• SBE ISGE Joint Meeting - Sao Paulo September 2009
• XVIII Annual Congress March 2009 Pattaya,Thailand
• XVII Annual Meeting - Bari Italy
• ISGE Annual Meeting, Japan March 19-23 2007

Hysteroscopy

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Richard S Guido, MD
Dale W Stovall, MD

INTRODUCTION — A hysteroscope is a thin, telescope-like device inserted into the uterus via the vagina and cervix that allows direct visualization of the endometrial cavity and tubal ostia. An operative hysteroscope enables the physician to make diagnoses, obtain targeted specimens for histological examination, apply therapies (eg, endometrial ablation), and perform a variety of surgical procedures (eg, adhesiolysis and myomectomy). Dilation and curettage (D&C) without hysteroscopy is a "blind" procedure that can miss focal disease. By comparison, hysteroscopy is accurate, cost-effective, convenient, highly acceptable to patients, and offers the option of definitive treatment as well as diagnostic evaluation.

INDICATIONS — Hysteroscopy can be performed as a diagnostic or therapeutic procedure, or both.

Diagnostic hysteroscopy — Indications for hysteroscopy in the gynecologic patient include:

   Evaluation of abnormal uterine bleeding.

   Evaluation of suspected müllerian anomalies.

   Assessment of abnormal findings on hysterosalpingogram (HSG).

   In conjunction with diagnostic laparoscopy performed during an infertility evaluation.

Hysteroscopy can detect polyps and submucosal leiomyomas in women with menorrhagia with greater accuracy than D&C or transvaginal ultrasonography [1-3]. As an example, one study comparing hysteroscopy with other diagnostic techniques observed a focal intrauterine lesion in about one-half of patients evaluated for abnormal uterine bleeding; diagnostic sensitivity was significantly better with hysteroscopy than with transvaginal ultrasound or blind biopsy (100, 60, and 4 percent, respectively) [2].

The accuracy of hysteroscopy alone for the diagnosis of endometrial cancer and hyperplasia was illustrated by a large, well-designed systematic review of 65 observational studies including over 26,000 women (29 percent postmenopausal) with abnormal uterine bleeding [4]. Hysteroscopic findings were compared with endometrial histology obtained from specimens obtained separately by curettage, blind or directed biopsy, or hysterectomy. The procedure was successfully performed in over 95 percent of patients. The prevalence of pathology in these women was endometrial cancer (4 percent overall, 11 percent in postmenopausal women), endometrial cancer or hyperplasia (11 percent), focal lesions (18 percent) [4]. Hysteroscopy was found to be a safe and effective tool for diagnosis of endometrial disease. The overall sensitivities and specificities for diagnosis of endometrial cancer were 86 and 99.2 percent, respectively, and for endometrial cancer or hyperplasia 78 and 95.8 percent, respectively. Although positive hysteroscopic findings are highly predictive of endometrial cancer (posttest probability of cancer 72 percent) and thus warrant further evaluation (directed biopsy) and management (see "Clinical features and diagnosis of endometrial cancer"), a negative examination (and in the absence of biopsies) is not sufficient to exclude cancer (posttest probability of cancer 0.6 percent), especially in women with persistent bleeding.

Therapeutic hysteroscopy — Hysteroscopy also has many therapeutic indications, including:

   Myomectomy of submucous myomas

   Endometrial polypectomy

   Removal of an intrauterine device

   Excision of intrauterine adhesions or septa

   Ablation of the endometrium in women with menorrhagia unresponsive to medical therapy

   Sterilization

CONTRAINDICATIONS — Contraindications to hysteroscopy include pelvic infection, excessive uterine bleeding, cervical cancer, and the inability to undergo anesthesia. Hysteroscopy can spread lower genital tract infections to the upper genital tract; upper genital tract infections increase the risk of uterine perforation [5]. Therefore, pelvic infections should be evaluated and treated appropriately. Although women with uterine bleeding may be candidates for hysteroscopy, heavy bleeding will obscure the visual field and render the procedure ineffective. These women should be diagnosed and treated with D&C. (See "Endometrial sampling and dilation and curettage").

