R. Stanford Williams
INTRODUCTION
Although hysteroscopy has been described since the early 1800s, widespread use by practicing gynecologists did not occur until the 1980s. With improvements in optics, video systems, and distension media, there has been an increased acceptance of hysteroscopy as the gold standard in the evaluation of the uterine cavity and treatment of intracavitary pathology.
Hysteroscopy is used most commonly for evaluation of abnormal uterine bleeding, but it also is used frequently for evaluation of the endometrial cavity in patients with recurrent pregnancy loss and infertility. Many studies have shown that blind dilation and curettage may miss up to 60% of endometrial pathology, such as endometrial polyps and submucous leiomyoma, although with increasing expertise in ultrasonographic techniques such as the saline sonohysterogram, endometrial pathology often can be suspected prior to performing definitive operative hysteroscopy. Alternatively, many practitioners perform office hysteroscopy with small-diameter hysteroscopes, which do not require significant dilation of the cervix, can provide direct visualization of the endometrial cavity, and facilitate a directed biopsy of suspected endometrial lesions.
Operative hysteroscopy requires larger diameter instrumentation and is best performed under anesthesia in the outpatient operating room because of the need for significant cervical dilation and more extensive instrumentation. Hysteroscopic surgery allows a variety of intrauterine surgical procedures such as myomectomy, polypectomy, resection of a uterine septum, endometrial ablation, correction of intrauterine synechiae, and cannulation of proximal tubal occlusion.
INSTRUMENTATION
Hysteroscopy can be used both as a primary diagnostic tool and as a more definitive operative technique. Diagnostic hysteroscopy can be performed either in an office setting or in the outpatient operating room and requires only small 3.6-mm to 5-mm hysteroscopes. These hysteroscopes may be either flexible or rigid. A small channel often is provided for a small biopsy instrument, but these are rather delicate, and significant surgical procedures will require larger hysteroscopes.
The flexible hysteroscope is used often for office hysteroscopy because it can be inserted through a narrow cervical os and can negotiate the cervical canal, using a deflecting lever to guide the instrument. The flexible hysteroscope is available in two diameters, 3.6 mm and 4.9 mm, both with a zero-degree optical view. The larger diameter endoscope also provides a 2.2-mm diameter instrument channel, which allows for directed biopsies of endometrial pathology. The larger instrument provides better optics than the smaller flexible hysteroscope but is still somewhat inferior optically to a 4-mm rigid scope.
Most small diagnostic hysteroscopes have only a single channel for installation of a distending medium. In an office setting, many physicians employ CO2 as the distension medium, necessitating the use of a hysteroscopic insufflator to control intrauterine pressure. If blood or mucus is present within the endometrial cavity, a liquid medium will be required. If a low-viscosity liquid distension medium is used, then a continuous flow sheath, which allows for the continuous simultaneous inflow and outflow of the medium, thus flushing any blood or mucus from the cavity, will give the optimal view.
Rigid hysteroscopes are available with 0-, 12-, 15-, 30- and 70-degree optical view telescopes. Thirty-degree scopes are used primarily for diagnostic procedures in order to see easily the entire endometrial cavity by rotating the telescope 360 degrees. Operative procedures most commonly require the 12- or 15-degree telescopes, so that the operational component of the instrumentation can be visualized fully.
The operative hysteroscope uses a 4-mm rigid telescope within a 7- to 8-mm operative sheath, which can be configured to either provide a port for the insertion of accessory instruments (scissors, biopsy forceps, catheters) or use a resectoscope with a working element for resectoscope electrodes. Older models of operative hysteroscopes included only a single channel for installation of distension medium. Adequate egress of fluid usually is not possible with these hysteroscopes, because the only available exits are the fallopian tubes or around the hysteroscope through a patulous or over-dilated cervix. Use of these single-channel hysteroscopes should be limited to high-viscosity distension media. Most commonly, operative hysteroscopy is performed with a continuous flow sheath allowing for input of the distension medium through a middle channel and egress of the medium through an outer evacuation channel. This provides for constant washing of the uterine cavity, removing blood and debris and allowing the use of a low-viscosity distension medium.
