Background
Hysteroscopy is the process of viewing and operating in the endometrial cavity from a transcervical approach. The basic hysteroscope is a long, narrow telescope connected to a light source to illuminate the area to be visualized. With a patient in the lithotomy position, the cervix is visualized by placing a speculum in the vagina. The distal end of the telescope is passed into a dilated cervical canal, and, under direct visualization, the instrument is advanced into the uterine cavity. A camera is commonly attached to the proximal end of the hysteroscope to broadcast the image onto a large video screen. Other common modifications are inflow and outflow tracts included in the shaft of the telescope for fluids. Media, such as sodium chloride solution, can be pumped through a hysteroscope to distend the endometrial cavity, enabling visualization and operation in an enlarged area.
Hysteroscopy is a minimally invasive intervention that can be used to diagnose and treat many intrauterine and endocervical problems. Hysteroscopic polypectomy, myomectomy, and endometrial ablation are just a few of the commonly performed procedures. Given their safety and efficacy, diagnostic and operative hysteroscopy have become standards in gynecologic practice.
Equipment
Hysteroscopes
The telescope consists of 3 parts: the eyepiece, the barrel, and the objective lens. The focal length and angle of the distal tip of the instrument are important for visualization (as are the fiberoptics of the light source).
Angle options include 0°, 12°, 15°, 25°, 30°, and 70°. A 0° hysteroscope provides a panoramic view, whereas an angled one might improve the view of the ostia in an abnormally shaped cavity.
Hysteroscopes are available in different styles, including rigid and flexible (used most commonly in clinical settings) hysteroscopes, contact hysteroscopes, and microcolpohysteroscopes. The diameter of each instrument varies and is an important consideration. The requirement of a sheath for input-outflow of distention media increases the size of the hysteroscope.
Rigid hysteroscopes
Rigid hysteroscopes are the most commonly used instruments. Their wide range of diameters allows for in-office and complex operating-room procedures. Of the narrow options (3-5 mm in diameter), the 4-mm scope offers the sharpest and clearest view. It accommodates surgical instruments but is small enough to require minimal cervical dilation. In addition, patients tolerate this instrument well with only paracervical block anesthesia.
Rigid scopes larger than 5 mm in diameter (commonly 8-10 mm) require increased cervical dilation for insertion. Therefore, they are most frequently used in the operating room with intravenous (IV) sedation or general anesthesia. Large instruments include an outer sheath to introduce and remove media and to provide ports to accommodate large and varied surgical instruments.
Flexible hysteroscopes
The flexible hysteroscope is most commonly used for office hysteroscopy. It is notable for its flexibility, with a tip that deflects over a range of 120-160°. Its most appropriate use is to accommodate the irregularly shaped uterus and to navigate around intrauterine lesions. It is also used for diagnostic and operative procedures.
During insertion, the flexible contour accommodates to the cervix more easily than does a rigid scope of a similarly small diameter. The view was initially described as having a ground-glass quality, which was markedly less desirable than the view obtained with rigid scopes.[1] New, digitally enhanced scopes now offer similar image quality to a rigid hysteroscope lens.
Light source
Each hysteroscope is attached to an internal or external light source for illumination at the distal tip. Energy sources include tungsten, metal halide, and xenon. A xenon light source with a liquid cable is considered the superior option.[2, 3]
Surgical instruments
Surgical instruments are available in both rigid and flexible forms to be inserted through the operating channels of the scopes. Examples of surgical instruments and their uses are listed below:
- Scissors - To incise a septum, excise a polyp, or lyse synechiae
- Biopsy forceps - To perform directed biopsy for pathologic review
- Grasping instruments - To remove foreign bodies
- Roller ball, barrel, or ellipsoid - To perform endometrial ablation and/or desiccation (This instrument is used with a resectoscope.)
- Loop electrode - To resect a fibroid or polyp or endometrium (This instrument is used with a resectoscope.)
- Scalpel - To cut or coagulate tissue, with high power density at its tip (This instrument is used with a resectoscope.)
- Vaporizing electrodes – To destroy endometrial polyps, fibroids, intrauterine adhesions, and septa; also used for endometrial ablation (This instrument is used with a resectoscope.)
