Transrectal contrast-enhanced ultrasound-guided transperineal core-needle biopsy versus endoscopic forceps biopsy in the diagnosis of complex rectal lesions

Background: The preoperative pathological diagnosis of rectal lesions is crucial for formulating treatment plans. For subepithelial lesions (SELs) and larger lesions with necrosis of the rectum, endoscopic forceps biopsy (EFB) cannot provide an accurate pathological diagnosis in most cases. By comparing the efficacy and safety of transrectal contrast-enhanced ultrasound-guided transperineal core-needle biopsy (TRCEUS-TP-CNB) and EFB, this study explored the value of TRCEUS-TP-CNB in the diagnosis of complex rectal lesions, such as SELs.

Methods: A retrospective, cross-sectional study was conducted with 32 consecutive patients with complex rectal lesions admitted to our hospital from May 2016 to June 2022. Clinical, ultrasound, and pathological data were collected from these patients who underwent EFB followed by TRCEUS-TP-CNB.

Results: The success rate of EFB was 21.88% (7/32) and that of TRCEUS-TP-CNB was 93.75% (30/32). No significant complications were observed for either biopsy method. Factors affecting the success rate of EFB included the lesion width (cm) (1.90±0.62 vs. 4.26±2.40, P<0.001) and lesion thickness (cm) (1.29±0.51 vs. 2.96±1.75, P<0.001). The success rate of TRCEUS-TP-CNB was not affected by these factors. In the paired study of TRCEUS-TP-CNB and EFB, the times of samples per person (1 vs. 2.14±0.90, P=0.015), number of specimens per sample (8.27±1.93 vs. 3.31±1.67, P<0.001), lesion width (cm) (3.79±2.42 vs. 1.90±0.62, P=0.001), and lesion thickness (cm) (2.64±1.75 vs. 1.29±0.51, P=0.001) were the factors affecting the difference of the sampling success rate. In the SELs, the success rate of EFB was 10% (1/10) and that of TRCEUS-TP-CNB was 100% (10/10), and the difference between the two groups was statistically significant (P=0.004).

Conclusions: TRCEUS-TP-CNB is an effective biopsy method for complex rectal lesions. The success rate of EFB is lower in the larger lesions. Compared with EFB, TRCEUS-TP-CNB required fewer times of samples be taken and obtained more specimens. For larger lesions and SELs of the rectum, TRCEUS-TP-CNB is expected to become one of the preferred biopsy methods.