Table of Contents
- Procedure Summary
- Authors
- Youtube Video
- What is Hysteroscopic Management of Interstitial Ectopic Pregnancy?
- What are the Risks of Hysteroscopic Management of Interstitial Ectopic Pregnancy?
- Video Transcript
Video Description
A minimally invasive hysteroscopic approach to managing interstitial ectopic pregnancy, emphasizing technique, safety, and uterine preservation outcomes.
Presented By
Affiliations
Trillium Health Partners, Mount Sinai & Women’s College Hospital, University of Toronto
Watch on YouTube
Click here to watch this video on YouTube.
What is Hysteroscopic Management of Interstitial Ectopic Pregnancy?
Hysteroscopic management of interstitial ectopic pregnancy is a minimally invasive approach to treat pregnancies implanted in the interstitial (intramural) segment of the fallopian tube while preserving the uterus. Here’s what it involves:
- Diagnosis and Localization: Accurate imaging with ultrasound and hysterosonography identifies a gestational sac within the interstitial portion of the tube, typically with a thin surrounding myometrial layer and the characteristic interstitial line sign.
- Preoperative Planning: Laparoscopic guidance is used to confirm the diagnosis, assess myometrial thickness, and differentiate interstitial from intrauterine or cornual pregnancies.
- Vasopressin Injection: Dilute vasopressin is injected into the cervix or myometrium to minimize bleeding during resection.
- Hysteroscopic Resection: Using a hysteroscope with mechanical tissue removal or resection loops, the products of conception are carefully excised under direct visualization, with simultaneous laparoscopic transillumination to monitor uterine wall thickness and prevent perforation.
- Final Inspection: The cavity is inspected to ensure complete removal, and a tubal dye test may be performed to confirm tubal patency and integrity of the myometrium.
This approach allows targeted removal of the ectopic pregnancy while avoiding more invasive procedures such as cornuectomy or salpingectomy.
What are the Risks of Hysteroscopic Management of Interstitial Ectopic Pregnancy?
Although less invasive than traditional surgery, this technique carries specific risks that require careful intraoperative monitoring.
- Severe Hemorrhage: The interstitial region is highly vascular, and incomplete vasopressin effect or deep resection can result in significant bleeding.
- Uterine Perforation: Thin residual myometrium increases the risk of uterine rupture during resection or in future pregnancies.
- Incomplete Removal: Retained products can lead to persistent bleeding, infection, or the need for repeat surgery.
- Infection: Endometritis or pelvic infection may occur despite sterile technique.
- Future Pregnancy Complications: Myometrial thinning at the resection site can increase the risk of uterine rupture or abnormal placentation in subsequent pregnancies.
- Anesthetic and Fluid Overload Risks: Hysteroscopic procedures carry the potential for fluid absorption, electrolyte imbalance, or anesthesia-related complications.
Careful preoperative imaging, combined hysteroscopic and laparoscopic guidance, and meticulous control of bleeding help minimize these risks while preserving fertility.
Video Transcript:
This video demonstrates the hysteroscopic management of an interstitial ectopic pregnancy. The objectives are to help identify a proximal interstitial ectopic pregnancy on ultrasound and at laparoscopy, and to demonstrate a hysteroscopic surgical approach.
Our patient was a healthy 38-years-old G3P0 with a recent miscarriage managed by D&C. Postprocedural ultrasound showed retained products of conception. An attempted misoprostol was unsuccessful, requiring a second D&C. At the time of referral two months later, she had ongoing spotting and a beta-hCG of 37.
The ultrasound revealed a normal size anteverted uterus and a thin endometrial lining. Avascular area [?] measuring 2 cm was identified in the left fundal area. It appeared to be bulging from the interstitial portion of the fallopian tube, with only minimal residual myometrial thickness. With sonohysterogram, the location was confirmed to be in the left interstitial. It, however, seemed to be communicating with the uterine cavity, indicating more of a proximal implantation.
An interstitial ectopic pregnancy is a rare form of ectopic pregnancy, when the embryo implants in the most proximal segment of the fallopian tubes that is embodied in the myometrium. It’s associated with a mortality rate of 2.5%, which is seven times higher than all types of ectopic pregnancy combined. That’s why early and accurate ultrasound diagnosis is important.