- Morcellator – To cut and remove endometrial polyps or fibroids
Improvements in hysteroscope design have improved the effectiveness of the inflow-outflow channels and of specific operating instruments. For example, the Chip E-Vac System (Richard Wolf Medical Instruments Corporation, Vernon Hill, Ill) incorporates a suction channel and a pump to aid in removing chips of tissue during resection. This feature improves visibility and may decrease time otherwise spent emptying the pieces from the endometrial cavity.
Another instrument in the forefront is a hysteroscopic morcellator (Smith & Nephew, Inc, Andover, Mass), which may reduce myomectomy and polypectomy time by morcellating and removing tissue in 1 movement under direct visualization. It requires cervical dilation to 9 mm. A new hysteroscopic morcellating system called MyoSure (Interlace Medical, Inc, Framingham, Mass) is reported to work just as well, removing submucosal fibroids up to 3 cm in diameter, with a unit that only requires cervical dilation to 6 mm. This smaller diameter suggests it may be used in an office setting.
Energy sources and uses
Monopolar and bipolar electricity, as well as laser energy, all have uses in hysteroscopy.
Monopolar cautery
The resectoscope is a specialized instrument often used with a monopolar, double-armed electrode and a trigger device for use in hypotonic, nonconductive media, such as glycine. It cuts and coagulates tissue by means of contact desiccation with resistive heating.[4] The depth of thermal damage is based on several factors: endometrial thickness; speed, pressure, and duration of contact during motion; and power setting.[5, 4]
A thin electrode can cut tissue, whereas one with a large surface area, such as a ball or barrel, is best suited for coagulation.[6]
Bipolar cautery
The VersaPoint system (Gynecare, Inc, Somerville, NJ), uses bipolar circuitry for electrosurgery, which can be performed in isotonic conductive media. This system includes a spring tip for hemostatic vaporization of large areas, a ball tip for precise vaporization, and a twizzle tip for hemostatic resection and morcellation of tissue. There is also a cutting loop similar to traditional resectoscopy.[4]
Bipolar resectoscopes have been designed by both Karl Storz (Tuttlingen, Germany) and Richard Wolf Medical Instruments Corporation (Vernon Hill, Ill). The latter has developed the Princess (Petite Resectoscope Including E-Line and S-Line Systems), a 7 mm resectoscope — the smallest bipolar resectoscope available. In addition, the Chip E-Vac System (Richard Wolf Medical Instruments Corporation, Vernon Hill, Ill) can be used with bipolar and monopolar energy.
Laser techniques
Several fiberoptic lasers are available for gynecologic use, including potassium-titanyl-phosphate (KTP), argon, and Nd:YAG lasers. They all have different wavelengths, though the KTP and argon lasers have similar properties.
Media
The use of media is critical for panoramic inspection of the uterine cavity. The medium opens the potential space of the otherwise narrow uterine cavity. Intrauterine pressures needed to adequately view the endometrium are proportional to the muscle tone and thickness of the uterus. The refractive index of each medium affects magnification and visualization of the endometrium.
Gases
Carbon dioxide (CO2) is rapidly absorbed and easily cleared from the body by respiration. The refractory index of CO2 is 1.0, which allows for excellent clarity and widens the field of view at low magnification. The gas easily flows through narrow channels in small-diameter scopes, making it useful for office-based diagnostic hysteroscopy. However, this method offers no way to clear blood from the scope.
With CO2, a hysteroscopic insufflator is required to regulate flow and limit maximal intrauterine pressure. (Note that laparoscopic insufflators are not safe.) A flow rate to 40-60 mL/min at a maximum pressure of 100 mm Hg is generally accepted as safe. Pressures and rates higher than this can result in cardiac arrhythmias, embolism, and arrest.[2]
Fluids
The advantage of fluid over gas is the symmetric distention of the uterus with fluid and its effective ability to flush blood, mucus, bubbles, and small tissue fragments out of the visual field. Both low-viscosity and high-viscosity fluid media can be used for distention. A pressure of 75 mm Hg is usually adequate for uterine distention; rarely is more than 100 mm Hg required, and pressures higher than this can increase the risk of intravasation of medium.[7]
Various delivery systems are designed to suit the many media used for uterine distention and to accurately record volumes of inflow and outflow. This recording is important because fluid can leave the uterus by means of intended efflux systems, cervical or tubal leakage, or intravasation. Preventing excess absorption of hypotonic fluids is essential for patient safety. The simplest delivery system is a syringe that most often is used with high-viscosity Dextran 70. Hanging, gravity-fed containers to deliver low-viscosity fluids can be raised or compressed with a cuff; however, these can be unreliable in estimating intrauterine pressures. Pumps are available to monitor pressure and volume for low-viscosity media. Media then usually flows into the uterine cavity through an inner sheath around the hysteroscope. A perforated outer sheath is used for collection or efflux of media. This design creates laminar flow, which keeps the visual field clear.[1]
As noted above, new, sophisticated efflux mechanisms have been designed to improve the clearance of both blood and particulate matter from the operating space. Closed systems actively return fluid to a pump reservoir, whereas open systems allow free flow of the medium out the cervix into a collection bag for volume monitoring.
