Herman R M, Berho M, Murawski M, Nowakowski M, Ryś J, Schwarz T, Wojtysiak D, Wexner S D
Jagiellonian University Medical College, Krakow, Poland.
Colorectal Dis. 2015 May;17(5):433-40. doi: 10.1111/codi.12874.
Nonablative radiofrequency (RF) sphincter remodelling has been used to treat gastro-oesophageal reflux disease (GERD) and faecal incontinence (FI). Its mechanism of action is unclear. We aimed to investigate the histomorphological and pathophysiological changes to the internal and external anal sphincter (IAS and EAS) following RF remodelling.
An experimental FI model was created in 12 female pigs: eight underwent RF 6 weeks following induction of FI (FI+RF) and four were untreated (UFI). Four animals served as controls (CG). Two blinded pathologists examined all haematoxylin and eosin and trichrome stained slides.
Compared with the UFI group, histological examination of the IAS in the FI+RF group demonstrated an increased smooth muscle (SM)/connective tissue ratio (77.2 vs 68.1%, P < 0.05) and increased collagen I compared with collagen III content (67.2 vs 54.9%, P < 0.001). The RF+FI group exhibited greater SM bundle thickness compared with the UFI group (SM width 486.93 vs 338.59 μm, P < 0.01; height 4384.4 vs 3321.0 μm, P < 0.05). The EAS of the FI+RF animals showed a significantly higher type I/II fibre ratio (33.5 vs 25.2%, P = 0.023) and fibre type I diameter (67.2 vs 59.7 μm, P < 0.001) compared with the UFI group. Post-RF manometry showed higher basal (18.8 vs 0 mmHg, P < 0.001) and squeeze (76.8 vs 12.4 mmHg, P < 0.05) anal pressures. After RF treatment, the number of interstitial cells of Cajal was significantly reduced compared with the UFI and CG groups [0.9 (FI+RF) vs 6.7 (UFI) vs 0.7 (CG) per mm(2) , P < 0.001].
In an animal model nonablative RF appeared to induce morphological changes in the IAS and EAS leading to an anatomical state reminiscent of normal sphincter structure.
非消融性射频（RF）括约肌重塑已被用于治疗胃食管反流病（GERD）和大便失禁（FI）。其作用机制尚不清楚。我们旨在研究射频重塑后肛门内括约肌和外括约肌（IAS和EAS）的组织形态学和病理生理学变化。
在12只雌性猪中建立实验性大便失禁模型：8只在诱导大便失禁6周后接受射频治疗（FI+RF），4只未接受治疗（UFI）。4只动物作为对照（CG）。两名盲法病理学家检查所有苏木精-伊红和三色染色切片。
与UFI组相比，FI+RF组IAS的组织学检查显示平滑肌（SM）/结缔组织比率增加（77.2%对68.1%，P<0.05），I型胶原与III型胶原含量相比增加（67.2%对54.9%，P<0.001）。与UFI组相比，RF+FI组的SM束厚度更大（SM宽度486.93对338.59μm，P<0.01；高度4384.4对3321.0μm，P<0.05）。与UFI组相比，FI+RF动物的EAS显示I/II型纤维比率显著更高（33.5%对25.2%P=0.023），I型纤维直径更大（67.2对59.7μm，P<0.001）。射频治疗后测压显示基础肛门压力（18.8对0mmHg，P<0.001）和挤压肛门压力（76.8对12.4mmHg，P<0.05）更高。射频治疗后，与UFI组和CG组相比，Cajal间质细胞数量显著减少[每平方毫米0.9（FI+RF）对6.7（UFI）对0.7（CG），P<0.001]。
在动物模型中，非消融性射频似乎会引起IAS和EAS的形态学变化，导致一种让人联想到正常括约肌结构的解剖状态。
