The Predictive Value of the Sliding Sign in the Evaluation of Deep Infiltrating Endometriosis

Objective: To evaluate preoperative real-time dynamic transvaginal sonography (TVS) in the 
prediction of pouch of Douglas (POD) obliteration in women undergoing laparoscopy for suspected 
endometriosis. Methods: This prospective controlled study was conducted in the department of 
Obstetrics and Gynecology, Faculty of Medicine, Minia University. All women with symptoms 
suggestive of endometriosis who were scheduled for laparoscopy underwent detailed preoperative 
TVS, in particular to ascertain whether the POD was obliterated. POD obliteration was assessed using 
a real-time TVS technique called the ‘sliding sign’. Preoperative TVS sliding sign findings were then 
compared to gold standard laparoscopic POD findings. Results: Initially, fifty-eight (58) patients in 
their reproductive age were enrolled into this study, but eight patients (8) were excluded as some of 
them refuse to do laparoscopy and some get pregnant . Thus, This study included fifty (50) patients 
aged between 18-40 years (29.2+6.7). The frequency of relevant symptoms include dysmenorrhea 
(66%), It iliac fossa pain (17%), rt iliac fossa pain (16%), dyschezia (22%), diarrhea (14%), 
constipation (8%), rectal bleeding (5%), and dyspareunia (28%). The results of TVS include positive 
sliding sign which means POD is patent in 39 patients (78%), negative sliding sign which means 
POD is obliterated in 11 patients (22%), endometrioma was present in 9 patients (18%), bowel DIE 
was present in 3 cases (6%) and adenomyosis was present in 6 patients (12%). The laparoscopic 
results include patent POD in 35 patients (70%), obliterated POD in 15 patients (30%), endometrioma 
was present in 9 patients (18%), bowel DIE was present in 5 cases (10%) and adenomyosis was 
present in 8 cases (16%). The sensitivity, spechficity, PPV and NPV for the use of the sliding sign to 
predict POD obliteration were 73.3% , 100%, 100% and 89.7%. Conclusions: Preoperative real-time 
dynamic TVS evaluation using the sliding sign seems to establish with a high degree of certainty 
whether the POD is obliterated. Given the increased risk of deep infiltrating endometriosis in women 
with POD obliteration, the TVS sliding sign technique may also be useful in the identification of 
women who may be at a higher risk for bowel endometriosis.