Deep infiltrating endometriosis

There was an interesting study from a French group in the on-line version of Fertility and Sterility this week.  The researchers compared the clinical records of 229 women with endometriosis; 98/229 had severe or "deep infiltrating endometriosis", 131/229 had more superficial patterns.  They found <!--more---> that patients with DIE had: a positive family history of endometriosis (odds ratio [OR] = 3.2); more absenteeism from school during menstruation (OR = 1.7; 95% CI: 1–3), OCP treatment for dysmenorrhea (OR = 4.5).  Dr Chapron, the senior author, doubted whether diagnosing endometriosis earlier will eventually lead to fewer cases of DIE and less need for surgery.

We do not have the full paper as yet.  It will be interesting to see - if the information is available - (1) how many girls had severe and constant pain from the age of onset of their menstrual periods (menarche). In the denervation-reinnervation view, that implies any injury to pelvic nerves takes place before the age of 12. Pain is severe at menarche because that is when oestrogen-dependent changes in pelvic blood flow, take place.  (2) What proportion of these young girls had sustained bowel problems, either in infancy associated with bottle-feeding or toilet training, or, in subsequent years ? If bowel habits do not change then the disease will simply "progress". Finally, (3) are there any other potential sources of injury to pelvic nerves in these patients ?

Stages of endometriosis (revised AFS stages I-IV)

Revised American Fertility Society scores (0-5 = stage 1, 6-16 = stage 2, 16-40 = stage 4, >40 = stage 4) suggest a progression of "endometriosis" that coincides with symptoms and laparoscopic scores.  Neither is true.  In fact there looks like three forms of chronic pelvic pain - (1) CPP with no endometriosis (2) CPP with minor endometriosis (<15) (3) CPP with major endometriosis (>15) ......  and these are <!--more---> separate entities rather than a progression of the condition.

What is absolutely clear is that symptoms such as chronic pelvic pain, bear no relationship to the extent of the endometriosis found at laparoscopy.  For the most part this is predictable from a consideration of the aetiology.  Advanced nulliparous endometriosis associated with persistent physical straining during defaecation results from recurrent events and score heavily (particularly since fusion of the rectum to the vagina scores 20 points, stges 3/4).  Whereas significant injuries in childbirth are one-off injuries and the presence or absence of endometriosis may depend on choice of feeding; breastfeeding results in no endometriosis (yet plenty of pain, stage 0) though bottlefeeding results in early menstruation before the intrapartum injuries heal up (also plenty of pain, stage 1/2). 

Net result is that scores bear no relationship to symptoms, and, stages of endometriosis do not change significantly throughout the course of the condition. Surgical removal of endometriosis without dealing with underlying abnormal nerves, may not be entirely helpful.

NGF in endometriosis

A paper from Berlin in Fertility and Sterility (November 2010) "Overexpression of nerve growth factor (NGF) in peritoneal fluid from women with endometriosis promotes neurite outgrowth in endometriotic lesions" by Dr de Arellano and colleagues, finds exactly what the title says. New, abnormal nerves occur in peritoneal lesions in assoication with increased concentrations of nerve growth factor (NGF). This group have been doing a series of careful studies focussed on the neurological content of peritoneal lesions over the past few years - Sydney, Hangzhou, Leuven, Berlin, etc.

Various interpretations may be given to these observations but they add to the growing weight of evidence that injuries to pelvic nerves are the source of most clinical symptoms in clinical endometriosis.

Chronic pelvic pain in China

More uterosacral injuries at laparoscopy.  On this occasion a Chinese patient, delivered in Hangzhou - which is interesting because the CS rate is 60-70% and there are correspondlingly few vaginal deliveries. On this occasion there is absent of the left uterosacral ligament that is plastered against the left pelvic side wall.  The right uterosacral ligament is almost intact.  In this patient the features are clearly defined because of the prior procedure to remove the left ovarian endometrioma - by a second year resident.  Peritoneal lavage with normal saline outlines the key anatomical features.

Levator injuries in chronic pelvic pain - BJOG, November 2010

“Intrapartum risk factors for levator trauma” is the title of an Australian paper in BJOG this month (November, 2010) where the authors did MR scans four months after the first labours of 367 women. 32/367 women suffered irreversible injury to their pelvic floor muscles (levator ani). The important risk factors were forceps delivery (OR 3.83) and prolonged second stage (OR 1.01) <!--more--->.

The important features of this study are that it looks at a large number of women with an expensive instrument – and finds a high rate of injury to the levator muscles. From the standpoint of women with chronic pelvic pain it is important because if you have injured the muscles of the pelvic floor it is likely that you have injured the large nerve bundles that lie closer to the baby than the muscle. There are no symptoms of pelvic pain at four months after delivery but that may well be different at five years.

Chronic Pelvic Pain and the BMJ

The BMJ carried a review of chronic pelvic pain today (8th October 2010 BMJ 2010; 341:772-5) by Dr Jane Daniels and Professor Khalid Khan. It was a review of the known facts. The highlight was some research funding to study the .....

Endometriosis explained - a new website

In view of the level of interest in the denervation-reinnervation view of endometriosis, a new website - www.endometriosisexplained.com - has been published.