An HSG can elucidate the contour of the endometrial cavity and any communications including tubal patency. HSG is not universally considered a reliable diagnostic strategy, however, as the serosal surface of the uterus is not examined.
Images courtesy Dr. Megan Daw
Hysteroscopic view of a completed transection of uterine septum. There is a uniform appearance of the uterine fundus and the transecting incisions have been made equidistant between the anterior and posterior walls.
By contrast, as Dr. Fedele has demonstrated, sensitivity and specificity may be up to 100% with the use of 3D sonography. Ultrasound also can provide an assessment of other pelvic structures, such as ovaries and kidneys, that may contribute to a patient’s symptoms or be associated with Müllerian anomalies.
MRI is another noninvasive diagnostic strategy for characterizing Müllerian anomalies. It is both sensitive and specific, and is considered a valuable strategy as it allows for thorough evaluation of both the internal and external contour of the uterus.
Although advancements in MRI and ultrasound have improved diagnostic accuracy, concurrent laparoscopy at the time of hysteroscopic treatment remains the standard in confirming the diagnostic impressions formed by initial imaging. At our institution, we employ a combination of in-office 2D and 3D ultrasound, as well as saline infusion sonohysterography, and then confirm our findings laparoscopically at the time of surgery.
Treatment, Complication Risk
Uterine septa classically were treated with abdominal surgery, but advances in operative hysteroscopy have led to equally efficacious treatment with the advantage of decreased morbidity.
Potential intraoperative complications of hysteroscopic transection of uterine septa include bleeding, distention media overload, and perforation, with an associated risk of damage to nearby structures. Generally, septa are avascular, making the risk of both hemorrhage and distention media overload quite minimal. These complications are on the order of less than 1%, and typically the procedure is performed without incident on an outpatient basis.
Delayed complications of hysteroscopic septoplasty include the formation of intrauterine adhesions and the risk of uterine rupture with subsequent pregnancies. Although case reports of uterine rupture after hysteroscopic septoplasty exist, rupture is a very rare event because the integrity of the myometrium is generally preserved.
Adhesion formation, however, has been reported in up to approximately 7% of cases following hysteroscopic transection of uterine septum, according to a review published last year (Semin. Reprod. Med. 2011;29:83-94). Adhesion formation can further compromise the gestational performance of these patients.
Operative Technique
In preparation for operative hysteroscopy, many surgeons recommend priming the endometrial lining to provide optimal visualization. Progestins, oral contraceptive pills (OCs), or a GnRH analog can be used for this purpose. Alternatively, the procedure may be coordinated or timed with the patient’s early proliferative phase.
Hysteroscopic treatment involves incising the uterine septum and allowing the fibromuscular tissue to retract to the level of the surrounding endometrium. Surgeons have used microscissors, electrosurgery, or even fiberoptic laser energy, although this latter technique is currently less common given its expense, manipulation difficulties, and requirement for specialized training.
Although energy-based techniques provide hemostasis and may offer greater ease to a procedure involving a thick septum, use of these techniques increases the risk of postoperative intrauterine adhesion formation from endometrial and myometrial thermal damage. The use of microscissors, an energy-free technique, avoids thermal damage to the surrounding tissue and the subsequent increased risk of intrauterine adhesive disease.
Images courtesy Dr. Megan Daw
5-french semi-rigid scissors are used for hysteroscopic transection of uterine septum. Note how the fibromuscular tissue of the septum retracts to the level of the surrounding endometrium.
A 12- or 25-degree lens provides accurate and continuous orientation of the ostia and instruments. A 5-7 Fr semi-rigid scissors offer sturdiness and maneuverability.
The surgical technique involves the incision of the septum equidistant between the anterior and posterior walls and traveling toward the fundus without inciting trauma to the myometrium of the fundus. Specifically, the septum is incised with both ostia in the visual field and midway between the anterior and posterior wall of the uterus. The incision is extended cephalad to the level of the uterine fundus.
If a broad septum limits visualization of both ostia, sequential thinning incisions are made along each side of the septum from the apex to the fundus. These incisions create a wedge that can ultimately be transected. The end point may be subtle, but continuous movement from one ostium to the other with the hysteroscope, and a uniform appearance of the uterine fundus, should be achieved. Bleeding may be an additional indication that the septum has been completely transected as this indicates myometrial disruption.