Table of Contents
- Procedure Summary
- Authors
- Youtube Video
- What are Surgical Considerations in Parasitic Fibroid Excision?
- What are the Risks of Surgical Considerations in Parasitic Fibroid Excision?
- Video Transcript
Video Description
Key surgical considerations for safely excising parasitic fibroids, with emphasis on identification, vascular control, and minimizing surrounding tissue damage.
Presented By
Affiliations
Sunnybrook Health Sciences Centre, University of Toronto
Watch on YouTube
Click here to watch this video on YouTube.
What are Surgical Considerations in Parasitic Fibroid Excision?
Surgical considerations in parasitic fibroid excision focus on safely identifying and removing fibroids that have detached from the uterus and established an independent blood supply elsewhere in the pelvis or abdomen. These rare FIGO type 8 fibroids can mimic adnexal masses and often arise from pedunculated uterine fibroids that revascularize after detachment or from morcellation fragments after prior surgery.
- Preoperative Imaging: Ultrasound, MRI, or CT helps locate the fibroid, assess its blood supply, and determine proximity to bowel, bladder, and major vessels.
- Anatomic Survey: Careful laparoscopic inspection defines the relationship of the fibroid to pelvic organs and vascular structures before dissection.
- Hemostatic Preparation: Injection of diluted vasopressin into the fibroid capsule reduces intraoperative bleeding and aids dissection.
- Peritoneal Entry and Exposure: The peritoneum overlying the fibroid is incised, and surrounding adhesions are released to expose the stalk or vascular pedicle.
- Layered Dissection: Blunt and sharp dissection is used circumferentially to separate the fibroid while preserving adjacent organs and controlling vessels at the base.
- Stalk Control and Removal: Feeding vessels—often branches of the external iliac or uterine arteries—are coagulated and divided before fibroid removal, followed by meticulous hemostasis and irrigation.
This stepwise approach allows complete removal of parasitic fibroids while minimizing blood loss and protecting nearby organs.
What are the Risks of Surgical Considerations in Parasitic Fibroid Excision?
Excision of parasitic fibroids carries several potential complications that require careful planning and technique.
- Hemorrhage: These fibroids often receive blood supply from pelvic or abdominal vessels, creating a risk of significant bleeding during stalk division.
- Injury to Adjacent Organs: The bowel, bladder, ureters, and pelvic nerves may be damaged during dissection of deeply adherent or vascularized lesions.
- Vascular Injury: Branches of the external iliac or uterine arteries may be encountered at the fibroid base and can cause life-threatening bleeding if not controlled.
- Adhesion Formation: Extensive dissection increases the risk of postoperative pelvic adhesions and chronic pain.
- Infection or Hematoma: The large raw surface created after excision can lead to pelvic abscess or hematoma formation.
- Recurrence or New Lesions: Residual fibroid tissue or morcellation fragments may revascularize and form new parasitic fibroids.
Thorough imaging, strategic port placement, meticulous hemostasis, and careful dissection around critical structures help minimize these risks and ensure a safe, complete excision.
Video Transcript:
Parasitic fibroids, a comprehensive review and surgical considerations for excision. Objectives of this video are to review the types of parasitic fibroids with a focus on pathophysiology and risk factors. We’ll review the literature and present a surgical approach.
Fibroids are typically classified using the FIGO guidelines from a scale of zero to eight. As seen here, the scale is based on the depth of the fibroid within the uterine layers. FIGO type eight includes parasitic fibroids, which will be our focus. The variance of this rare fibroid type include parasitic, IV, disseminated peritoneal, and benign metastasising leiomyomas. These benign tumours look like typical fibroids, both radiologically and histologically, but they tend to grow at unusual locations and can be quite aggressive, causing diagnostic dilemma.
We will then focus on a case of parasitic leiomyoma. First, we’ll discuss parasitic fibroids. They’re either single or multiple pelvic tumours that are separate from the uterus. They exhibit similar clinical behaviour to uterine fibroids in terms of growth and resolution. Their aetiology is not entirely clear, but one theory purports that they originate from pedunculated fibroids which undergo neovascularization from another source, and eventually their original uterine stalk becomes atrophic.
Due to their location in the pelvis, parasitic fibroids can be commonly mistaken for adnexal masses on imaging. Intravenous leiomyomatosis is characterised by the intravascular proliferation of smooth muscle cells, resulting in fibroid-like lesions within venous structures. This condition is associated with an elevated risk for VTE, and can extend to distant vascular territories and sites, including pulmonary vasculature.