Infusion of low-viscosity fluids can be accomplished either by the force of gravity or with infusion pumps. Suction tubing attached to the outflow port can be directed to wall suction or allowed to drain by gravity. Low-viscosity–fluid pumps have been designed to operate in pressure ranges of 0 to 80 mm Hg. They can deliver fluid at a rate necessary to maintain a preset pressure with a maximum flow rate of 300 mL/minute, although the upper limit of flow through the outflow ports for most hysteroscopes is 250 mL/minute. Outflow usually is adjusted to be significantly lower than the maximum to allow adequate visualization free from blood and debris, maintain adequate uterine distension, and minimize the amount of fluid needed to complete the procedure.
Alternatively, inflow of the distension medium can be controlled by gravity. The height of the bag of infusion medium above the patient controls the maximum intrauterine pressure. Every 1 foot of height above the patient that the bag of distension medium is placed will deliver approximately 25 mm Hg of pressure to the endometrial cavity. This system is then regulated by the amount of outflow, to maximize visualization while maintaining adequate uterine pressure. Because pressure of inflow is constant, changes in intrauterine pressure, and thus distension, are affected by alterations of the rate of the outflow. Use of standard suction containers to collect the outflow will make fluid measurement and calculation of any fluid deficit straightforward.
Modern operative hysteroscopy requires a video camera and video monitor for adequate operative visualization. A halogen or xenon light source providing 150 to 300 watts of incandescent light is used and attached to the hysteroscope by a fiber optic light cable. The light cable should be inspected frequently to ensure that a significant number of the internal fibers have not broken and that the light cable is capable of delivering an adequate amount of light through the hysteroscope. Most chip cameras have the capability to adjust gain and can be integrated with the light source for automatic light balance.
For documentation of findings and recording of procedures, video capture units may be used. Most commonly, VCRs are used to videotape pertinent portions of the procedure. Also available are video capture units for taking still pictures or storing digital images on a computer hard disk or CD.
Energy for operative hysteroscopy can be delivered either with the Nd:YAG laser or with electrosurgical generators delivering either unipolar or bipolar energy. Other lasers, such as the CO2 laser, are not used in hysteroscopy because of their failure to penetrate fluid and because of the generation of smoke if CO2 is used as the distension medium. The Nd:YAG laser can be delivered through a flexible quartz fiber passed through the instrument channel of the operating hysteroscope, and its wavelength penetrates through the liquid distension medium used in hysteroscopy. The extent of tissue necrosis can be up to a depth of 4 to 5 mm. Varying the distance of the fiber tip and incident angle can regulate the extent of thermal damage. It is rendered ineffective at distances greater than 2 cm or as the incident angle deviates more than 90 degrees. This laser is used often to perform endometrial ablation, using power outputs of 50 watts by dragging the fiber over endometrial surfaces.
Electrosurgery through a standard resectoscope usually utilizes a monopolar technique, with the electrical probe serving as the source electrode and the return plate on the patient as the return electrode. The resectoscope can be used with either cut or coagulation output settings on the electrosurgical generator, or a blend of the two. When used in the cutting mode a high-frequency sine wave is delivered, which creates extremely high current density, instantly superheating cellular water to vaporization, causing cellular architecture to explode, resulting in tissue cutting. In the coagulation mode, delivery of high-frequency energy is interrupted by periods of modulation. This alternation of frequency and interruption results in wider zones of lateral tissue coagulation and damage, resulting in coagulation and sealing of blood vessels. A variety of electrode tips are available including a cutting loop for excision of tissue, a roller ball or bar for coagulation and ablation, and a knife electrode for incision.
A new family of bipolar electrical generators (Versapoint, Gynecare of Ethicon, Somerville, New Jersey) has been developed. Electrodes have been designed in several configurations producing variable tissue effects. A ball tip can be used for vaporization with limited tissue desiccation, a spring tip for vaporizing larger amounts of tissue, and a twizzle tip for resecting and morcellating tissue. These tips have both active and return electrodes and require an electrolyte-containing medium such as saline. In contrast, if one is using a monopolar resectoscope, a nonelectrolyte distension medium such as glycine must be used.
Distension Media
Four basic types of distension media are used for hysteroscopy. The first type, CO2, is used primarily for diagnostic hysteroscopy in an office setting. Secondly, a high-viscosity medium such as Hyskon is used primarily with inflow only–type hysteroscopes. The third and fourth types are both low-viscosity solutions that are used with continuous flow hysteroscopes, electrolyte solutions and nonelectrolyte solutions. The choice between an electrolyte and nonelectrolyte solution will depend on the use of monopolar versus bipolar electrocautery.
