LUNAPSN

Understanding LUNA & PSN

It's no secret that pelvic pain is one of the leading symptoms of Endometriosis. Ranging from cyclical, "crampy aching" to debilitating, chronic pain, specific medications may provide temporary relief. However, such measures rarely solve the problem on a long-term basis. Can surgery help?

Studies have shown that thorough excision of Endometriosis implants offers patients the best outcome. Even in absence of excision surgery, however, two procedures may offer a woman relief from dysmenorrhea and pelvic pain.

LUNA & PSN

Laparoscopic Uterosacral Nerve Ablation and Pre-Sacral Neurectomy involve the laparoscopic transection, ablation or cauterization of the pathways carrying pain signals back to the brain. By interrupting these nerves, many women experience a relief in the pelvic and back pain associated with Endometriosis [and with other non Endometriosis-related causes of pain].

In LUNA, a small [1-3 cm] nerve near the back of the uterus is transected through the methods outlined above. This is the more commonly performed of the two procedures, but indicated by specialists to be the least effective. The risks associated with this procedure are also less than that of the PSN; but of course, it should still be performed only by an Endometriosis specialist. Ureteral injury could occur in rare instances; however, it is very straightforward procedure.⁽¹⁾

The PSN is slightly more complicated to perform, but some surgeons feel that the PSN offers more effective relief than the LUNA. With PSN, the weblike pre-sacral nerves [also in the back of the uterus, but higher up] are transected. Because these nerves are just below the Vena Cava [a major blood vessel] and closer to the ureter, significant risks are involved.⁽¹⁾ In rare instances, the PSN can be too effective: some women who had previously undergone the procedure did not realize they were in labor.

You can see a picture of a PSN procedure performed by the Collaborative Healthcare Group here.

Similar in concept, yet glaringly different in application, the LUNA and PSN have long been the subject of debate by surgeons in the gynecology community. In one study⁽²⁾ comparing LUNA and PSN, researchers concluded that the efficacy of both methods was nearly equal [87.9% versus 82.9%] at the 3-month postop visit, but the efficacy of PSN was significantly better than that of LUNA [81.8% vs 51.4%] at the 12-month
visit.

A similar study supported these findings,⁽³⁾ concluding that PSN was shown to be significantly more effective in the long term. This study also found that adverse events were significantly more common in PSN patients.

Still another study⁽⁴⁾ found that LUNA was no more effective than simple excision of endometriotic lesions for pain relief. In a 12-month follow-up, recurrence of moderate to severe dysmenorrhea was 33.7% in the LUNA group and 27.5% in the excision surgery group. 68% of patients in the LUNA group were "very satisfied" or "satisfied" with their treatment, as opposed to 73% in the excision group. The study concluded that "adding LUNA to surgery for Endometriosis does not enhance pain relief."

Other physicians interviewed on the study results said they would "continue to perform LUNA" on specific patients, such as those women with crampy, lower pelvic pain that starts before the menstrual period.

Both techniques have the potential to relieve lower back, ovarian and central pelvic pain; however, as with all aspects of this disease, there is no guarantee that an individual will reap the same benefits as another, nor will their experience with either procedure likely be the same. Each woman will need to carefully evaluate her situation with her Endometriosis specialist to determine if indeed a LUNA or PSN is a viable option for her.

You can speak with others who have undergone these procedures by joining a local support group, whether online or in your community. Contact the Endometriosis Research Center for a group near you, or join the ERC Listserv online by visiting http://groups.yahoo.com/group/erc.

References:
(1) Robert B. Albee, MD, Director, Center for Endometriosis Care.
(2) "Comparison of Laparoscopic Presacral Neurectomy and Laparoscopic Uterine Nerve Ablation for
Primary Dysmenorrhea;" by Fang-Ping Chen, M.D., Shuenn-Dyh Chang, M.D., Kiu-Kwong Chu, M.D. & Yung-Kuei Soong, M.D.; J Reprod Med 1996;41:463# 466.
(3) "Surgical Interruption of Pelvic Nerve Pathways for Primary and Secondary Dysmenorrhea;" by Wilson ML, Farquhar CM, Sinclair OJ, Johnson NP. Cochrane Review # ab001896-20004.
(4) "LUNA Does Not Ease Dysmenorrhea with Endometriosis;" Medical Tribune - Internist & Cardiologist Edition 38(20): 1997.

HOME