In nipple ductoscopy, a tiny telescope is placed into a milk duct opening on the surface of the nipple and passed along the ductal tree in a segment of the breast. It is similar to bronchoscopy where a much larger scope in passed from the mouth through the throat and into the air passages in the lungs.
Ductoscopy is extremely useful in patients who have abnormal (pathological) nipple discharge.
Frequently, doctors order a ductogram/galactogram in patients with pathological nipple discharge. However, regardless of whether or not an abnormality is seen on ductogram/galactogram, the duct needs to be surgically excised, so in my opinion this test serves no purpose and I don’t order it.
Except for the ducts directly behind the nipple, milk ducts are usually too small to be seen with the human eye. So, in order to surgically remove a milk duct, many surgeons place a lacrimal probe (this is a relatively large, steel rod with a round tip that was designed to be used in the tear duct of the eye) in the duct where it opens at the nipple, then make an incision and remove the tissue around the probe. This is how I was trained, but I can tell you, it is not very precise. The probe can only be passed a few centimeters, so if the source of discharge is a tumor 5 or 10 cm deep to the nipple, the lacrimal probe technique will miss the abnormality almost every single time. This is scary becauseup to 15% of women will pathological nipple discharge have cancer.
For the past 15 years, I have been using nipple ductoscopy in conjunction with nipple exploration and duct excision in patients with pathological nipple discharge. It is much more precise and the source of the nipple discharge is accurately identified 90% of the time.
The procedure is sterile and it’s done under general anesthetic. The duct producing the discharge is identified and using a series of progressively larger catheters, the ductis dilated to a diameter of 1.1 mm. Then a hollow, 15 cmlong introducing catheter is placed into the duct and the ductoscope is inserted into the introducing catheter. The scope is 0.9 mm wide and has three internal passages or ports: one attached to a light source, one attached to a camera, and one used to continuously push saline (salt water) into the ducts so they stay open, allowing the scope to be advanced safely under direct visualization. The camera magnifies the image 50 to 200 times. Everyone in the operating room can watch as the scope is passed down the duct branches until almost the entire segment is visualizeddirectly. And remember,90% of breast cancers start in the cells that line the milk ducts.
Unfortunately, the scope is too tiny to biopsy through, so once the abnormality is identified, I inject blue dye (I use methylene blue) through the saline port and fill the area with blue dye. The scope is removed, a small incision is made around the areola and the duct containing blue dye is removed and sent to the pathologist for biopsy.
The surgery takes about 90 minutes. Patients go home the same day. Postoperative pain is easily controlled with pain medication for 1 or 2 days.The patient can return to regular activities in 1 to 2 weeks.
The procedure is extremely delicate and it takes a while to perfect it. For instance, it doesn’t take much force to puncture or rupture a milk duct. If this happens, it’s not the end of the world. The duct will heal. But onceruptured, it’s almost impossible to identify the inside (lumen) of the duct again, so the procedure has to be abandoned.
My patients have been happy with this operation because it is both diagnostic and therapeutic: The pathological process causing the fluid production is reliably identified and the patient doesn’t have discharge any more.