Ultrasound criteria were proposed to help in the diagnosis of interstitial EP. The criteria include an empty uterine cavity, gestational sac at least 1 cm separated from lateral edge of the uterine cavity, and thin myometrial layer of 5 mm or less surrounding the gestational sac. Using these criteria, it showed a specificity of 90% to identify an interstitial EP. The most specific ultrasound criteria remains the interstitial line, which represents an echogenic line seen medial to the gestational sac and connecting to the endometrial cavity.
A more precise classification of the interstitial EP has been suggested based on its location along the 1 to 2 cm length of the interstitial portion of the fallopian tube, allowing for targeted surgical management. Based on the precise site of implantation, the least invasive surgical approach is suggested.
When the implantation occurs in the distal portion of the interstitial tube, it tends to expand laterally into the isthmic portion of the fallopian tube and dilating it as such. A retrograde milking technique and salpingectomy can be attempted. When it implants in the central portion, the classic surgical management would include cornuectomy or cornuostomy, but a combination of technique to minimise blood loss. When a pregnancy implants proximally, hysteroscopic resection with laparoscopic guidance is being proposed.
Based on the hysterosonogram, a proximal implantation was suspected in our patient. We will demonstrate a stepwise approach to an hysteroscopic resection of a proximal interstitial EP. Step one, confirm the location. At laparoscopy, it’s important to distinguish a proximal interstitial EP from an intrauterine pregnancy at the uterotubal junction, as the latter would represent a viable pregnancy. An expectant management could be offered.
When examining at laparoscopy, an interstitial pregnancy usually shows lateral distension of the uterus and displacement of the round ligament upward and medially, whereas in intrauterine pregnancy at the cornua would induce a lateral enlargement of the uterine cornua, displacing the round ligament upward and outward.
The location of the pregnancy can also be confirmed by hysteroscopy. Initial evaluation of the cavity revealed an empty uterine cavity with bilateral ostium in view. Upon further evaluation of the cavity, we could visualise calcified products of conception that were implanted in the proximal aspect of the left interstitial tube, confirming our diagnosis.
Step two, injection of vasopressin. To reduce blood loss, consider injection of vasopressin in the cervix or directly into the myometrium. Step three, hysteroscopic resection under laparoscopic guidance. Hysteroscopy was performed using a 6 mm hysteroscope. Using a mechanical hysteroscopic tissue removal system, products of conceptions were carefully resected. Transillumination with the laparoscope was used throughout the procedure to enhance visualisation.
A laparoscopic light source was directed into the uterine wall, allowing real-time assessment of residual myometrial thickness. This technique was repeated at various point to ensure adequate myometrial layer. Additionally, transillumination helped highlight any remaining areas of products of conception appearing as irregular or hypervascular tissue, adding further targeted removal. The anatomy can easily become distorted with hydrodissection.
To assist in identifying key anatomical landmarks, the laparoscopic assistant gently probe the fallopian tube at various levels, using atraumatic graspers. This allows for clear delineation of the uterine cavity, isthmic portion and interstitial segment of the fallopian tube.
By correlating laparoscopic and hysteroscopic views, we were able to accurately determine which portion of the fallopian tubes was being visualised during hysteroscopy. Final inspection of the uterine cavity showed an empty left cornua with no residual products of conception.
Step four, tubal dye test. Tubal patency was confirmed by visualisation of bilateral spillage. Following tubal dye test, a portion of the resection area allowed for delineation of the prior implantation site. It confirmed our suspicion of proximal interstitial EP, and illustrates well the upward and medial displacement of the round ligament.
At eight weeks post-op, our patient had resolution of menses and negative beta-hCG. The hysterosonogram showed a normal uterus with thin endometrium. Good myometrium thickness was visualised throughout, without any evidence of [unclear] bulging at the left uterine cornua.
In conclusion, accurate and precise diagnosis of proximal interstitial pregnancy is essential. And once confirmed, it can be treated with hysteroscopy, avoiding a more invasive surgical approach.