For diagnostic procedures in the office, many physicians choose CO2 as the distension medium. CO2 use requires a hysteroflator that delivers the gas at preset intrauterine pressures and has regulated flow rates. CO2 may be used with either a small diagnostic rigid hysteroscope or a flexible hysteroscope and does not require a return channel for continuous flow, because the CO2 gas will escape from the cervix or through patent fallopian tubes into the peritoneal cavity where it is absorbed. Starting pressures for CO2 are usually between 50 and 75 mm Hg. If adequate distension is not achieved, it may be necessary to increase the intrauterine pressure to a maximum of 100 mg Hg or a maximal flow of 100 mL/minute. Higher pressures or flow rates may produce a gas embolus and fatalities have been reported. CO2 will give an ideal view of a uterus that is not bleeding, because light reflection is identical to that of room air. However, any blood or mucus within the endometrial cavity will require changing to a liquid medium.
Thirty-two percent high-molecular-weight Dextran-70, Hyskon, was used commonly as a liquid distension medium for operative hysteroscopy for many years prior to the evolution of hysteroscopes that accommodate continuous flow. Its nonmiscibility with blood allowed its use when either blood or mucus was present in the endometrial cavity or bleeding is anticipated. Hyskon is compatible with either the Nd:YAG laser or electric cautery devices. When using Hyskon as the distension medium, its delivery requires significant constant pressure to overcome the resistance of a high-viscosity fluid flowing through a standard diagnostic sheath. The major disadvantage of Hyskon is the difficulty in cleaning the solution from the instruments and stopcocks. If the instrumentation is not thoroughly cleaned, the dextran crystallizes and results in clouding of the hysteroscope lens and freezing of stopcocks. Rarely, patients may have an anaphylactic reaction to the dextran. Intravascular absorption of Hyskon will also result in a ten-fold increase of intravascular volume, with accompanying cardiovascular overload and pulmonary edema. Careful monitoring of the amount of Hyskon intravasated during the procedure is mandatory, and absorption of 100 to 200 mL of Hyskon should warrant terminating the procedure. Because the molecular weight of Hyskon exceeds that which can pass into the circulation from the peritoneal cavity, spill through the fallopian tubes is inconsequential.
Operative hysteroscopy most commonly now uses low-viscosity solutions, which can be either electrolyte solutions or nonelectrolyte solutions. If monopolar resectoscopes are used, this equipment requires nonelectrolyte solutions, so that the flow of energy will be directed from the electrode tip into the tissue and not allowed to “short circuit” through an electrolyte-containing medium throughout the entire uterus. Nonelectrolyte solutions that have been used commonly for operative hysteroscopy include 1.5% glycine, sorbitol, 5% mannitol, and dextrose in water. Significant intravasation of distension medium may occur with resectoscope use. As tissue is resected, venous channels within the endometrium and myometrium are opened, and the pressure of the distension medium will result in the absorption of these solutions. The primary complications associated with nonelectrolyte low-viscosity solutions include fluid overload and hyponatremia. Fluid overload may result in pulmonary edema, and severe hyponatremia may result in neurologic sequela such as confusion, seizures, and even death. Intraoperative monitoring of inflow and outflow must be performed every 5 to 10 minutes throughout the procedure, and a discrepancy between 500 and 1,000 mL with nonelectrolyte solutions should warrant termination of the procedure. Glycine use has also been reported to cause hyperammonemia because of its conversion from glycine to ammonia by the liver.
Electrolyte solutions, such as normal saline or lactated Ringer solution, are used with bipolar electrical devices or for continuous flow diagnostic hysteroscopy. Because bipolar devices contain both the active and return electrodes at the electrode tip, electrolytes are needed to complete the electrical circuit. The primary complication associated with electrolyte solutions is fluid overload, and a discrepancy of 1,500 to 2,000 mL during the procedure warrants termination of the procedure.
During operative hysteroscopy with significant operating time and use of large amounts of distension medium, the anesthesiologist should keep intravascular fluid replacement to a minimum to avoid fluid overload. Anesthesia personnel should also monitor the patient carefully for electrolyte abnormalities when using nonelectrolyte solutions and anaphylactic shock when using Hyskon.
