**7. Prediction of postoperative pain**

There has been a great deal of interest in the prediction of postoperative pain, but most of the studies have not included laparoscopic pelvic surgery. The situation is very complex with a wide number of variables having a role such as preoperative pain, depression, previous surgery, gender, and opiate use and abuse. A study of the assessment of predicting postoperative pain considered these elements but also included testing for the presence of allodynia and hyperalgesia before and after 6 months following laparoscopic surgery for non-acute pain. Hyperalgesia was identified with the use of a Somedic Algometer (Somedic SenseLab AB, Norra Mellby 1129 SE-280 10 Sösdala, Sweden). In women who underwent tubal ligation, pain levels were low before and after the procedure. In 61 women who underwent surgery for non-acute pain, pain levels at 6 months and all psychologic test scores were reduced significantly compared with baseline (P < .001 and P = .001, respectively). Among those women with positive results on the quantitative pain tests of sensitization at baseline, average postoperative pain was also significantly reduced (P < .001). Univariate analysis demonstrated only tests of sensitization were correlated with the reduction in average pain level (P = .01). Regression analysis suggested that baseline pain, catastrophizing, and the presence of cutaneous allodynia significantly predicted pain levels after 6 months. We had anticipated sensitization would have predicted more pain, but we have interpreted the results to indicate the reduction in pain may be due to the successful removal of a nociceptive source in the pelvis. At present, pain testing does not indicate whether surgery should or should not be done; that remains a clinical decision.

#### **8. Detection of sensitization in relation to psychological status**

Also, a secondary analysis reviewed the changes in pain and psychological measures of stress (Pain Disability Index, Pain Catastrophizing Scale, CES-D (Center

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*Pain Testing in Endometriosis for the Clinician DOI: http://dx.doi.org/10.5772/intechopen.92756*

measures of psychological distress [16].

dynia on the perineum was validated as noted above [13].

for repetitive laparoscopic surgery of limited, if any, benefit.

**10. Possible future benefits of pain testing**

of cohorts of subjects in clinical trials.

pain testing for sensitization.

**9. Relationship to pelvic floor**

for Epidemiologic Studies Depression Scale)), depression scale, and the McGill Pain Scale (short form) as the presence of pain sensitization. Preoperatively, the psychological test scores correlated significantly with the pain scores. Post-laparoscopic surgery pain and psychosocial test scores were reduced and remained significantly correlated. The presence of preoperative pain sensitization was associated with trends to greater baseline and 6-month postoperative changes in average pain and

In a study of 112 women with chronic pelvic pain assessed for pain in the abdominal wall, perineum, levator ani, and obturator internus, the number of myofascial trigger points was predicted by the number of previous laparoscopies adjusted for age. Both the presence of visceral disease and endometriosis were significantly associated with higher numbers of myofascial dysfunction than the absence of these conditions [17]. These findings suggested that prior surgery may aggravate pain sensitization. The available studies using pain testing do not indicate they can discriminate endometriosis from other visceral diseases [3, 13, 18]. It should also be noted here the test for allo-

It has long been known that the extent of disease does not have a correlation with the severity of pain. Many women with minimal disease are severely incapacitated with their pain. Alternatively, but less common, are women with severe stage 4 disease without pelvic pain. Many gynecologists have seen women who have had repeated procedures for minimal disease despite having no change in their pain [18]. The techniques of pain testing can provide an assessment indicating peripheral and central sensitization have altered pain physiology and possibly eliminate the need

There have been several blinded controlled trials of the excision versus sham excision of endometriosis for the management of pain [19–22]. The results have differed; in several, there was a reduction in pain; in another that was extended out 14 years post-randomization, there was no difference between the sham excision and excision. Perhaps it may not be the surgeons' expertise, the degree of disease, or prior pelvic surgery, but the differences may possibly be explained by the womens' pain sensitization. Pain testing might have a unifying feature to allow comparisons

