To the Editor:I read with great interest the excellent paper by Dr C. Paul Perry, (Current concepts of pelvic congestion and chronic pelvic pain. JSLS. 2001;5:105–110). It is true that association between pelvic congestion (pelvic varicosities) and chronic pelvic pain is more of a diagnosis of exclusion (absence of other findings) rather than the primary finding we are looking for. The data on the incidence of pelvic varicosities in patients with chronic pelvic pain is scarce and often contradicts our assumption of such an association. Kresch et al found during laparoscopy that out of 100 women suffering from chronic pelvic pain 3% had large pelvic veins, but among 50 asymptomatic women undergoing tubal ligation large pelvic veins were found in 15%.[1] The valvular insufficiency theory cannot be supported by the fact that pain due to pelvic varicosities disappears after menopause. If valvular incompetence is a primary reason, one would expect pain to increase with age. On the other hand, we all have been in the position of, during laparoscopic examination of patient with chronic pelvic pain, not finding endometriosis, occult or overt hernias, or adhesions, yet looking at the pelvis we were convinced that this patient had pelvic pain because the pelvis was congested. The congestion did not have to take the form of pelvic varicosities. It could appear as hundreds of dilatated small arteries and venules visible through the peritoneum.Pelvic congestion is not a cause of pain, but rather the symptom of the condition maintaining the pain. I would like to offer a different explanation for the mechanism of chronic pelvic pain in some women, especially these with diffuse pelvic congestion.Some women with chronic pelvic pain suffer from a form of reflex sympathetic dystrophy (RSD) and sympathetically maintained pain (SMP) involving the pelvis. For them, minimal endometriosis, occult hernias, and pelvic adhesions are the triggers rather than the cause of pain. Chronic pain is a complex system of maladjustments within the body and the nervous system and in particular the autonomic nervous system. The autonomic nervous system is the operating system of our body; it runs programs (routines) to maintain homeostasis within our body despite changing external and internal environments.[2] It is an interface between higher neurologic functions (thought, conscious and unconscious emotions) and effectors on the periphery (mechanical, immune system, hormonal system, circulation, etc.) In chronic pain, malfunction occurs within the autonomic nervous system, and new faulty routines are developed which instead of mitigating the pain, maintain it.[3] Because of the unique position of the autonomic nervous system as an interface, occurrence and management of pain can be affected by emotional status, psychotherapy, psychopharmacology, surgical intervention, nerve ablations, acupuncture, physical therapy, and many other treatment methods. The format of this letter prevents me from fully describing this concept, but it certainly is worth looking into in the future.Sincerely,