General Technique
Hysteroscopy can be difficult to perform during the luteal phase because of the abundance of endometrial tissue. Performing hysteroscopy during the early to middle follicular phase should ensure adequate visualization of the uterine cavity. Alternatively, the endometrium can be suppressed with 2 to 4 weeks of progestin therapy, or hysteroscopy may be performed at any time in a patient taking oral contraceptives because of the dominant atrophy effect of progestin. Gonadotropin-releasing hormone (GnRH) analogs have most commonly been used to prepare the endometrium for endometrial ablation. At least 4 weeks of preoperative treatment are required for GnRH analogs such as leuprolide acetate (Depo-Lupron), because these medications are initially agonists and will actually increase estrogen output for the first 7 to 10 days before subsequent down-regulation of the pituitary ovarian axis and subsequent endometrial atrophy.
The cervix should be dilated no larger than the outer diameter of the hysteroscope that will be used. With many larger operative hysteroscopes, this will require dilation of the cervix to at least the diameter of a 20-French Hank dilator or a 9/10-French Hegar dilator. Care should be taken to avoid cervical lacerations and uterine perforation during cervical dilation.
With insertion of the hysteroscope, the cervical canal can be visualized and the hysteroscope guided into the endometrial cavity under direct vision. If over-dilation of the cervix has occurred and the distension medium cannot be kept within the endometrial cavity, an additional tenaculum may be placed on the posterior lip of the cervix, or a special four-pronged tenaculum can be used to compress the cervix around the hysteroscope. The cervical canal and internal os will appear off-center within the field of view when using offset-angle lenses. When the angle of the lens is oriented to look downward, the internal os will appear at the 12 o'clock position. If the telescope is inverted and the lens pointed upward, the os will appear in the 6 o'clock position. The latter position is useful for viewing a retroverted uterus. The surgeon always should maintain the camera position in a straight-up-and-down configuration so that the view on the screen corresponds anatomically to the patient's position. As the hysteroscope is rotated to visualize the entire endometrial cavity, one hand should be kept on the camera to prevent its rotation, or the view on the monitor will be oriented improperly.
With insertion of the hysteroscope, the cervical canal should be visualized and the endometrial cavity entered carefully through the internal os. If adequate visualization is prevented by blood and mucus, continuous flow of the distension medium should be maintained for 30 to 60 seconds to wash out blood and debris. If the field of view still appears red, the hysteroscope should be pulled back 1 to 2 centimeters, because it is a common mistake to insert the hysteroscope too far and the lens may be abutting the uterine fundus. Visualization can also be compromised by inadequate distension of the uterine cavity because of insufficient intrauterine pressure. The fluid delivery devices should be checked to ensure adequate pressure, or if a gravity system is being used, the height of the bag above the patient should be extended. Careful adjustment of the outflow should be made to clear any ongoing bleeding and debris without decreasing intrauterine pressure or using extremely large volumes of distension medium.
The entire endometrial cavity should be inspected carefully, including the identification of both tubal ostia, the fundus, and the anterior and posterior portions of the uterine wall. Video documentation of the intraoperative findings is useful. If operative techniques are to be used during the hysteroscopy, inflow and outflow should be measured carefully and reported to the surgeon every 5 to 10 minutes. If significant bleeding or a long operative time is anticipated, vascular constriction through the paracervical injection of a dilute pitressin solution may be used. Care should be taken that pitressin is not injected intravascularly, because reports of fatalities with inadvertent intravenous administration have been reported.
ENDOMETRIAL ABLATION
Approximately 35% of gynecologic complaints concern menorrhagia, and it is estimated that 60% of these women ultimately will be treated with hysterectomy. Endometrial ablation originally was developed as an alternative treatment for patients who are medically too unstable for the surgical stress of hysterectomy. Since its original development in the 1980s, however, patient selection criteria have now expanded and hysteroscopic endometrial ablation is viewed by many as an alternative to hysterectomy, even in healthy patients. Prior to consideration of hysteroscopic endometrial ablation, endometrial pathology needs to be excluded with either a combination of endometrial biopsy to rule out hyperplasia or carcinoma and transvaginal ultrasonography with saline infusion to rule out polyps or submucous myomas or, alternatively, office diagnostic hysteroscopy could be performed with directed biopsies.
Because the goal of an endometrial ablation is the artificial creation of intrauterine synechiae, many experts feel that preoperative preparation of the endometrium with an GnRH agonist or continuous progestin will maximize the chance of adequate scar formation within the endometrial cavity postoperatively. Alternatively, some authors perform a mechanical preparation of the endometrium using a sharp curette or suction curettage immediately prior to endometrial ablation. This technique has the advantage of being able to immediately perform the procedure without a lengthy preoperative medical suppression of the endometrium. The disadvantage of a mechanical preparation, however, is the possibility of inadequate visualization during the procedure because of bleeding and the possibility of a compromised outcome secondary to inadequate destruction of the endometrial basalis.
