By Carla Roberts, M.D., Ph.D.
Hysteroscopy is the inspection of the uterine cavity by endoscopy with access through the cervix. It allows for the diagnosis of intrauterine pathology and serves as a method for surgical intervention, also called operative hysteroscopy.
Although the first reported uterine endoscopy was in 1869, the modern-day hysteroscopy did not become popular until the 1970s, when technology yielded more practical and usable instruments. The use of liquid distention media became routine by the 1980s, and many new hysteroscopic procedures, including endometrial ablation, were developed.
By the mid-1980s, hysteroscopic procedures had nearly replaced dilation and curettage (D&C) for diagnosing intrauterine pathology. They are now routinely used for diagnosis and treatment for abnormal bleeding, infertility evaluation, proximal tubal cannulation, transcervical sterilization, difficult removal of IUDs, intrauterine polyps, submucosal myomas, intrauterine adhesions and correction of müllerian anomalies.
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. Many hysteroscopic procedures have replaced old, invasive techniques. As instruments become smaller, office hysteroscopy is replacing operating-room procedures. One of the most recent hysteroscopic procedures approved by the U.S. Food and Drug Administration (FDA) is female sterilization (Essure, Conceptus, Incorporated, Mountain View, Calif), which can be performed in the gynecologist’s office.
Hysteroscopes and Instruments
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). If not a solitary unit, a sheath is required to allow for inflow and outflow of distension media. 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.
Rigid hysteroscopes are the most common, and they are available in a wide range of diameters for both 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 7-10 mm) require increased cervical dilation for insertion. Therefore, they are most frequently used in the operating room with intravenous sedation or general anesthesia. Large instruments include an outer sheath to introduce and remove media and to provide ports to accommodate surgical instruments. The most widely used surgical instruments include scissors, biopsy forceps, graspers, rollerball, loop electrode, vaporizing electrode and the morcellator.
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 a rigid scope of a similarly small diameter.
Recent improvements in specific operating instruments for the hysteroscope incorporates a suction channel and a pump to aid in removing pieces of tissue during resection. This improves visibility and decreases time spent emptying the pieces from the endometrial cavity. Another recently available instrument is a hysteroscopic morcellator, which may reduce myomectomy and polypectomy time by morcellating and removing tissue in one movement under direct visualization. These come in a variety of diameters from 6 to 9 mm. While these require cervical dilation, the smaller diameter morcellators may be useful in the office setting.
A variety of energy sources have been employed with the hysteroscopic technique, including monopolar and bipolar electricity as well as fiber optic lasers including potassium-titanyl-phosphate (KTP), argon, and Nd:YAG lasers. They all have different wavelengths, though the KTP and argon lasers have similar properties.
Table 1 compares the various types of media used to distend the uterine cavity, aid in the visualization of intrauterine pathology and provide an appropriate operative field. There are pros and cons to each type.
Pre-Operative Evaluation. Appropriate procedure should be proceeded by accurate history taking, physical examination, and careful workup of the suspected pathology. In preparation for hysteroscopic procedures, the following may be useful: CBC, electrolytes, β-hCG, Pap smear, cervical cultures, endometrial biopsy and imaging such as a hysterosalpingogram (HSG) or CT/MRI.
Antibiotic prophylaxis is not indicated unless the patient has clinically significant valvular disease or a history of tubal occlusion due to pelvic inflammatory disease.
Office Hysterosocpy. Office hysteroscopy offers many benefits and is becoming more acceptable among patients and gynecologists for both diagnostic and operative procedures. Despite clear advantages, many gynecologists remain hesitant to perform in-office procedures out of fear that the patient, who is generally awake, will experience significant discomfort.
The success of diagnostic and operative hysteroscopic procedures with minimal and acceptable levels of patient discomfort in the office depends, therefore, on multiple factors. Procedural factors affecting the outcome of hysteroscopy include the size of the instrument used, the type and length of the procedure, the use of preprocedure anesthesia or analgesia, and a vaginoscopic approach.
The skill of the surgeon also affects the hysteroscopic experience and outcome. In addition, patient variables such as menopausal status, anatomic distortion (eg, cervical stenosis) and anxiety may adversely affect the patient’s experience.
Future Uses of Hysteroscopy
In 1869, Pantaleoni used a modified cystocope lit with reflected candlelight to examine the uterine cavity of a patient with post menopausal bleeding. Although Pantaleoni blindly used silver nitrate to cauterize the observed bleeding polyps, the ability to treat intrauterine pathology by direct visualization has been ever expanding.
Since that time, the technology surrounding hysteroscopic surgery has continued to expand to meet both physicians’ and patients’ demands for safe, cost-effective and minimally invasive treatments. We can expect to see smaller and smaller instruments with improved visualization to enable more procedures to be done comfortably in the office setting.
In the future, combining hysteroscopy with tissue sampling of the fallopian tubes to test for abnormal pathology may revolutionize ovarian cancer prevention. To be able to do this in an office setting with minimal to no anesthesia would be a development that is beneficial to all of our female patients.