Hysteroscopy can be performed in pregnancy for removal of an coexisting intrauterine device. However, pregnancy is generally considered a contraindication to this procedure. Postpartum hysteroscopy may be useful for evaluation and treatment of retained products of conception in the absence of heavy bleeding or infection.

INSTRUMENTATION

Hysteroscopes — The two major types of hysteroscopy are panoramic and contact hysteroscopy.

   The rigid, panoramic hysteroscope, which is derived from the cystoscope, uses distending media to obtain a wide-angle view of the uterine cavity. This hysteroscope takes advantage of a system of lenses and prisms to give the operator a well-illuminated image with excellent contrast and resolution. The most widely used panoramic hysteroscopes have an OD of 4 mm, but thinner scopes with an OD of 2.7 mm have been developed for office procedures [6].

Most panoramic hysteroscopes are focused at infinity, but some have adjustable focusing mechanisms. The overall magnification of the endoscope is the product of the magnification of the eyepiece and the objective lens and is inversely proportional to the distance of the tissue from the objective lens. A prism at the proximal end of the hysteroscope is used to form an upright image.

   Contact hysteroscopy was developed as a simple mechanism for viewing the uterine cavity without the use of a distending media [7]. Only tissue that comes in direct contact with the scope can be viewed. Unless the uterine cavity is explored in a slow, systematic fashion, significant pathology can be missed. Therefore, contact hysteroscopy is inferior to the panoramic hysteroscopy for evaluation of the endometrium. The instrument is 200 mm in length with outer diameters (ODs) of 4, 6, or 8 mm. The eyepiece has a magnification of 1 X 1.6 and adjustable focus with a focal length of 4 mm.

Both panoramic and contact hysteroscopes are monocular and provide little depth perception. They are available with different viewing angles, from 0 to 70 degrees. Zero and 15 degree scopes are most commonly used for diagnostic procedures. Larger angles of deflection are used in operative procedures. The hysteroscopes are easily attached to video monitoring systems.

Sheaths — The panoramic hysteroscope is inserted and securely fastened into a metallic sleeve or sheath. Removable obturators are available for easy introduction of the sheath into the uterine cavity. Obturators are especially useful when dilation is difficult or when large sheaths are being used. Diagnostic sheaths have an OD from 3.3 to 5.0 mm and operative sheaths have an OD from 7.0 to 10.0 mm. Both diagnostic and operative sheaths are fitted with stopcocks or ports for the instillation of distending media. Some operative sheaths have isolated, dual ports and provide continuous laminar flow of distending media.

Operative sheaths are designed to allow the passage of one or more operative instruments. Simple sheaths use the distending media channel for the insertion of instruments. Although this method is easy and allows one to use a small-diameter sheath, leaks are commonly encountered.

Other operative sheaths contain permanently attached operative tools, such as biopsy instruments, forceps, and scissors. A right-angle hysteroscope allows for direct insertion of rigid operating instruments; these sheaths have an OD of 8 mm. Some of the more advanced operative sheaths contain as many as four channels, two for placement of the hysteroscope and the distending media and two for use by accessory instruments.

Flexible hysteroscopes — Flexible fiberoptic hysteroscopes were patterned after the gastrointestinal endoscope  [8]. The distal tip can be deflected upward or downward from 130 to 160 degrees. Both the diagnostic and operative scopes deliver distending media through a 1 mm channel. Some diagnostic, flexible hysteroscopes have an OD as small as 3.5 mm, while flexible hysteroscopes with single operating channels have ODs starting at 5.0 mm. Each of these hysteroscopes can be inserted with little or no cervical dilation.

This instrument is especially useful for evaluating the uterine cavity and tubal ostia in patients with an irregularly shaped uterus. It can be used when performing proximal tubal cannulation and for lysis of adhesions located laterally, which are difficult to reach with the rigid hysteroscope.

Resectoscope — The hysteroscopic resectoscope is a modification of the urologic resectoscope. Its assembly requires some practice and should be mastered before surgical procedures are undertaken. The sheath has an OD of 8 mm and includes both inflow and outflow ports for distending media. The resectoscope is equipped with continuous flow and provides excellent irrigation for operative procedures. If surgical debris blocks the operative field, the resectoscope can be removed while the sheath is left in place. This allows for removal of large debris while maintaining cervical dilation.Electrosurgical instruments can also be inserted into the apparatus. The device has a spring handle that allows the surgeon to move the attached surgical instrument inward and outward.