0.9% sodium chloride solution and lactated Ringer solution
Normal sodium chloride solution and lactated ringer solution are isotonic, conductive, low-viscosity fluids that can be used for diagnostic hysteroscopy and for limited operative procedures. Surgical procedures using mechanical, laser, monopolar (only with the ERA sleeve or Opera Star systems), and bipolar energy (VersaPoint system) are safe (see Surgical instruments and Energy sources and uses above).
Two major disadvantages associated with these solutions include (1) their miscibility with blood, which obscures visibility with bleeding, leading to the need for increased volumes to clear the operative field, and (2) their excellent conductivity, which precludes procedures that use standard monopolar electrosurgery.
5% Mannitol, 3% sorbitol, and 1.5% glycine
The hypotonic, nonconductive, low-viscosity fluids 5% mannitol, 3% sorbitol, and 1.5% glycine improve visualization when bleeding occurs. They can be used in diagnostic as well as operative hysteroscopy. (Note that 5% mannitol can be used only with monopolar operative procedures.)
All impose a risk of volume overload and hyponatremia from intravascular absorption (particularly > 2 L). Therefore, careful fluid monitoring is required during their use. When intravasation of 5% mannitol occurs, it stays in the extracellular compartment; treatment of this condition is discontinuing the procedure and administering diuretics.[7] 3% sorbitol is broken down into fructose and glucose and therefore has an added risk of hyperglycemia when absorbed in excess. Use 1.5% glycine with caution in patients with impaired hepatic function because glycine is metabolized to ammonia.
Dextran 70
The only high-viscosity medium available, Dextran 70 (Hyskon; Pharmacia Laboratories, Piscataway, NJ) is a nonelectrolytic, nonconductive fluid that can be used in all types of procedures. It is immiscible with blood and minimally leaks through the cervix and tubes, allowing for excellent visibility during surgical procedures.
Like the other nonelectrolytic fluids, however, prevent absorption of more than 500 mL to avoid fluid overload. With each 100 mL of Dextran 70 absorbed, the intravascular volume increases by 800 mL.[7, 8] Allergic reactions and anaphylaxis, fluid overload, disseminated intravascular coagulopathy, and destruction of instruments are adverse effects of this medium.
History of the Procedure
The development of hysteroscopy is rooted in the work of Pantaleoni, who first reported uterine endoscopy in 1869.[7] However, at that time, instrumentation was elementary, and expansion of the uterine cavity was insufficient. In 1925, Rubin first used CO2 to distend the uterus.[7] Around the same time, Gauss was experimenting with the use of fluids to achieve uterine expansion.
Hysteroscopy did not become popular until the 1970s, when technology afforded more practical and usable instruments than before (see Hysteroscopes above). The use of liquid distention media became routine by the 1980s, and many new hysteroscopic procedures, including endometrial ablation, were developed.[7] Initially used by urologists for transurethral resection of the prostate, the resectoscope was modified for hysteroscopic procedures, allowing for resection of intrauterine pathology with monopolar cautery. By the mid-1980s, hysteroscopic procedures had nearly replaced dilation and curettage (D&C) for diagnosing intrauterine pathology.[9]
Over the past few decades, refinements in optic and fiberoptic technology and inventions of new surgical accessories have dramatically improved visual resolution and surgical techniques in hysteroscopy. Many hysteroscopic procedures have replaced old, invasive techniques. Now, as instruments become smaller than before, office hysteroscopy is replacing operating-room procedures. One of the most recent hysteroscopic procedures approved by the US Food and Drug Administration (FDA) is female sterilization (Essure, Conceptus, Incorporated, Mountain View, Calif), which can be performed in the gynecologist's office. Novel instruments and techniques continue to emerge, and the prospects for improvement seem unlimited.
