Video Transcript: Intraoperative Vasopressin Injection During Hysteroscopic Myomectomy
The objective of this video is to review techniques to help troubleshoot difficult hysteroscopic myoma resections and demonstrate the use of intraoperative hysteroscopic vasopressin injection to secure hemostasis at the time of myomectomy via a hysteroscopic intrauterine tissue removal device. The case presented is that of a 40-year-old woman with heavy and irregular menstrual bleeding. Transvaginal ultrasound revealed a 3cm to 4cm submucosal fibroid. She has consented for hysteroscopy and myomectomy.
A 6.25mm outer sheath, 0-degree hysteroscope was introduced through the cervix after dilatation. Examining the uterine cavity reveals a large 4cm anterior fibroid, grade 0, as the stalk can be visualized. The myoma encompasses close to the entirety of the uterine cavity. The decision is made to go ahead with the procedure as booked.
The hysteroscopic intrauterine tissue removal device is positioned, and resection of the anterior fibroid is started. The device uses normal saline as a distension medium due to its many advantages over high viscosity medium. The main disadvantage to using normal saline is that the blood is not immiscible. Viewing from far away leads to a cloudy field, as even small amounts of blood mix with the isotonic fluid. In contrast, high viscosity distending media allows blood to appear to drip, as the blood is immiscible in such media.
A method to improve visualization while using normal saline is the flow-by technique. Here you can see that the operative field has become obstructed with blood and tissue. To improve visualization, the flow-by technique is illustrated. The hysteroscope is brought close to the pathology to let high-flow normal saline pass by the tissue and clear the field. The flow-by technique allows for the operative field to be cleared and for resection to continue on the anterior fibroid. The device is moved side-by-side systematically to resect the myoma.
Hysteroscopic myomectomy is the ideal procedure for patients with symptomatic submucosal fibroids. It is safe, cost-effective and has high patient satisfaction. However, it is an operative challenge to achieve complete resection while avoiding complications, including cervical injury, uterine perforation, excessive fluid absorption and bleeding. In order to reduce intraoperative blood loss and improve visual clarity, Vasopressin may be used. There are reports that injection of dilute Vasopressin into myomas preoperatively can reduce bleeding as well as systemic fluid absorption. Vasopressin acts by constricting the smooth muscle in the myometrium and the walls of the capillaries, small arterioles and venules.
As you can see, the majority of the fibroid appears to be removed. Only the base of the stalk remains. In efforts to resect the base, brisk bleeding is encountered. The flow-by technique is attempted. The scope is brought close to the bleeding to let high-flow saline clear the field. However, the bleeding is too brisk. The decision is made to inject Vasopressin into the myometrium in an attempt to obtain hemostasis. The hysteroscopic intrauterine tissue removal device is removed from the operative hysteroscope, and the [unclear] needle is introduced, placed into the myometrium, aspirated, and Vasopressin is injected.
Cardiovascular complications following intramyometrial injection have been reported in isolated cases. To prevent this, low-dose dilute Vasopressin is used, and the surgeon first aspirates to ensure the needle has not inadvertently been placed intravascularly. In this case, the solution is 20 units of Vasopressin diluted in 50ml of normal saline. 4 to 5ml is used. A change in the uterine cavity contour due to the increased myometrial contractility is seen after the injection of the Vasopressin. Almost immediately, hemostasis is achieved.
The uterine cavity is partially de-insufflated to allow further visualization of the base of the fibroid on the anterior wall. This decrease in pressure allows a previously unseen posterior wall fibroid to become visible. It appears to be a submucosal, grade 1. This fibroid is resected with the hysteroscopic tissue removal device. Resection of the base of the anterior wall fibroid is also completed. A normal uterine cavity is restored. The specimen is sent to pathology, and the final report came back as a fibroid with cystic degeneration.
In conclusion, the flow-by technique works well to clear an operative field that has become obstructed with tissue or blood and can help enable complete resection. Direct infiltration of Vasopressin into the base of a myoma during hysteroscopic myomectomy has a rapid onset of action to assist with hemostasis, enabling visualization to perform a complete resection, even when used intraoperatively after bleeding occurs.