The resectoscope is useful for removing submucous myomas, uterine septa, endometrial polyps, and intrauterine adhesions, and for endometrial ablation. The woman must be grounded and a nonelectrolyte, nonconducting, distending media must be used.

Operative instruments — An assortment of rigid, semirigid, and flexible instruments have been developed or adapted for hysteroscopic surgery. The rigid and semirigid instruments include scissors, grasping forceps, and biopsy forceps. The flexible instruments are a group of specifically adapted catheters.

Rigid instruments can be categorized into two types. One type is permanently fixed to the end of an operative sheath. Since these instruments must be maneuvered with the hysteroscope, they can be awkward to manipulate. Other types of rigid instruments, including scissors, grasping forceps, and biopsy forceps, are inserted through an offset operating hysteroscope.

By comparison, semirigid instruments can be inserted through the operative port of an in-line hysteroscope. These instruments are small (7 French) and fragile. Special care should be taken when handling them as the handle, shaft, and tips can be easily damaged. Flexible catheters can also be inserted through the hysteroscopic sheath for tubal cannulation and selective chromotubation. A 3-French whistle tip catheter works well for this purpose.

  Electrocautery and laser — Electrocautery instruments, such as a loop electrode, roller ball, and punctate electrode, have been adapted for the resectoscope. Both the roller ball and the loop electrode can be used for endometrial ablation. In addition, the loop, which ranges in size from 24 to 27 French, can be used for excision of submucous myomas and the resection of uterine septa. The punctate electrode is applied for pinpoint coagulation.

Lasers (eg, neodymium-yttrium-aluminum-garnet (Nd:YAG), potassium-titanyl-phosphate (KTP), and argon) are delivered by fiberoptics and, unlike the carbon dioxide laser, these can freely pass through liquid distending media. The Nd:YAG laser is invisible with a wavelength of 1,064 nm. It penetrates tissue to a depth of 3 to 4 mm and exerts its major effects below the tissue surface. The principle effect of the Nd:YAG is photocoagulation, not vaporization. It has been used in endometrial ablation; however, in this author's experience, it offers few if any advantages over electrocoagulation and is more expensive.

Light source — Illumination for hysteroscopy is provided by a light source connected to the hysteroscope by a fiberoptic cable. Fiberoptics provide transmission of potent light from a given source to the hysteroscope without the production of significant heat. The fiberoptic system employs thousands of small glass fibers with a low refractory index cladding (ie, covering) and a high refractory index core. A compact light system can deliver sufficient illumination for both diagnostic and operative procedures.

The light cable fastens directly onto the hysteroscope. Adapters are made so that one may use a single light source for several different cables or hysteroscopes. Most of the contemporary light sources contain either halogen or xenon light sources. The xenon lamps are more expensive, but both provide adequate illumination for operative procedures, photography, and videotaping.

Distending media — The uterine cavity must be distended to perform panoramic hysteroscopy. The ideal distending media is isotonic, nonhemolytic, nonconductive, nontoxic, rapidly cleared from the body, and provides ample visualization. If a surgical procedure is planned, the distending media should minimize uterine bleeding or maintain a clear visual field, or both. The most commonly used media are carbon dioxide, low viscosity fluids, and high molecular weight dextran 70 [9]. The angle of view and magnification varies with the refractory index of the distending media. Gaseous media allow perception of the maximal angle of view, while liquid media reduce the angle of view [10].

  Carbon dioxide — Carbon dioxide as a distending media provides an excellent field of view, is widely available, has a long history of safety in tubal patency testing, is rapidly absorbed, and makes cleaning of instruments easy. It is an exceptional distending media for diagnostic office hysteroscopy, but less useful in operative hysteroscopy because intrauterine bleeding usually results in the formation of bubbles that obscure the visual field.