Endometrial ablation can be done either with the Nd:YAG laser or the hysteroscopic resectoscope, using either a wire lube or roller ball technique. The Nd:YAG laser system uses a 600-µ bare fiber with power settings of 55 to 70 watts. The Nd:YAG laser penetrates 4 to 5 mm into the endometrium, destroying not only the superficial endometrial layers but also the endometrial basalis and superficial myometrium. A touching technique was described originally, dragging the fiber against the endometrium, thus destroying the endometrium and superficial myometrium by vaporization and necrosis. Alternatively, a nontouch technique with the higher power setting has been described in which the fiber is held perpendicular to the endometrium without touching the surface, achieving a deep coagulation effect. Many practitioners use a combination of the two techniques, and results of the two techniques appear comparable.
Due to the expense of laser ablation, electrosurgical ablation is performed more commonly. Most resectoscopes use monopolar electrodes, necessitating a nonelectrolyte low-viscosity medium. Hysteroscopic resection of the endometrium has been described using a loop electrode to excise strips of endometrium, although the incidence of uterine perforation is reportedly higher with this technique when compared with a roller ball or laser ablation. Most commonly, a roller ball technique is used. With a roller electrode, a blend 1 setting with 70 to 140 watts of power is used, depending on the width and thickness of the electrode. This current will allow consistent penetration and destruction of the uterine tissue. Care must be taken to ensure adequate ablation of the uterine cornu and to avoid destruction of the endocervical canal to prevent cervical stenosis.
Extensive studies of the outcome following endometrial ablation have been published. Approximately 80% to 90% of women will have a significant reduction of their menorrhagia and will be satisfied with the outcome, including approximately 25% to 40% of women experiencing amenorrhea postoperatively.
Complications of endometrial ablation include a 10% hysterectomy rate because of dissatisfaction with the outcome of surgery. In addition to the immediate postoperative complications previously discussed, there also have been reports of isolated endometrial carcinoma in areas of the uterus not adequately ablated and symptomatic hematometra developing in loculated areas of inadequate ablation. Although most women are sterile after this procedure, intrauterine pregnancies can occur and patients should be counseled to use adequate contraception.
HYSTEROSCOPIC SEPTUM RESECTION
The septate uterus is the most common congenital uterine malformation associated with recurrent reproductive failure and obstetric complications. The appearances of a septate uterus and bicornuate uterus are extremely similar on hysterosalpingogram, and the distinction must be made by demonstrating a normal external fundal contour with a uterine septum, as opposed to the presence of two uterine horns in a bicornuate uterus. The uterine septum may be thin or broad and may be of varying length, from an exaggerated arcuate appearance to total division of the uterine corpus, possibly including the cervix (Fig. 47.1). Indications for hysteroscopic resection of a uterine septum include repeated first- or second-trimester losses, a history of premature labor and delivery and, possibly, concurrent infertility.
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FIG. 47.1. Hysteroscopic view of a uterine septum extending down to the lower uterine segment before division. |
The hysteroscopic approach to the division of the uterine septum is performed almost exclusively today rather than the classic transabdominal resection or incision of the septum performed prior to the 1970s. The hysteroscopic approach allows for ambulatory treatment of this disorder and, because the uterine wall has not been invaded, cesarean delivery is not indicated postoperatively.
After adequate documentation of the diagnosis of a septate uterus and the exclusion of concurrent causes of pregnancy wastage, the surgery should be scheduled during the early follicular phase to allow adequate visualization of the septum. The use of GnRH analogs or other drugs to induce endometrial suppression may result in the iatrogenic formation of postoperative intrauterine scar formation unless postoperative estrogen replacement is given. Semi-rigid scissors are most commonly used to divide uterine septa (Fig. 47.2). The uterine septum is usually avascular and cautery is typically unnecessary. Under direct visualization, the septum is incised at its midpoint. As the incision is carried toward the fundus, the septal tissue normally retracts anteriorly and posteriorly into the myometrial wall, and resection of tissue usually is not needed. When the uterine cavity is symmetric, or when normal myometrial tissue is observed because of bleeding, the dissection should stop (Fig. 47.3). It is also useful to perform concurrent laparoscopy to both visualize the normal fundal contour before dividing the septum, as well as to guide the direction and extent of the dissection hysteroscopically.
