2.1. The peritoneum. The peritoneum covers the aorta, IVC, as well as the ureters and gonadal vessels. It covers the pelvic viscera including the rectum, uterus, adnexa, and bladder.

Retroperitoneal resectionFor more complex operations, a retroperitoneal approach is often the preferred surgical approach. While this is inherently more involved, it will often save time by identifying critical structures (ureter, iliac vessels) and avoiding unintended injury. By entering the peritoneum, this approach enables the surgeon to proceed with the anatomic dissection in the retroperitoneum on the opposite side of the ovarian pathology. Utilizing this technique, not only are the ureters and iliac vessels lateral to the dissection, but the adherent ovarian mass and peritoneum are now lifted off these critical structures as well. After securing the blood supply, the ovary can be removed, even if densely adherent to pelvic structure with relative ease and security in knowing a catastrophic vascular or ureteral injury has been avoided.

This technique relies upon the surgeon being comfortable operating in the retroperitoneum. To begin the operation, after lysing any adhesions and mobilizing the bowel out of harms way, the retroperitoneum is opened. This is best done lateral to the pelvic sidewall along the psoas muscle as there are no critical structures to inadvertently injure. On the left, it is most often necessary to mobilize the rectosigmoid from its peritoneal attachments to develop this space. While not always necessary, it is often helpful to mobilize both the left and right colon along Toldt’s line. This facilitates identifying the gonadal blood supply and ureter as they cross the pelvic brim. By entering the retroperitoneum cephalad of any pelvic pathology, it is easier to identify these structures and dissect down toward the area of abnormality. Once the gonadal vessels are identified, they can be isolated and ligated. Again, this is typically done with suture in an open case and with an energy device when approached minimally invasively. Nonetheless, the principles are the same. The vessels should be isolated and transected perpendicular to their long axis yielding a secure vascular pedicle. Suture ligature is unnecessary and perhaps counterproductive as the IP can have extensive and tortuous venous channels that can be injured leading to retroperitoneal hematoma. After securing the vascular pedicle, the ovarian mass can then be mobilized from its pelvic attachments with less blood loss and the knowledge that the ureter has not been injured at that point (see Video 11.2.1).

In certain situations, the ureter is densely adherent to pelvic mass. In these circumstances, it is prudent to identify the ureter at the pelvic brim where it crosses the bifurcation of the external and internal iliac vessels (Tech Fig. 11.2.2). This is almost always the best place to identify the ureter because this anatomic relationship does not alter despite extensive pelvic and abdominal diseases. Once the ureter is identified, it should be carefully dissected from the peritoneum leaving its adventitia intact and a vessel loop can be placed around it. With gentle traction, the ureter can be followed safely along its course and the ovarian mass dissected free.

Tech Figure 11.2.2. The ureter. The ureter runs parallel to the ovarian vessels. It crosses the pelvic brim at the bifurcation of the common iliac artery. This is a convenient place to identify it and follow it into the pelvis.

This approach will generally then allows the surgeon to elevate the mass off the sidewall with the IP secure and ureter free of injury. The only remaining vascular pedicle is the attachment to the uterus. This can be ligated when leaving the uterus in situ, or can be left intact if the patient is undergoing hysterectomy. It is worth mentioning that this approach can be performed during MIS or laparotomy with slight variation in technique.

Retrograde resection

Perhaps the least common approach to removing an ovarian tumor is a retrograde dissection. This is similar to the retroperitoneal resection discussed above but essentially done in reverse. This may be helpful in situations where the surgeon cannot identify the ureter despite developing the retroperitoneal spaces. In such a case, inadvertent ligation of the ureter may occur when securing the gonadal vessels. This situation is not infrequently encountered in endometriosis or in patients with retroperitoneal fibrosis. Rather than proceeding with ligation of the IP, the surgeon can instead work from the uterine fundus in a retrograde fashion. The first step is to extend the retroperitoneal incision along the psoas muscle and external iliac vessel toward the round ligament. If the retroperitoneum is difficult to develop cephalad or the pathology is obscuring visualization of the ureter, the surgeon may have better luck moving inferiorly. Starting just cephalad to the round ligament and with traction on the uterine cornu medially, the retroperitoneum can often be entered. Dissection medially to develop the pararectal spaces is helpful toisolate the utero-ovarian pedicle and drop the ureter inferiorly. The utero-ovarian pedicle can be secured at this point allowing the ovarian mass to be mobilized cephalad in a retrograde fashion. With gentle traction and either cautery or sharp dissection, the mass can be lifted out of the pelvis, isolating the gonadal vessels.

Once the ovarian pedicle can be seen at the pelvic brim, it can be safely ligated. With this technique, the ureter should remain free of harm despite the fact that it has not been previously identified. It is always good practice when using a retrograde approach once the mass has been removed to identify the ureter and follow it along the course of dissection to confirm that it has not been injured. In summary, the approach to removing the adnexa is dependent upon a number of patient-related factors along with the pathology at hand. These will dictate the most judicious approach to utilize transperitoneal, retroperitoneal, or a retrograde resection. Each approach has its advantages as discussed; however, expert pelvic surgeons should be familiar with each approach.

PEARLS AND PITFALLS

Restore anatomy to normal

Prior to beginning the planned surgical procedure, restore anatomy to normal by lysing all adhesions and identifying normal anatomic landmarks.

Develop the retroperitoneal spaces

Opening the retroperitoneum allows quick and accurate identification of the major blood vessels and ureter to assure they are out of harms way prior to surgical resection of the adnexa.

Mobilizing the rectosigmoid colon

This can be a helpful maneuver when dealing with left-sided adnexal masses.

Use two hands when preforming complex laparoscopy

The surgeon is better able to perform complex surgery using their two hands than trying to communicate with an assistant. Adding another trochar often can make a difficult case substantially easier.

POSTOPERATIVE CARE

■ Postoperative care following oophorectomy depends more upon the surgical approach—open or MIS than on the operation itself. In general, when done robotically or laparoscopically removal of the adnexa is an outpatient procedure. In circumstances where laparotomy is required, we generally recommend rapid early feeding, ambulation, and minimization of IVFs.

COMPLICATIONS

■ The most dreaded complication of oophorectomy is unintentional ureteral or bowel injury. The techniques described above will help minimize these complications; however, it should be recognized that in some cases these injuries are unavoidable given the pathology at hand. The key to avoiding morbidity is to recognize these injuries intraoperatively. Bowel or ureteral injury is relatively inconsequential when identified and properly repaired at the time of surgery. Delayed identification can be life threatening in addition to the need for emergent or repeat operations to address the complication. Proper surgical technique, a solid understanding of abdominal and pelvic anatomy, will allow a surgeon do perform complex cases with few injuries.