Many surgeons have had the unsettling experience of having one of their women undergo what is considered a straightforward operation of hysterectomy, tubal ligation, or laparoscopic excision of endometriosis in which the woman returns with severe incapacitating pelvic pain. The reason is not in the operative procedure that was uncomplicated, but it is difficult at times to persuade that to the woman involved. Possibly, there was a preexisting state that made this possible. In reviewing women presenting with postoperative onset of chronic pelvic pain, there is commonly a history of pain preceding the operation. This can take the form of severe dysmenorrhea, repetitive bouts of cystitis, or prior kidney stones. Pain causes chronic pain and while it is possible to generate chronic pelvic pain from an isolated procedure, it is much more common to see there was a previous pattern of repetitive pain. The shift to a chronic pain state might be identified as a risk with

*Pain Testing in Endometriosis for the Clinician DOI: http://dx.doi.org/10.5772/intechopen.92756*

*Endometriosis*

laparoscopy.

**6. The negative laparoscopy**

**7. Prediction of postoperative pain**

should not be done; that remains a clinical decision.

**8. Detection of sensitization in relation to psychological status**

Also, a secondary analysis reviewed the changes in pain and psychological measures of stress (Pain Disability Index, Pain Catastrophizing Scale, CES-D (Center

groups. The cotton-tipped applicator test showed 73% sensitivity and 100% specificity for differentiating patients with chronic pelvic pain from pain-free patients [14]. At present, there do not appear to be pain-testing techniques that specifically identify endometriosis independent from other visceral diseases. It is arguable, however, that the experience of pain may have greater relevance depending on the clinical situation as described in relation to the negative

A comparison of the results of pain testing was done in women investigated for pelvic pain between 69 with confirmed endometriosis compared to 35 who had a negative laparoscopy [15]. When women with a negative laparoscopy were compared to those with confirmed endometriosis, there were no differences in age, gravidity, parity, menarche, and frequency of dyspareunia or duration of severe dysmenorrhea. There were no differences in the frequency of abdominal wall allodynia or of pressure pain thresholds. These tests give validation to the women who otherwise have no explanation and it also raises the possibility that dysmenorrhea may be the source of the pelvic pain. These results are consistent with testing

of women with persistent pelvic pain with and without endometriosis [3].

There has been a great deal of interest in the prediction of postoperative pain, but most of the studies have not included laparoscopic pelvic surgery. The situation is very complex with a wide number of variables having a role such as preoperative pain, depression, previous surgery, gender, and opiate use and abuse. A study of the assessment of predicting postoperative pain considered these elements but also included testing for the presence of allodynia and hyperalgesia before and after 6 months following laparoscopic surgery for non-acute pain. Hyperalgesia was identified with the use of a Somedic Algometer (Somedic SenseLab AB, Norra Mellby 1129 SE-280 10 Sösdala, Sweden). In women who underwent tubal ligation, pain levels were low before and after the procedure. In 61 women who underwent surgery for non-acute pain, pain levels at 6 months and all psychologic test scores were reduced significantly compared with baseline (P < .001 and P = .001, respectively). Among those women with positive results on the quantitative pain tests of sensitization at baseline, average postoperative pain was also significantly reduced (P < .001). Univariate analysis demonstrated only tests of sensitization were correlated with the reduction in average pain level (P = .01). Regression analysis suggested that baseline pain, catastrophizing, and the presence of cutaneous allodynia significantly predicted pain levels after 6 months. We had anticipated sensitization would have predicted more pain, but we have interpreted the results to indicate the reduction in pain may be due to the successful removal of a nociceptive source in the pelvis. At present, pain testing does not indicate whether surgery should or

**66**

for Epidemiologic Studies Depression Scale)), depression scale, and the McGill Pain Scale (short form) as the presence of pain sensitization. Preoperatively, the psychological test scores correlated significantly with the pain scores. Post-laparoscopic surgery pain and psychosocial test scores were reduced and remained significantly correlated. The presence of preoperative pain sensitization was associated with trends to greater baseline and 6-month postoperative changes in average pain and measures of psychological distress [16].