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FIG. 47.2. Uterine septum is being divided by hysteroscopic rigid scissors. |
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FIG. 47.3. The uterine septum has been resected completely and a contour of the fundus is normal, with normal myometrial tissue visible. |
The septum also can be divided with either fiberoptic lasers or cutting loop resectoscopes. The disadvantages of these techniques include additional instrumentation and further complications should uterine perforation occur. When perforation occurs with hysteroscopic scissors, bleeding is unlikely and damage to surrounding structures is rare. When uterine perforation has occurred using an electrical cutting loop or laser fiber, damage to the surrounding bowel is possible. There is also concern that these modalities may damage surrounding normal myometrial and endometrial tissue.
Although some surgeons routinely administer high-dose estrogen therapy for 30 days postoperatively, randomized studies have shown no benefit when used in normally cycling women. Similarly, an intrauterine splinting device such as a pediatric Foley catheter has been advocated by some authors but usually is not needed because of the rapid reepithelialization of the endometrial cavity postoperatively.
Normal reproductive outcome following the division of a uterine septum is reported to be between 70% and 85% term delivery rate in patients with prior recurrent spontaneous abortions. Pregnancy outcome is equal with all three methods of septum division.
HYSTEROSCOPIC MYOMECTOMY
Uterine leiomyomas are the most common benign tumors of the uterus, and submucous myomas are common causes of menorrhagia and abnormal uterine bleeding. Submucous myomas also are associated with recurrent pregnancy loss and infertility. The evaluation of abnormal uterine bleeding and menorrhagia should include either a diagnostic hysteroscopy or a saline infusion sonohysterography to diagnose submucous myomas. Blind procedures, such as endometrial biopsy and dilation and curettage, will commonly miss these tumors. Most submucous myomas do not have a pedicle but project into the endometrial cavity with a broad base. Myomas that have greater than 50% of their volume projecting into the cavity and are less than 3 to 4 cm in size can be approached adequately for resection hysteroscopically. It is often useful to pretreat patients with a GnRH analog prior to a hysteroscopic myomectomy to shrink the myoma, as well as thin the endometrium. If the patient is anemic from menorrhagia, GnRH-agonist pretreatment also will allow her a period of amenorrhea and permit her hemoglobin level to normalize.
The resectoscope with a loop electrode is used commonly to shave the myoma until it is flush with the endometrial cavity. Power settings of 100 to 120 watts are used. With unipolar devices, a nonelectrolyte solution must to be used as the distension medium. The loop should be advanced past the myoma, and resection of strips of tissue is accomplished by pulling the loop toward the operator (Fig. 47.4). This technique will minimize the risk of uterine perforation. It is frequently necessary to remove the chips of tissue when they become so numerous as to obscure the surgical view. After removal of the resectoscope, a uterine polyp forceps can be used to blindly remove the chips. Even if all the tissue fragments are not removed, they will be expelled from the uterus with the next menstrual period.
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FIG. 47.4. A submucous myoma is being resected with a resectoscope loop electrode. |
It may be useful to reduce intraoperative bleeding and reduce intravasation of distension medium by injecting a dilute solution of pitressin, 20 units per 100 cc injectable saline, paracervically prior to the endometrial resection to achieve vascular constriction. Care should be taken not to inject this solution intravascularly, because deaths have been reported. A total of 5 to 10 cc is usually sufficient. Intraoperatively, small bleeding vessels may be coagulated with the loop electrode using 40 watts of coagulation current.
Bipolar systems have been developed (Versapoint, Gynecare, a division of Ethicon), which cause vaporization of tissue. Because these devices use a bipolar electrode, an electrolyte solution is needed as the distension medium. This system requires its own generator and will not work with other electrical generators such as Valley Lab's product. The advantage of these systems is the prevention of multiple tissue fragment generation as the technique vaporizes tissue. If pathologic diagnosis is desired, the tips can be used to isolate and remove a portion of tissue to be sent to the pathology department.
When performed for menorrhagia, success rates of hysteroscopic myomectomy have been reported in approximately 80% of patients. Conception rates have been reported between 43% and 63% following hysteroscopic myomectomy in previously infertile women.
HYSTEROSCOPIC POLYPECTOMY
Endometrial polyps are diagnosed in approximately 20% of women with abnormal uterine bleeding. This diagnosis usually requires either direct visualization of the polyp with a diagnostic hysteroscope or the visualization of a polyp using saline infusion sonohysterography. Hysteroscopically, endometrial polyps generally are more often pedunculated than submucous myomas and have a softer, fleshier appearance (Fig. 47.5).
