Diagnostic yield of transvaginal ultrasonography versus saline: infused sonohysterography in the evaluation of post-cesarean section uterine niche

Background: Caesarean section (CS) defects, also known as niches, refer to the discontinuity in the myometrium at the site of a previous CS. These niches pose a complication in over 50% of CS performed on Egyptian women. The primary method used to diagnose uterine niches is transvaginal ultrasound (TVU). In recent times, the use of TVU with saline- infused sonohysterography (SISH) has significantly improved the detection of uterine niches. Our objective was to assess the diagnostic performance of SISH compared to TVU in diagnosing uterine niches among non-pregnant women with previous cesarean sections (CS), by integrating the findings and demographic features of the participants.

Methods: For this purpose, we conducted a cross-sectional study involving 60 non-pregnant women with a history of CS but without any known systemic cause. Each participant underwent TVU followed by SISH. We recorded and analyzed the dimensions (depth, length and width) of the niche, as well as the residual myometrial thickness (RMT) adjacent to the niche in both TVU and SISH. Additionally, we collected data on the patients' age and the number of previous CSs.

Results: Our results showed that women with a CS niche detected by SISH had a significantly lower age compared to those detected by TVU. We also found a significant association between the number of previous CSs diagnosed by either TVU or SISH and the rate of CS niche detection, which increased with an increasing number of previous CSs. Furthermore, there was a significant difference in the depth, width, and residual myometrial thickness adjacent to the niche between the two procedures. All niche dimensions were significantly higher among women examined by SISH.

Conclusion: Our study confirms that SISH is a superior tool for assessing uterine niches in non-pregnant women with a history of CS compared to TVU. Furthermore, the combined approach of using both SISH and TVU eliminates the need for costly hysteroscopy.