Carbon dioxide must be insufflated with a special instrument. One such instrument uses a pressure set point, such as 100 mmHg, and gas is infused until this pressure is reached. Another insufflator has an adjustable flow rate with a maximum of 100 mL/min. The laparoscopic insufflator delivers 1 L/min or more of flow and should never be used for hysteroscopy due to the potential complication of an embolism.

  Low-viscosity media — There are two types of low-viscosity distending media: those that contain electrolytes and those that do not. The electrolyte-containing media include normal saline and lactated Ringer's solution and cannot be used with electrocautery. The electrolyte-free solutions are 5 percent dextrose, 1.5 percent glycine, and 3 percent sorbitol.

Low-viscosity media are usually delivered into the hysteroscopic sheath from 500 to 3,000 mL plastic bags. These large bags are either elevated above the patient and infused by the force of gravity or placed in a large blood pressure cuff and infused by pressurizing the cuff. Alternatively, low-viscosity fluids can be instilled into the uterine cavity by an electrically driven pump, which provides a more precise delivery of fluid at a constant pressure.

  High viscosity media — Hyskon is categorized as a high-viscosity distention media. It is a clear, viscous, sterile, nonpyogenic, electrolyte-free, nonconductive solution of dextran 70 in 10 percent dextrose. It has a tendency to crystallize if subjected to temperature variations or stored for long periods of time. Hyskon has the ability to attract large volumes of water when intravasated intravascularly, which may lead to electrolyte imbalances (see "Complications" below). The extent of systemic absorption of dextran 70 by the uterine and peritoneal cavities has not been ascertained. Hyskon must be poured slowly down the side of a container and then aspirated into two or more 50 mL plastic syringes for delivery to avoid the formation of air bubbles that may distort the visual field. The delivery tubing should be filled before being attached to the inflow valve on the hysteroscopic sheath. The sheath is then filled with Hyskon before it is inserted into the uterine cavity. The amount of solution used is rarely greater than 300 mL and the infusion pressure should not exceed 150 mmHg.

One of the major advantages of Hyskon is its inability to mix with blood, which maintains a clear visual field despite the presence of uterine bleeding. Electrosurgery can be performed with Hyskon because the solution is non-conductive. The major disadvantage of Hyskon is its tendency to adhere to surgical instruments. If the surgical instruments are not washed with hot water immediately after a procedure, the media can damage valves and optical components.

PREOPERATIVE PREPARATION — Before performing any procedure, the operating surgeon must fully inform the patient about the expected benefits, cost, chance for failure, potential risks, and alternatives. Elective hysteroscopic procedures should be performed during the proliferative phase of the menstrual cycle, as this provides the an optimal view of the uterine cavity. Secretory phase endometrium is thick, and thus can mimic endometrial polyps and lead to inaccurate diagnoses.

Patients may eat prior to office procedures performed with paracervical block only, otherwise they should fast for eight hours prior to the procedure. Administration of an oral nonsteroidal antiinflammatory drug one hour prior to office procedures can help reduce intraoperative and postoperative discomfort. Prophylactic antibiotics are not routinely administered, but have been recommended for women who require prophylaxis for subacute bacterial endocarditis [11].

Anesthesia — Intravenous sedation with paracervical block is adequate for office procedures; alternatively, general or regional anesthesia may be administered in the hospital or for complicated therapeutic procedures. In addition, consent should be obtained for possible laparoscopy (and in some cases laparotomy) when an operative hysteroscopy is scheduled.

OPERATIVE PROCEDURES — The woman is placed in the lithotomy position, antiseptically prepared, and draped. If she did not void prior to the procedure, the urinary bladder is drained. A side-opening speculum is inserted. The hysteroscope is put through the cervical os under direct endoscopic vision and the speculum removed. Ideally this is done with no or minimal cervical dilatation, but a tenaculum may be required. Although a video camera is not requisite, it is strongly recommended for the benefit of the surgeon and it is useful for teaching.