Indications
Abnormal uterine bleeding
Hysteroscopy has nearly replaced standard D&C for the management of abnormal uterine bleeding (AUB), as it allows for direct visualization and diagnosis of intrauterine abnormalities, and it often offers an opportunity for simultaneous treatment.[10]
To diagnose the cause of AUB, a full workup is required to rule out endocrine or hormonal disorders, benign lesions, premalignant, or malignant pathology. Uterine sampling can be done by means of endometrial biopsy, D&C, or direct visualization with hysteroscopy and specific biopsy procedures. Evaluation of the uterine cavity with sonohysterography or diagnostic hysteroscopy is up to 88% effective in identifying polyps and submucosal fibroids.[11, 12]
Hysteroscopic diagnosis of intracavitary abnormalities in women with AUB carries a sensitivity of 94% and specificity of 89%[13] and compares favorably with the accuracy of saline infusion sonography, which has a reported 95% sensitivity and 88% specificity.[14] Of note, the diagnostic accuracy of hysteroscopy for endometrial cancer is also high with an overall sensitivity of 86.4% and specificity of 99.2%.[15] Some consider MRI useful for evaluating intrauterine pathology, but MRI is a relatively expensive test.[16]
For patients with AUB for whom fertility is not an issue, in whom no endocrine or hormonal cause is isolated, and in whom endometrial atypia or malignancy is ruled out, endometrial ablation has become an acceptable alternative to hysterectomy. In the short term, ablation for a benign disorder results in amenorrhea in approximately 30% of patients.[17, 8, 18] Studies show that approximately 26% of patients have spotting after ablation, 34% have a decreased flow, and 10% have no change or increased symptoms.[8] The same data suggested that the long-term effectiveness of endometrial ablation for menorrhagia or fibroids is 60-90%, with 90% of patients noting an overall decrease in flow and amenorrhea, which occurs in 30-50%.[19]
Reported reoperation rates after endometrial ablation (resectoscope, vaporization or thermal balloon method) have been reported to be as high as 38% at 5 years.[20] Review including only first generation endometrial ablation techniques estimated that 6-20% of women require further surgery for control of menorrhagia after 1-5 years of follow-up.[21] Patients who are taking estrogen still require progesterone for endometrial protection from estrogen-induced endometrial changes.[11]
Infertility
Hysteroscopy is not part of the routine workup for infertility, but when compared with hysterosalpingography, hysteroscopy is equivalent for evaluating the uterine cavity, and it increases accuracy in diagnosing the cause of intrauterine filling defects.[1] In unexplained infertility, hysteroscopy may be performed simultaneously with laparoscopy to evaluate the uterine cavity and cervix.[22]
Intracavitary lesions are implicated as causes of infertility, and their removal may increase fertility. However, literature supporting the significance of this association is scant. Overall, pregnancy rates of 50-78% in previously infertile women have been reported after hysteroscopic polypectomy.[23, 24, 25, 26, 27] Pregnancies were conceived spontaneously or with the use of intrauterine insemination or in vitro fertilization. The only randomized control trial comparing pregnancy rates after polypectomy versus no treatment in infertile women concluded hysteroscopic polypectomy prior to IUI increased the odds of pregnancy, with a relative risk of 2.1 (95% CI, 1.5-2.9). Of note, 65% of the women who were randomized to polypectomy became pregnant prior to the first IUI.[25]
The effect of hysteroscopic polypectomy on IVF also remains unclear. In general, studies have suggested that hysteroscopic removal of lesions < 2 cm does not adversely affect an IVF cycle.[28, 29, 30]
The incidence of myomas in women without another obvious etiology for infertility is small, estimated to be 1-2.4%.[31] The effect of myomas on reproduction is not definitive but it is generally accepted that fibroids causing distortion of the endometrial cavity may adversely influence fertility.[32] Location, size of myomas, and coexisting fertility diagnoses are believed to be major considerations when determining management options.