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FIG. 47.5. An endometrial polyp is seen hysteroscopically as a soft fleshy growth. |
Depending on the size of the endometrial polyp, it may be removed by one of several techniques. With a small pedunculated polyp, grasping the polyp stalk with a hysteroscopic grasper and rotating of the grasper to remove the polyp can be performed easily (Fig. 47.6). With larger polyps or polyps with a larger base, a cutting loop resectoscope should be used. By resecting the base of the polyp with the loop electrode, the polyp subsequently can be removed intact with grasping forceps. If a small portion of the base remains, it can be destroyed with the loop electrode. Care should be taken not to destroy adjacent normal endometrial tissue to prevent postoperative adhesion formation.
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FIG. 47.6. A rigid grasper is placed through the hysteroscope to grasp the base of an endometrial polyp for removal. |
ASHERMAN SYNDROME
Intrauterine adhesions or synechiae, Asherman syndrome, may develop when opposing endometrial surfaces are damaged and heal as a coalescing adhesion. This typically occurs when inflammation or infection persists after spontaneous first-trimester abortion and when estrogen production is low. Patients who have had late postpartum curettages for retained placental fragments are at high risk for the development of Asherman syndrome (Fig. 47.7). Postpartum, estrogens of placental origin are metabolized rapidly and ovarian suppression continues for several weeks. With the absence of estrogen, the endometrium will fail to proliferate and reepithelialize damaged areas of endometrium following a curettage. Any concurrent inflammation or infection will increase the risk of intrauterine synechiae. Patients who have had elective abortions or postabortal curettages for any reason are also at risk for the development of intrauterine adhesions. The patient with Asherman syndrome may have amenorrhea if the extent of the adhesions is severe, but more commonly it manifests with normal menses or mild hypomenorrhea with recurrent spontaneous abortion or with infertility. The diagnosis of Asherman syndrome can be made by hysterosalpingogram, saline infusion sonohysterography, or direct visualization with diagnostic hysteroscopy.
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FIG. 47.7. The hysteroscopic appearance of a retained placental fragment 1 month postpartum. |
Intrauterine adhesions should be lysed with hysteroscopic scissors under direct visualization. This procedure is straightforward with mild to moderate cases of Asherman syndrome but can be very complicated in severe cases with complete obliteration of the endometrial cavity. In difficult cases, concurrent laparoscopy can be useful to guide the hysteroscope. Pockets of normal endometrium are used as guides to the lysis of thick adhesion bands. Both cornu of the uterus ultimately should be visualized, and the uterine contour should be relatively normal at the end of the procedure.
Postoperatively, most practitioners will place patients with Asherman syndrome on high-dose estrogen replacement, Premarin (conjugated estrogens) 2.5 mg twice daily, or its equivalent, for 30 days to help induce proliferation of any remaining endometrium to reepithelialize the previous site of adhesions. Stenting of the uterus with a pediatric Foley catheter balloon filled with approximately 3 cc of saline for 1 week postoperatively also will prevent the damaged endometrial surfaces from coming immediately into contact with one another. With this foreign body in place, antibiotics should be used to prevent infection.
PROXIMAL TUBAL CANNULATION
Approximately 20% of tubal occlusion occurs in the intramural portion of the fallopian tube at the uterotubal junction. Pathologically, proximal occlusion may be caused by debris plugs or fibrosis from inflammation, intraluminal endometriosis, or salpingitis isthmica nodosa. The diagnosis of proximal tubal occlusion often is made by hysterosalpingography. However, a definitive diagnosis cannot be made with this technique, because uterine muscle spasm falsely suggesting proximal tubal occlusion may be a consequence of the procedure itself. If pathologic proximal tubal occlusion is suspected, selective injection of contrast medium into the fallopian tubes may be performed either fluoroscopically or via hysteroscopy with concurrent laparoscopy. The latter technique has the advantage of simultaneously inspecting the distal portion of fallopian tube for damage. If the patient has both a proximal and a distal occlusion, the tubes are not candidates for surgical correction, and in vitro fertilization should be recommended. If selective injection of one or both of the fallopian tubes does demonstrate proximal tubal occlusion, then hysteroscopic cannulation of the fallopian tube can be performed immediately.