One of the most important factors in performing operative hysteroscopy is maintenance of a clear operative field. Besides using a distending media that does not mix with blood, such as Hyskon, this can be accomplished by either overdilating the cervical os and allowing the distending media to flow out around the hysteroscopic sheath or by using a sheath that provides continuous laminar flow of media. With the former method, the assessment of media outflow can be difficult. The author prefers a dual sheath or dual port system with an outflow port that can be directly connected to a vacuum collecting system. This gives an accurate assessment of the fluid deficit as less media is lost in the drapes, towels, or on the operating room floor. The surgeon should be updated regarding the fluid deficit every 10 to 15 minutes.

The uterus is an intrinsically vascular organ and its vascularity may be enhanced by uterine myomas or other pathology. However, intraoperative bleeding is generally not a significant problem because the liquid distending media usually exerts an intrauterine pressure of more than 90 mmHg, which exceeds end-arterial pressure. There is a risk of intravasation of distending media through open, low-pressure venous channels with subsequent fluid overload. Intracervical stromal injection of dilute vasopressin solution significantly decreases this process [12].

Postoperatively, both pelvic ultrasound and HSG can be used to determine whether a particular procedure was completely successful (eg, repair of a uterine anomaly, removal of a uterine leiomyoma, or cannulation of a proximal tubal obstruction). The appropriate timing for postoperative evaluation should be individualized and is based upon the recurrence of symptoms, difficulty of the procedure, and needs of the patient.

Myomectomy — The American College of Obstetrician and Gynecologists (ACOG) described the following preoperative criteria for myomectomy [13]:

   Infertility or recurrent pregnancy loss when myomas are believed to be the primary cause for the condition. A preoperative evaluation should be performed to exclude other causes of these conditions as myomas alone are responsible for infertility in only 2 to 3 percent of patients [14] and recurrent pregnancy loss is believed to be the result of uterine myomas or müllerian anomalies in fewer than 15 percent [15].

   Submucous leiomyomas causing menorrhagia.

Hysteroscopy is effective for removal of both broad-based and pedunculated, submucous myomas. A study of 94 women with up to 10 years follow-up reported only 16 percent of patients who underwent myomectomy and 8 percent of those who underwent both myomectomy and endometrial ablation required additional treatment [16]. However, there are no data regarding the efficacy of hysteroscopic myomectomy in women with recurrent pregnancy loss and little information regarding its effectiveness in the treatment of infertility. A systematic literature review found that only those fibroids with a submucosal or an intracavitary component were associated with adverse reproductive outcomes and suggested hysteroscopic myomectomy may be of benefit [17].

The author and colleagues use the resectoscope and loop electrode almost exclusively for hysteroscopic myomectomy. Hysteroscopic scissors, laser energy, or a knife electrode may also be utilized. The loop electrode can be used to cut directly through the base of a pedunculated myoma, or it can be used as a morcellating device to slowly "shave-away" a broad-based myoma; a combination of these two techniques is often needed. The loop should pass through the tissue with ease using a cut or blended cut and coagulation current of 100 to 120 watts.

The resection is begun by placing the loop just beyond the most cephalad portion of the fibroid and gradually drawing the loop toward the operator by moving either the loop alone through its spring mechanism or by moving the entire resectoscope. Both techniques are acceptable; each surgeon should use the technique he finds most effective.

The edges of the fibroid tend to fall inward as the middle is resected, thus increasing the panoramic view. When the operative field becomes obstructed by small pieces of myoma accumulating during resection, the inner sheath of the resectoscope can be removed. This allows drainage of the uterine cavity and will clear the field. Polyp forceps may be needed to remove larger debris. The tissue is collected for histologic examination.

The resection should not proceed past the level of the surrounding endometrial lining. Concurrent laparoscopy may be helpful for the less experienced surgeon, and its use should be decided on a case-by-case basis. There are no data to suggest that concurrent laparoscopy decreases operative complications and this author has found it to be useful only with large myomas or when completing an infertility evaluation. Uterine perforation during hysteroscopic myomectomy can lead to uterine rupture during a subsequent pregnancy [18].

The surgical area will become covered with newly proliferated endometrium postoperatively. Estrogen therapy has not been effective in decreasing intrauterine adhesions.

