S. Winder

Sonovaginography: redefining the concept of a “normal pelvis” on transvaginal ultrasound pre‐laparoscopic intervention for suspected endometriosis

Office sonovaginography (SVG) challenges the concept of the “normal” pelvic ultrasound in women with chronic pelvic pain and suspected endometriosis. When positive for posterior compartment deep infiltrating endometriosis, with or without Pouch of Douglas obliteration, office SVG allows for triaging of women to the appropriately trained advanced laparoscopic gynaecological and colorectal surgical team. We advocate that all women with suspected endometriosis undergo office SVG prior to laparoscopy to ensure an accurate pre‐operative mapping of endometriosis disease location and extension.

Ultrasound diagnosis of ectopic pregnancy

Ectopic pregnancy (EP) remains the number one cause of first trimester maternal death. Traditionally, laparoscopy has been the gold standard for diagnosis of EP. The advent of high‐resolution transvaginal scan (TVS) means more clinically stable women with EPs are diagnosed earlier, well before surgery becomes necessary in many cases. Early diagnosis by TVS is therefore potentially life saving and can reduce surgical morbidity by allowing elective surgery or even non‐surgical conservative treatment options. Combining transabdominal and transvaginal scanning confers no benefit over transvaginal scanning alone. Reports that reads “…empty uterus, ectopic pregnancy cannot be excluded” should be a thing of the past. Diagnosis of EP should be based upon the positive identification of an adnexal mass using TVS rather than the absence of an intra‐uterine gestational sac. A systematic approach to scanning the early pregnancy pelvis will diagnose the vast majority of EPs at the initial scan. Ultrasound, and in particular TVS, is fast becoming the new gold standard for diagnosis of all types of EP. In modern management, laparoscopy should be seen as the operative tool of choice while TVS the diagnostic tool of choice.

OP24.03: Value of preoperative ultrasound examination in the selection of women with adnexal masses for laparoscopic surgery

equipped with an X7 matrix array transducer (2–7 MHz) and a custom designed RF interface (sampling frequency 32 MHz) in biplane mode. The displacement of the fetal aortic wall can be estimated accurately by finding the maximum of the cross correlation function of two consecutive wall reflections. Based on the sampling frequency, the resolution of wall displacement in the direction of the ultrasound beam is 24 micrometers and is improved to a few micrometers by applying quadratic interpolation. By overlaying RF data relative to the tracked aortic wall a detailed mean wall reflection can be derived. Data analysis showed that the aortic wall reflection can be described by the sum of two Gaussian pulses with center frequency and the fractional bandwidth equal to those of the emit ultrasound pulse. An iterative algorithm that minimizes the sum of squared differences between the model-based and measured mean wall reflection was employed to fit the parameters of the model. Results: The mean IMT (N = 83, GA 22 to 38 wks) for the near and far wall in the longitudinal and cross sectional plane were 0.34 (+0.17), 0.34 (+0.17), 0.43 (+0.26) and 0.38 (+0.20) respectively and neither related with gestational age nor was statistically different from each other (Friedman test, P = 0.201). Conclusions: Fetal aortic intima media thickness, 0.4 mm as measured in this study is only a fraction of those reported in other published data, 1.90 mm and 1.15 mm in fetuses and newborns respectively as derived from caliper settings in B-mode images. The results presented here might indicate overestimation of B-mode derived fetal aortic IMT measurements in prior studies.

OP02.03: Pregnancies of unknown location: what influences outcome?

Objectives: To determine the variables associated with different outcomes for pregnancies of unknown location (PUL). Methods: Prospective observational study. Women in the 1st trimester of pregnancy presenting to the early pregnancy unit (EPU), between 2009 and March 2011, underwent a transvaginal scan (TVS). A PUL was classified on TVS if there was no intraor extra-uterine pregnancy. Data was collected from women with a PUL at the first TVS. More than 10 historical, clinical and 3-D ultrasonographic end points were collected for analysis. Women were followed up until the outcome was established: failed PUL, intrauterine pregnancy (IUP) and ectopic pregnancy (EP). Off-line 3-D processing of the uterine and ovarian volumes was performed using VOCAL in order to calculate endometrial volume (EV), mean gray index, vascular index (VI), flow index (FI) and vascular flow index (VFI). Univariate analysis was performed in order to establish the significant variables for the different PUL outcomes (ANOVA F-test and Fisher’s exact test). Results: 154 women were initially classified as a PUL. 143 women were included in the final analysis (11 cases lost to follow up). 69.2% (99/143) failed PULs, 23.1% (33/143) IUPs and 7.7% (11/143) EPs. The variables that were significantly associated with PUL outcomes were: gray index (P = 0.01), flow index (P = 0.01), hCG at 48hrs (P = 3.13E-07), log hCG at 48hrs (P = 1.89E-09), and hCG ratio (P = 4.34E-16). Conclusions: 3-D volumetric indices of the uterus and ovary may be useful in the prediction of PUL outcome. These results could result in the development of new mathematical models in management of PULs.