Surgical management with hysteroscopic myomectomy has been reported to yield pregnancy rates of 16.7-76.9% (mean of 45%) in infertile women.[31, 33] However, no randomized controlled trials examine the effect of hysteroscopic myomectomy on fertility, and pregnancy rate estimates come from retrospective and small prospective studies with large variations in study populations and design. Debate also exists in regard to management of small myomas with minimal uterine cavity distortion.
For patients with recurrent miscarriage and intracavitary fibroids, surgery increases rates of viable pregnancy outcomes.[34]
Myomas may adversely affect outcomes for women undergoing IVF but there again remains no definitive consensus on management of fibroids prior to an IVF attempt. A negative impact of submucosal fibroids on pregnancy rates has been demonstrated in 3 separate meta-analyses.[35, 31, 36] Intramural fibroids have also been reported to have a significant negative influence on pregnancy rates.[37, 36] However, other meta-analyses have not supported the association.[35, 31] Furthermore, a meta-analysis of 2 retrospective studies available in the literature examining hysteroscopic myomectomy suggests that the procedure does not negatively affect pregnancy rates in IVF cycles.[36]
Intrauterine adhesions
Asherman syndrome was identified in 1948 as uterine synechiae.[38] These intrauterine adhesions (IUA) are often associated with amenorrhea or infertility. The prevalence rate of IUAs in the general population is 1.5%, with adhesions noted in up to 30% of women undergoing hysteroscopy following 3 or more spontaneous abortions treated with dilation and curettage.[39] Hysteroscopy is the gold standard used to diagnose and treat these adhesions. Benefits include visually directed lysis. Filmy adhesions are often lysed by distention alone, whereas the dense adhesions often require cutting or excision with blunt, sharp, electrocautery, or laser techniques.[2] Fluoroscopic guidance can also be used to assist in restoration of the uterine cavity.[40]
If the patient's symptoms include abnormal bleeding, hysteroscopic treatment results in an 88-98% return to normal menstrual cycles.[11, 19] If no other infertility issues are present, 79% of treated patients have normal pregnancies (ie, 75% of those with mild disease but only 31% with severe adhesions).[11]
Reformation of adhesions may have a significant impact on the conception rate after hysteroscopic adhesiolysis. Conception rates in women with recurrence of adhesions after initial hysteroscopic adhesiolysis have been found to be significantly lower than in women with demonstration of a normal uterine cavity on second look hysteroscopy (11.8% vs 59.1%). Of consideration, hysteroscopic treatment may also increase the risk of abnormal placentation (eg, accreta, percreta, increta, previa).
Müllerian anomalies
Approximately 1-2% of all women, 4% of infertile women, and 10-15% of patients with recurrent miscarriage have müllerian anomalies. These anomalies range from didelphys to müllerian agenesis. Uterine septum and in utero diethylstilbestrol (DES) exposure are more likely to be associated with miscarriage than is uterus didelphys.[11] Patients with a bicornuate uterus have a >50% live birth rate compared with those with a uterine septum, who have a < 30% live birth rate.[41] Patients with in utero DES exposure are likely to have a T -shaped uterus with corneal restriction bands, pretubal bulges, lower-uterine-segment dilation, and a small and irregular cavity with borders resembling adhesions.[11] Hysteroscopy can be used to confirm but not always to treat these findings.