Preoperative treatment with a gonadotropin releasing hormone (GnRH) agonist might be useful for decreasing the size of submucous myoma(s), thus making resection less difficult. GnRH agonists have not been shown to be more effective than iron for improving the patient's preoperative hemoglobin. (See "Treatment of uterine leiomyomas"). The author does not advocate routine preoperative medical therapy for submucous myomas and has not used size limits as a contraindication for myoma resection, as long as the cavity can be visualized and the loop electrode can be placed safely around the lesion. Until proven otherwise, the author advocates oral iron therapy for treatment of chronically anemic patients.

Metroplasty — Lateral fusion defects of the müllerian ducts result in uterine anomalies that are associated with recurrent pregnancy loss. (See "Congenital anomalies of the uterus"). Once other etiologies for recurrent pregnancy loss are excluded, one may consider corrective surgery.

Historically, all müllerian anomalies were repaired via laparotomy. However, this procedure requires an incision through the uterus, which increases the risk of uterine dehiscence and necessitates a cesarean delivery. Other risks of an abdominal metroplasty include excessive blood loss, pelvic adhesions, and wound infection. Although bicornuate uteri are not repairable via hysteroscopy, a septate uterus can be approached hysteroscopically.

The author prefers the use of rigid or semirigid scissors to perform hysteroscopic metroplasty, as this avoids the risk of electrical or laser damage to the endometrium. Alternatively, one could use the resectoscope with loop electrode or laser. Concurrent laparoscopy is indicated if a definitive diagnosis of the type of anomaly has not been made. Concurrent laparoscopy is not essential and should be considered on a case-by-case basis.

During hysteroscopy, a thorough inspection of the cervical canal, endometrial cavity, tubal recesses, and tubal ostia is made. The septum is approached in its midposition using sharp dissection. Uterine septa are composed of fibrous tissue so intraoperative bleeding is usually minimal. As the dissection progresses, the uterine wall will separate. Sharp dissection is continued until the fibrous tissue is even with the beginning of the tubal recesses. In one study of 103 women who underwent hysteroscopic metroplasty, 81 percent subsequently reported a term pregnancy [19].

Endometrial ablation — Endometrial ablation refers to a procedure in which the lining of the uterus is destroyed to control abnormal uterine bleeding that is not related to malignancy. Standard technique utilizes the operative hysteroscope and an additional energy source, such as a laser or a monopolar or bipolar radiofrequency (RF) generator, and the surgeon looks directly into the uterine cavity while doing the ablation. Global endometrial ablation refers to a host of new technologies that do not require an operative hysteroscope and are often performed blindly. (See "Endometrial ablation").

Lysis of adhesions — Intrauterine adhesions (Asherman syndrome) are most commonly caused by infection or iatrogenic uterine trauma, most commonly related to postpartum curettage. The diagnosis should be suspected in women with a typical history who develop amenorrhea or oligomenorrhea unresponsive to hormonal therapy. Although HSG can confirm the diagnosis, hysteroscopy enables the physician both to diagnose and remove intrauterine adhesions using hysteroscopic scissors under direct visualization. This decreases the probability of trauma to the surrounding endometrium compared to blind adhesiolysis.

Care must be taken during cervical dilation in women with severe occlusion of the uterine cavity because it is easy to create false passages and perforate the uterus. Concurrent ultrasonography can help define the junction between the internal os and the intrauterine cavity.

The procedure is begun by placing the hysteroscope at the internal os and lysing adhesions with sharp dissection. We prefer to use a small, rigid scissors. Careful dissection is continued until the entire uterine cavity is free of adhesions. The procedure is followed by long-term estrogen administration to stimulate regrowth of endometrial tissue.

Approximately 90 percent of patients can expect to have normal menses restored and approximately 80 percent will achieve a term pregnancy. One study of 187 women noted obstetric outcome was related to the degree of occlusion of the uterine cavity [20]. Term pregnancy was achieved in 81 percent of women with mild occlusive disease, but only 32 percent of those with severe occlusion.

Transcervical tuboplasty — Proximal tubal occlusion can be caused by infection, salpingitis isthmica nodosum, intraluminal debris, tubal spasm, ectopic pregnancy, tubal ligation, and endometriosis. Proximal tubal occlusion is typically diagnosed by HSG during an infertility evaluation. However, HSG may not differentiate tubocornual spasm from a mechanical obstruction and tends to overdiagnose proximal tubal occlusion [21]. Selective salpingography, using fluoroscopic guidance to selectively cannulate and inject dye into a fallopian tube, is useful and may obviate the need for surgery in some women [22].