OP29.09: Prediction of the need for morcellation at total laparoscopic hysterectomy (TLH) from pre-operative 3-D volumetric ultrasound-estimated uterine weight and parity: Oral poster abstracts

Objectives: To derive and validate an algorithm allowing estimation of uterine dry weight from maternal characteristics and pre-operative 3-D uterine volume ultrasound evaluation in women undergoing TLH. Methods: This is an ongoing prospective study on women undergoing TLH. Data collected includes patient age, parity, height, weight, 3-D ultrasound estimated uterine volume, operative blood loss and dry weight as measured by our pathology service. Uterine volumes were analyzed using virtual organ computer-aided analysis (VOCAL), manually calculated in the longitudinal plane with 30 degree rotation steps. A prediction model was developed using multiple regression analysis to predict uterine dry weight. Results: total of 41 cases had complete data suitable for testing of this algorithm. The mean age was 45.5 years (SD 6.4), the ultrasound estimated volumes ranged from 26.4 ml to 1507 ml. The correlation coefficient between ultrasound volumes and dry weight was 0.98. The weight estimation formula was: Uterine weight (g) = 1979.1+1.03 × Uterine volume −10.3*Age −9.2 × Height. The 95% CI for prediction errors was −109 g to 308 g. Morcellation was required in 16/41 cases. The sensitivity, specificity, positive predictive value and negative predictive value for this algorithm to predict the need for morcellation were: 100%, 48%, 57% and 100% respectively. The algorithm was correct in predicting the need for morcellation for all of these cases. It predicted morcellation for 12 cases that did not require the procedure. The overall accuracy of the method was 71%. Conclusions: Uterine weight can be estimated from 3D ultrasound and patient characteristics with a high degree of accuracy. Comparison with traditional ellipsoid uterine volume estimation is now required. The need for morcellation at TLH can be predicted before surgery with a fair degree of accuracy.

OP02.01: The comparison of power Doppler colour scores and volume of retained products of conception in a woman with incomplete miscarriage: prediction of successful expectant management

Objectives: To assess the evolution of hypoplastic left heart syndrome (HLHS) suspected at 11–14 weeks, and to evaluate the impact of the NT on predicting outcome. Methods: Retrospective study comparing the findings and natural progression of 5 cases of HLHS suspected at 11–14 weeks. All scans were performed by a single sonologist certified by the Fetal Medicine Foundation. Fetuses suspected of having HLHS were referred to pediatric cardiology. The 5 cases were compared with respect to NT, presence of other structural/cardiac findings, karyotype (when available), final diagnosis and outcome. Chi-square test was used in the analysis. Results: There were 5 fetuses confirmed of having HLHS. Of those 2 (40%) elected termination at 15w0d and 21w6d, and 2 (40%) had spontaneous in utero demise at 14w2d and 18w0d. All 4 had an NT > 3 mm. The 5th case had a normal NT of 2.2 mm and evaluation at 2 week intervals demonstrated a decrease in the atrioventricular disproportion (AVD), a persistent left superior vena cava (LSVC) and a suspected dilated coronary sinus versus an atrioventricular (AV) canal. The fetus was delivered at term and the final diagnosis was an AV canal, persisting LSVC and a dysplastic mitral valve. The NT was highly predictive of the outcome in the 5 cases: the higher the NT the higher the chance for in utero demise. In the one case with a normal NT (20%), there was normalization of the AVD and a favorable neonatal outcome. Even though our sample size was very small, having an NT < 3 mm was associated with a favorable outcome (P = 0.025). Conclusions: In this small cohort of patients, our study emphasizes the varied outcome of HLHS suspected at 11–14 weeks with 40% ending with spontaneous in utero demise and 20% having a favorable outcome. As has been previously shown, the larger the NT, the worse the fetal prognosis and the higher the chances of spontaneous demise. This may lessen the burden on those families electing to terminate. Whenever HLHS is encountered with a normal NT, caution must be exercised without haste in offering termination.

The term “pregnancy of unknown location” is here to stay

The term “pregnancy of unknown location” is an ultrasound classification and not a final diagnosis. The use of this terminology is here to stay and should continue as long as there is an appreciation for what it really means. It is the responsibility of the clinician, who follows up these women with a PUL, to ensure that a final diagnosis is achieved while preserving the well‐being of these women.