Septate uterus is the most common structural uterine anomaly, accounting for 35% of anomalies, and is associated with the highest incidence of reproductive failure.[42] The diagnosis of septate uterus is made after excluding the diagnosis of a bicornuate uterus. Once 2 hemicavities are visualized on imaging, the uterine fundus must be evaluated. Evidence of fundal indentation is an indication of bicornuate uterus, whereas, a smooth fundus is present with uterine septum. HSG, transvaginal ultrasonography, 3-dimensional ultrasonography, and MRI have all been used to make an accurate diagnosis but concurrent hysteroscopy and laparoscopy remain the gold standard.[42]
Division of a uterine septum has historically been performed by laparotomy but is now most commonly performed via a hysteroscopic approach. Edstrom reported the first hysteroscopic resection of a septum[1] and Bret and Guillet were the first to recommend incising versus excising the septum.[41] Surgical complications are fewer with the hysteroscopic approach than with other procedures, such as Jones, Strassman, or Tompkins metroplasty.[41] Of patients undergoing hysteroscopic resection for müllerian anomalies, 20% have dysmenorrhea after surgery compared with 50% after abdominal procedures.[41] Rates of term-pregnancy outcomes after hysteroscopic resection are equivalent to those of abdominal metroplasty for uterine septum.[11] Live birth rates after treatment are as high as 80%.[19]
Significant improvements are seen in pregnancy outcomes following hysteroscopic metroplasty in women with recurrent miscarriage. Pregnancy rates have been estimated to increase from 3% prior to surgery to approximately 80% after hysteroscopic correction with a significant decrease in miscarriage rates.[43]
Although, a septate uterus is not a cause for infertility, the literature suggests women with a septate uterus and otherwise unexplained infertility may benefit from metroplasty, but to a more modest extent.[44, 45] In comparison to women with unexplained infertility and a normal uterine cavity, pregnancy rates have been shown to be significantly higher in women with a septum after removal, 20.4% versus 38.6% (after 12 mo of follow-up). Live birth rates of 18.9% versus 34.1% were also reported.[44]
Metroplasty should also be considered for women who plan to undergo IVF.[42] Retrospective review has also indicated that pregnancy outcomes may improve with IVF after the incision of an incomplete septum, but continued investigation is needed.[46]
Polyps and fibroids
Endometrial polyps and fibroids are well known to cause irregular vaginal bleeding. Fibroids are the most common solid pelvic tumor in women, found in 20% of women older than 35 years.[11] Menorrhagia due to symptomatic submucosal fibroids is the most common indication for surgical intervention.[34] Other indications include infertility, dysmenorrhea, and pelvic pain.
Polyps and submucosal fibroids can be definitively diagnosed and effectively treated with hysteroscopy. Diagnosis of endometrial polyps via hysteroscopy is 94% sensitive and 92% specific. For submucosal myomas, diagnostic hysteroscopy is 87% sensitive and 95% specific.[13] Only 16% of treated patients require further surgery.[3]
When AUB is present, polypectomy has been reported to successfully alleviate symptoms 75-100% of the time.[47] Initial hysteroscopy is estimated to successfully remove fibroids in 85-95% of cases, with additional surgery required in approximately 5-15%.[48] Recurrence of symptoms after hysteroscopic myomectomy is most common with large uteri and numerous and deep fibroids.[49, 34]
The advantages of hysteroscopic resection are numerous and include treating irregular bleeding and obtaining tissue diagnosis; for myomectomy, benefits include avoiding laparotomy, uterine incision, and hospital stays. If a fibroid is predominantly submucosal, complete resection is possible. A 2-step procedure is sometimes needed to resect a fibroid that is partially intramural or large.[16]
Some investigators report improved results and decreased adhesion rates after pretreatment with a gonadotropin-releasing hormone (GnRH) agonist or medroxyprogesterone acetate (Depo-Provera) on the day of surgery,[11] while others report no benefit and possibly increased difficulty of surgery.[50] Postoperative use of estrogen decreases adhesion formation.[11, 19]
In patients desiring to maintain fertility, hysteroscopic myomectomy is a reasonable option,[51, 52] and minimal cauterization should be used to decrease damage to otherwise healthy endometrium.
Sterilization
Irreversible tubal sterilization can be accomplished transcervically with the Essure contraceptive tubal occlusion device and delivery system (Conceptus Inc, Mountain View, Calif). The procedure is quick, with a total procedure time averaging 35 minutes (Conceptus Inc). More recent studies report the total procedure to actually be less than 15 minutes.[53] There is no need for abdominal incisions, recovery time is rapid, and successful bilateral placement at first attempt ranges from 83-94.1%. A second attempt at placement may be needed, increasing successful placement to 96.7%.[53] Overall, the procedure carries a 4-year effectiveness rate of 99.8% (Conceptus Inc).
Good visualization of the tubal ostia, placement during the proliferative phase of the menstrual cycle, and NSAID premedication have all been significantly associated with successful placement.[54, 55, 53]
Confirmation of tissue ingrowth by further imaging is required 3 months after the procedure. HSG is currently the accepted and recommend imaging modality, but transvaginal ultrasonography with or without contrast infusion has also been proposed.[56, 57, 58] A 2011 study of 118 women who had successful bilateral Essure placement found contrast infusion sonography to be a safe and accurate confirmation test.[59] Bilateral tubal occlusion is seen at 3 months in 92% of women after the first attempt at placement.[60] The procedure can be repeated a second time to ultimately achieve occlusion.