If proximal tubal occlusion is confirmed, hysteroscopy with concurrent laparoscopy can be used to perform transcervical tuboplasty. Laparoscopy is used to document the condition of the distal fallopian tube. Transcervical tuboplasty is more cost-effective than either transabdominal tuboplasty or in vitro fertilization.

Using a single-port operating hysteroscope, either a 3-French coaxial catheter and guidewire or a balloon catheter can be inserted under direct visualization into the tubal ostia to establish tubal patency. Dye can be injected through the catheter to confirm patency. There are no controlled data to support the use of selective tubal cannulation for proximal tubal occlusion. In a multicenter study on balloon tuboplasty for proximal tubal occlusion, 92 percent of 77 women had successful recanalization of at least one tube, and 23 women subsequently conceived [23].

Sterilization — The Essure permanent birth control procedure is a minimally invasive hysteroscopic technique for permanent tubal occlusion. A tiny coil mechanism is inserted into the fallopian tube hysteroscopically under local anesthesia [24,25]. The device appears to induce fibrosis, which occludes the tubes over a three month period. In clinical studies including several hundred women, effectiveness at 2 years was 99.8 percent [26]; data beyond 2 years is not available. Patients must use alternative contraception until a hysterosalpingogram performed three months postoperatively confirms tubal occlusion. Only 440 of 518 women (85 percent) in one clinical study had successful bilateral occlusion at the first procedure; success was ultimately achieved in 449 after two procedures [27]. Reasons for failure included inability to visualize/access the tubal ostia, expulsion, perforation, and malplacement [27].

It is recommended that the procedure be performed in the follicular phase, shortly after menses, when the endometrium is thin and pregnancy improbable. Nonsteroidal premedication is also recommended to reduce tubal spasm, as well as analgesia. The average in office procedure time is 36 minutes [26]. Complications are uncommon and include vasovagal reaction, vomiting, hypervolemia, vaginal bleeding, and perforation.

Because the inserted coil can conduct electricity, electrosurgical procedures in the vicinity of the device should be avoided. Contact with the coil can cause thermal injury. Containdications to use include pregnancy within six weeks, active or recent pelvic infection, nickel allergy, and some uterine anomalies.

POSTOPERATIVE CARE — The woman should remain recumbent for a few minutes. Referred shoulder pain can occur when carbon dioxide is used, but typically resolves within 10 minutes. She may resume normal activities (eg, work, exercise, intercourse) after the procedure, and should contact the surgeon if she develops fever, foul discharge, heavy bleeding, or persistent pain.

COMPLICATIONS — Complications from hysteroscopy are rare (less than 1 percent for office procedures), but can be serious, and even fatal. In the systematic review of over 26,000 diagnostic procedures discussed above (see "Diagnostic hysteroscopy" above), only eight serious complications were reported (five perforations, 1 infection, 2 medical complications), although complication data was not consistently published [4].

Fluid overload — Complications related to distending media vary according to the media used [28]. Absorption of large volumes of electrolyte-free, low-viscosity fluid may result in volume overload with water intoxication, pulmonary edema, hyponatremia, hypo-osmolarity, and cerebral edema. Absorption of dextran-70 may cause volume overload due to the oncotic effect of intravascular dextran as well as anaphylaxis and coagulation disorders.

The key to decreasing the likelihood of complications associated with dextran 70 is to restrict the volume used in any procedure to less than 500 mL, although complications can still occur with lower volumes of dextran [29]. Most complications may be avoided by closely monitoring fluid balance intraoperatively and keeping intrauterine pressure low with judicious use of diuretics and correction of electrolyte imbalance if problems occur. Anesthesiologists need to keep intravenous fluids at a minimum.