Hysteroscopically, a flexible guidewire, 0.3 to 0.8 mm in outer diameter, is guided into the uterine cornu. The softness of this guidewire usually allows it to penetrate the occlusion while staying within the tubal lumen. When the guidewire is seen in the proximal portion of the fallopian tube laparoscopically, a soft Teflon catheter of 1.3-mm outer diameter is pressed over the guidewire until this is also within the proximal portion of fallopian tube. The guidewire can then be removed and methylene blue injected through the Teflon catheter to confirm tubal patency.
Approximately 80% of proximal tubal occlusions can be cannulated successfully. Complications include perforation of the guidewire through the proximal portion of fallopian tube, but this rarely results in troublesome bleeding or infection. Intrauterine pregnancy rates have been reported as approximately 30% to 40% following proximal tubal cannulation.
SUMMARY POINTS
· The development of good hysteroscopy skills is important to gynecologists so that they may use the diagnostic and operative advantages these techniques offer.
· Careful attention to the surgical technique and particularly the distension medium employed is important in order to perform hysteroscopy safely.
· Diagnostic hysteroscopy is the gold standard for evaluation of the endometrial cavity.
· Operative hysteroscopy offers an outpatient surgical approach to many uterine problems including submucous and intracavitary leiomyomata, endometrial polyps, intrauterine synechiae, uterine septa, and proximal tubal occlusion.
· Endometrial ablation offers women an alternative to hysterectomy for the management of abnormal uterine bleeding or menorrhagia.
SUGGESTED READINGS
Instrumentation, Distension Media, and General Technique
Bain C, Parkin DE, Cooper KG. Is outpatient diagnostic hysteroscopy more useful than endometrial biopsy alone for the investigation of abnormal uterine bleeding in unselected premenopausal women? A randomised comparison. Br J Obstet Gynecol 2002;109:805–811.
Bronz L. Hysteroscopy in the assessment of postmenopausal bleeding. Contrib Gynecol Obstet 2000;20:51–59.
Fay TN, Khanern N, Hosking D. Out-patient hysteroscopy in asymptomatic postmenopausal women. Climacteric 1999;2:263–267.
Hucke J, De Bruyne F, Balan P. Hysteroscopy in infertility-diagnosis and treatment including falloposcopy. Contrib Gynecol Obstet 2000;20:13–20.
Shirk GJ, ed. The video encyclopedia of endoscopic of endoscopic surgery for gynecologists. St Louis: Medical Video Productions, 1994.
Wiser F, Temper C, Kurz C, et al. Hysteroscopy in 2001: a comprehensive review. Acta Obstet Gynecol Scand 2001;80:773–783.
Endometrial Ablation
Bratschi HU. Hysteroscopic endometrial resection. Contrib Gynecol Obstet 2000;20:121–136.
Kochli OR. Endometrial ablation in the year 2000-do we have more methods than indications? Contrib Gynecol Obstet 2000;20:91–120.
Lethaby A, Hickey M. Endometrial destruction techniques for heavy menstrual bleeding (Cochrane Review). Cochrane Database Syst Rev 2002;2:CDO01501.
Ravi B, Schiavello H, Chandra P, et al. Safety and efficacy of hysteroscopic endomyometrial resection-ablation for menorrhagia. J Reprod Med 2001;46:717–723.
Hysteroscopic Septum Resection
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Nawroth F, Schmidt T, Freise C, et al. Is it possible to recommend an “optimal” postoperative management after hysteroscopic metroplasty? A retrospective study with 52 infertile patients showing a septate uterus. Acta Obstet Gynecol Scand 2002;81:55–57.
Hysteroscopic Myomectomy
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Tercanli S, Kochli OR, Hoesli I, et al. Differentiation and management of endometrium abnormalities and leiomyomas by hydrosonography. Contrib Gynecol Obstet 2000;20:69–80.
Vercellini P, Zaina B, Yaylayan L, et al. Hysteroscopic myomectomy: long-term effects on menstrual pattern and infertility. Obstet Gynecol 1999;94:341–347.
Hysteroscopic Polypectomy
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Asherman Syndrome
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Proximal Tubal Cannulation
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Dumesic DA, Dhillon SS. A new approach to hysteroscopic cannulation of the fallopian tube. J Gynecol Surg 1991;7:7–9.
Thompson KA, Kiltz RJ, Koci T, et al. Transcervical fallopian tube catheterization and recanalization for proximal tubal obstruction. Fertil Steril1994;61:243–247.
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Complications
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