LUNA and PSN

What is LUNA?

LUNA stands for Laparoscopic Uterosacral Nerve Ablation. It is a minor addition to laparoscopic surgery for pelvic pain. It refers to methods of interfering with the function of the nerves that supply the posterior uterus at the level of the upper cervix and the lower uterine segment.

The actual technique involves treating a 1-2 cm segment of the uterosacral ligament that carries the nerve. A little beyond the point of insertion into the posterior uterus this ligament is treated by transection, ablation, or cauterization resulting in an interruption in the pathway carrying sensory signals back to the brain.

Does It Hurt Anything?

The human body does not seem to notice the transection of this nerve. I have never had a patient have any loss of desirable sensation. Patients generally experience no identifying symptoms from this procedure.

The uterosacral ligament is a soft, loose structure in most women. It does not perform any structural function which is interfered with by the LUNA. After the LUNA is performed, the ligament returns to a surprisingly normal appearance.

Can There Be Complications?

Ureteral injury could occur if the ureter happens to run within the ligament (which is very rare) or posterior to it. The ureter should always be identified first so that it can be protected during the procedure. There is also a small blood vessel running in the ligament which frequently requires cauterization or coagulation. Generally, LUNA is a very straightforward procedure.

Does It Help Pelvic Pain?

Many surgeons have been observed improvement in pelvic pain and backache after this procedure is performed. In my experience, I have noted mixed results: sometimes pain is lessened, sometimes it is not. Once in a great while I have a patient with a negative laparoscopy. In these women I have noted improvement in some of their symptoms after LUNA.

When Do I Do It?

I believe that endometriosis must be totally excised in order to be effectively treated. Because the uterosacral ligaments are one of the most common locations for endometriosis to be found, I routinely excise endo from them. This effectively results in LUNA. I rarely choose to perform LUNA on a totally normal uterosacral ligament if other obvious causes for pelvic pain are found. I would be inclined to perform LUNA if no other cause for pain is found.

Is Presacral Neurectomy the Same as LUNA?

Absolutely not!

Presacral neurectomy (PSN) is similar only in that it, like LUNA, is a technique for destroying the ability of certain nerves to function normally. PSN carries with it a bit more risk than LUNA. It involves transecting the multiple cobweb-like presacral nerves after they cross the pelvic brim just below the bifurcation of the large blood vessels (vena cava) and medial to the ureter.

When Is PSN Recommended?

Some gynecologists use this procedure to try to relieve central pelvic pain when they feel they must do something more than conventional surgery. This operation is not usually suggested except when pain is primarily central (as opposed to lateral such as ovarian pain).

Do You Perform PSN?

I have not had good success with PSN. I do have several physician friends who are much more convinced of its advantages than I am. I am of the opinion that we should always keep looking for causes for pain rather than just trying to mask the results of it.[../../_private/news_footer.htm]