Fluids for hysteroscopy should be warmed, as significant hypothermia can occur, potentiating the risk of acidemia and cardiac arrthymias. Fluid overload and hyponatremia are complications of low-viscosity, sodium-free fluids. A fluid deficit of greater than 1,000 mL in a young, healthy woman poses a significant risk of fluid overload. In the older woman, or those with a history of cardiovascular compromise, a 750 mL deficit is significant. The procedure should be discontinued when the fluid deficit reaches these limits and the serum electrolytes should be assessed. A rapid decrease in serum sodium concentration can result in generalized cerebral edema, seizures, and death. Diuretics and intravenous fluid restriction can be used to treat hyponatremia and fluid overload.

Electrosurgical injury — An injury can result from thermal effects of either electrical or laser energy. Injuries to the uterine cavity as well as bowel, urinary bladder, and large pelvic vessels, have been described. In particular, a significant risk of bowel injury has been reported from hysteroscopic coagulation of the tubal cornua for sterilization [30]. One must be cautious when coagulating in the tubal recesses.

These complication can be avoided by always moving the electrical instrument when activated. because the temperature of the uterine serosal surface does not rise appreciably as long as the roller ball is not held stationary during coagulation [31].

Bleeding — Potential sources of intraoperative bleeding include lacerations due to cervical manipulation and uterine perforation. Bleeding from cervical lacerations that is recognized at surgery can be controlled using electrocautery or sutures. Postoperative bleeding can be treated by placing a Foley catheter in the uterine cavity and then distending the bulb with 15 to 30 mL of water. In one series of 216 resectoscope procedures, four women (1.9 percent) developed postoperative uterine bleeding and were successfully treated with this procedure [32].

Embolism — Carbon dioxide or air embolism can cause cardiovascular collapse. Dyspnea is the most common symptom; othe signs and symptoms are listed in Table 1 (show table 1). Supportive care (eg, the use of mechanical ventilation, vasopressors, volume resuscitation as indicated) is the cornerstone of management, but several active measures may also be helpful. (See "Air embolism").

Vasovagal reactions — Vasovagal syncope (also called neurocardiogenic syncope) is usually, but not always, associated with a prodrome of dizziness, nausea, pallor or diaphoresis. Stopping the procedure, assumption of the supine position with legs raised or Trendelenburg position at the onset of such symptoms, and fluid administration can be helpful. Some patients may require atropine or smelling salts (ie, aromatic ammonia spirit).

Dissemination of tumor — Hysteroscopy in women with endometrial cancer may disseminate tumor cells into the peritoneal cavity [33-35]. Positive peritoneal washings mean the surgical stage will be at least IIIA. (See "Clinical features and diagnosis of endometrial cancer"). However, the clinical significance of this finding is not known as transport of these cells does not necessarily result in implantation and persistence. There are no studies comparing long-term outcome in women with or without hysteroscopy prior to treatment of endometrial cancer.

Infection — The risk of infection after operative hysteroscopy is low, thus prophylactic antibiotics are not routinely administered. One series of 2116 operative hysteroscopies reported 18 (0.85 percent) endometritis infections and 12 (0.57 percent) urinary infections postoperatively [36].

PROCEDURE FAILURES — There are several reasons for hysteroscopic failure. In the office setting, pain, cervical stenosis and other anatomic factors are the most common reasons for terminating a procedure. In inpatients, inadequate visualization is most often due to bleeding, debris, or anatomic factors. Sometimes a procedure will be progressing without difficulty, but will need to be stopped prematurely because of an excessive fluid deficit or uterine perforation (which precludes adequate uterine distention). Women with uterine synechiae often experience recurrence of their adhesions after hysteroscopic adhesiolysis and require reoperation [37]. In addition, successful transcervical tuboplasty may be followed by recurrent tubal obstruction and menorrhagia may not be satisfactorily controlled by endometrial ablation. Although the author does not advocate repeat transcervical tuboplasty for failed procedures, women with failed endometrial ablations and less than adequate resection of submucous leiomyomas or uterine septa are candidates for repeat procedures, if indicated.

In the systematic review of over 26,000 procedures discussed above (see "Diagnostic hysteroscopy" above), the overall rate of failure was 3.6 percent, and was similar in ambulatory and hospitalized patients and pre- and postmenopausal women [4].