Additional contraceptive control is required until placement and tubal occlusion are confirmed. Pregnancy can occur after the procedure with most reported pregnancies occurring in women with inadequate follow-up.[61] Additional explanations include preprocedure pregnancy and misinterpretation of the HSG.
Adverse events include expulsion of the microinsert, tubal perforation, and delayed tubal occlusion. Procedural side effects include a vasovagal response, cramping, dizziness, nausea, hypervolemia, and vaginal spotting.
Most importantly, the procedure is irreversible and should not be performed in women with uncertainly regarding desire for future fertility.
A recently approved procedure, called Adiana, uses radiofrequency energy within the tubes, followed by insertion of a polymer matrix to promote scarring. Compared to the Essure procedure, no portion of the device is left within the uterine cavity. Initial failure rates seem higher than Essure at 4.9%, but more clinical studies are needed to confirm.
Proximal tubal obstruction
This diagnosis is difficult to make and is most often suggested by the failure of contrast to enter the fallopian tube on HSG. It may be due to infection, intraluminal debris, salpingitis isthmica nodosum, or endometriosis. Many cases may simply be due to spasm.[11] In theory, repair of proximal disease and removal of scar tissue is beneficial, and cannulation of the tubes can be performed at the same time.[19] Up to 85% of occlusions can be treated with cannulation, but reocclusion occurs in approximately one third of cases.[62] Tubal perforation is rare but could lead to further tubal pathology. No controlled studies have been conducted to support the efficacy of hysteroscopic treatment of proximal tubal obstruction for infertility.
Intrauterine devices
Hysteroscopy can be applied to remove an intrauterine device (IUD) under direct visualization after sonography-guided retrieval fails.[3]
Relevant Anatomy
For any hysteroscopic procedure, the surgeon must understand the thickness of the uterine wall. This knowledge allows the surgeon to manipulate the surgery on the basis of the area of the uterus where he or she is operating. The table lists the wall thicknesses for each area of the uterus. Remember that the uterus is longer and thicker in reproductive-aged women than in postmenopausal women.
Table. Thickness of the Uterine Wall (Open Table in a new window)
| Location | Mean, mm | Range, mm |
| Anterior wall | 22.5 | 17-25 |
| Posterior wall | 21 | 15-25 |
| Fundus | 19.5 | 15-22 |
| Isthmus | 10 | 8-12 |
| Corpus | 5.5 | 4-7 |
Contraindications
In general, hysteroscopy is avoided in patients with the following findings:
- Active cervical or uterine infection
- A large uterine cavity, ie, longer than 10 cm in length (clinically similar to a 12-wk pregnant uterus) (However, this number is variable and often depends on the patient's habitus.)
- Severe medical conditions precluding surgery
- Pregnancy
Concerns and contraindications for hysteroscopy depend on the procedure planned. For endometrial ablation, considerations include a desire for future fertility, atypical endometrial hyperplasia or endometrial cancer, and undiagnosed abnormal bleeding. Polypectomy and myomectomy, issues include transmural lesions, use of hypotonic media in patients with hyponatremia, use of glycine in patients with liver disease, and use of sorbitol in patients with severe diabetes. In addition, if the uterus is deeper than 12 cm, the cavity may not distend appropriately.[63] If lesions are larger than 2 cm, patients must be counseled about possibility of a staged procedure, increased fluid deficit, and blood loss.
Contraindications to transcervical sterilization with Essure include current pregnancy or pregnancy within 6 weeks of the scheduled procedure, current or recent lower pelvic infection, allergy to contrast, hypersensitivity to nickel, or patients in whom only one microinsert can be placed (tubal occlusion or uterine abnormalities impeding proper visualization).
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| Location | Mean, mm | Range, mm |
| Anterior wall | 22.5 | 17-25 |
| Posterior wall | 21 | 15-25 |
| Fundus | 19.5 | 15-22 |
| Isthmus | 10 | 8-12 |
| Corpus | 5.5 | 4-7 |