Disseminated peritoneal fibroids are characterised by discrete nodules of benign smooth muscles scattered over the peritoneum, which can mimic peritoneal carcinomatosis. If nodules are very small, they may fall below the detection threshold of all radiographic techniques and may only be identified intraoperatively.
Benign metastasising fibroids are characterised by benign-appearing aggregates of smooth muscle cells that can disseminate to distant sites. The lungs are the most commonly-affected location, though lesions have also been reported on the pleura and in the abdominal cavity.
Now, we will discuss pathophysiology of fibroid variants. Firstly, there may be a hormonal predisposition of said peritoneal mesenchymal stem cells to undergo metaplasia under the influence of oestrogen. Genetic mutations on the X chromosome, as well as eight, 12, and 17, have been associated with myoma and disseminated leiomyomatosis.
Anatomic factors contribute, specifically with parasitic fibroids, as they may form from pedunculated fibroids, with neovascularization to external blood supply. Finally, iatrogenic factors most commonly post myomectomy with morcellation as fragments of fibroid can find alternate blood supply and promote growth.
If the patient is asymptomatic, expectant management may be reasonable. If there’s diagnostic uncertainty based on imaging, histological diagnosis should be pursued to rule out malignancy. Medical management can be considered where surgical intervention is less feasible, such as an IV and disseminated peritoneal leiomyomatosis. These tumours are thought to be hormonally responsive like typical fibroids.
Few case reports have described reduction in fibroid size with goserelin injection and ulipristal acetate. Though the number of reported cases is limited, medical management may be a reasonable consideration in appropriately-selected patients. Minimally invasive or open surgical intervention is the most common management described in the literature. Imaging may be useful for surgical planning and assessing proximity and involvement of visceral organs and vascular structures.
We now present our case and outline management. Our 34-year-old nulligravid patient presented with pelvic pain and bulk-related symptoms. Past medical history was significant for a previous hysteroscopic myomectomy and uterine artery embolization. Pelvic ultrasound revealed the findings described here. The largest fibroid measuring 6.1 cm with a pedunculated stalk. As her pain was localised to the area of the fibroid, she opted to have surgical approach.
Step one, identify relevant anatomy and vascular structures that may be involved. Step two, inject vasopressin to the fibroid to reduce surgical blood loss. Step three, open the peritoneum overlying the fibroid to gain access to the myoma itself. Step four, carefully dissect layer by layer until the fibroid can be removed. Step five, haemostasis.
Here is a video of our intraoperative findings. The parasitic fibroid is visualised on the anterior abdominal wall. It was carefully examined for adhesions to surrounding structures and proximity to vascular supply to be avoided, as shown here. After surveying the abdomen and pelvis, consideration is made for the optimal port placement for resection, given the location of our target anatomy.
Next, dilute vasopressin is guided and injected into the myometrium and overlying serosa of the fibroid. Blanching of the superficial and deep vessels can be visualised. When planning the optimal location for creating the peritoneal incisions, factors such as nearby anatomical structures to avoid and blood supply to the fibroid are incorporated. The CO2 laser is used to carefully incise the peritoneum and surrounding adhesions, revealing a fibroid underneath.
Using a combination of blunt dissection and precise incision from the CO2 laser, the peritoneum is grasped and the fibroid is gently separated from surrounding tissue. This is done in a circumferential manner with appropriate use of counter traction. Care is taken to ensure meticulous haemostasis, while striving for complete resection of fibroid tissue without damaging surrounding structures. Once again, blunt dissection technique can be visualised here. The bipolar cautery is used to coagulate superficial vessels on the fibroid.
Nearing the base of the fibroid, a cautious approach is taken as supplying vessels are often found here, including branches from the external iliac artery. The final stalk prior to separation of the fibroid is cauterised well, and then divided using the laser. The round ligament is grasped, and then cauterised ensuring the remaining pedicle is haemostatic. Irrigation is then used to check for haemostasis at the fibroid bed. At the end of the case, you can see the fibroid here, as well as the remaining anterior abdominal wall.
Although fibroid variants are rare, they should be on the differential for patients with a history of fibroids or previous surgery, especially if morcellation was done. They are not always identified on preoperative ultrasound, and thus require a high index of suspicion in patients with risk factors. In patients with pedunculated fibroids, uterine artery embolization is a risk factor for parasitic fibroid and should be avoided.
Resection of parasitic fibroids can be highly morbid, thus adequate preoperative imaging can determine the proximity of critical structures.
Although there remains a paucity of quality evidence, conservative management with GnRH agonists and antagonists can be considered to supress growth. Thank you for watching.
