Hysteroscopic mechanical morcellators have gained popularity given their ease of use. Consequently, the resectoscope loop is being used less frequently, which has resulted in less familiarity with this device. The resectoscope loop, however, not only is cost effective but also allows for multiple distinct advantages, such as cold loop dissection of myomas and the ability to obtain electrosurgical hemostasis during operative hysteroscopy.
In this article, we review the basics of electrosurgical principles, compare outcomes associated with monopolar and bipolar resectoscopes, and discuss tips and tricks for optimizing surgical techniques when using the resectoscope loop for hysteroscopic myomectomy.
Evolution of hysteroscopy
The term hysteroscopy comes from the Greek words hystera, for uterus, and skopeo, meaning “to see.” The idea to investigate the uterus dates back to the year 1000 when physicians used a mirror with light to peer into the vaginal vault.
The first known successful hysteroscopy occurred in 1869 when Pantaleoni used an endoscope with a light source to identify uterine polyps in a 60-year-old woman with abnormal uterine bleeding. In 1898, Simon Duplay and Spiro Clado published the first textbook on hysteroscopy in which they described several models of hysteroscopic instruments and techniques.
In the 1950s, Harold Horace Hopkins and Karl Storz modified the shape and length of lenses within the endoscope by substituting longer cylindrical lenses for the old spherical lenses; this permitted improved image brightness and sharpness as well as a smaller diameter of the hysteroscope. Between the 1970s and 1980s, technological improvements allowed for the creation of practical and usable hysteroscopic instruments such as the resectoscope. The resectoscope, originally used in urology for transurethral resection of the prostate, was modified for hysteroscopy by incorporating the use of electrosurgical currents to aid in procedures.
Over the past few decades, continued refinements in technology have improved visualization and surgical techniques. For example, image clarity has been markedly improved, and narrow hysteroscope diameters, as small as 3 to 5 mm, require minimal to no cervical dilation.
Monopolar and bipolar resectoscopes
Electrosurgery is the application of an alternating electrical current to tissue to achieve the clinical effects of surgical cutting or hemostasis via cell vaporization or coagulation. Current runs from the electrosurgical unit (ESU) to the active electrode of the surgical instrument, then goes from the active electrode through the patient’s tissue to the return electrode, and then travels back to the ESU. This flow of current creates an electrical circuit (FIGURE).
All electrosurgical devices have an active and a return electrode. The difference between monopolar and bipolar resectoscope devices lies in how the resectoscope loop is constructed. Bipolar resectoscope loops house the active and return electrodes on the same tip of the surgical device, which limits how much of the current flows through the patient. Alternatively, monopolar resectoscopes have only the active electrode on the tip of the device and the return electrode is off the surgical field, so the current flows through more of the patient. On monopolar electrosurgical devices, the current runs from the ESU to the active electrode (monopolar loop), which is then applied to tissue to produce the desired tissue effect. The current then travels via a path of least resistance from the surgical field through the patient to the return electrode, which is usually placed on the patient’s thigh, and then back to the ESU. The return electrode is often referred to as the grounding pad.
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