探讨卵圆孔的形态、外口的大小对半月神经节球囊压迫术（PMC）操作的影响。

纳入南京大学医学院附属鼓楼医院神经外科自2017年1月至2018年6月收治的382例原发性三叉神经痛（TN）患者，术前均行颅底CT薄层扫描，3D重建后，从穿刺方向观察卵圆孔形态，并测量卵圆孔外口面积，结合术中穿刺结果评价卵圆孔形态、外口大小对手术的影响。

卵圆孔穿刺后，球囊置入Meckel’s腔内并呈现典型"梨形"显影即为成功，纳入成功组；卵圆孔穿刺失败或卵圆孔穿刺成功，但球囊未能成功置入Meckel’s腔、未能典型"梨形"显影即为失败，纳入失败组。成功组356例（93.19%），卵圆孔呈椭圆形324例（91.01%），外口面积范围23.42~34.23 mm²，中位面积为30.27 mm²；卵圆孔呈圆形32例（8.99%），外口面积范围24.15~33.00 mm²，中位面积为30.15 mm²。失败组26例（6.81%），其中卵圆孔穿刺失败1例，Meckel’s腔穿刺失败25例；卵圆孔外口呈椭圆形20例（76.92%），外口面积范围11.67~48.84 mm²，中位面积为24.15 mm²；卵圆孔外口呈圆形6例（23.08%），外口面积范围14.38~43.51 mm²，中位面积为25.40 mm²，失败组中虽有1例外口面积为48.84 mm²，大于所有成功组病例，但失败组中位面积数显著小于成功组（P<0.05）；失败组中卵圆孔外口呈现圆形的比例大于成功组（P<0.05）。1例卵圆孔穿刺失败患者的卵圆孔呈椭圆形，外口面积20.00 mm²，但卵圆孔内、外口成角，穿刺针不能通过。

半月神经节PMC的成功率较高，与卵圆孔相关的穿刺失败多与卵圆孔外口圆形、外口过小有关，少数与卵圆孔外口过大有关，特殊情况下，卵圆孔内、外口的折曲、成角也会导致手术失败。

To explore the effect of the shape of foramen ovale and the size of the external orifice on percutaneous microballoon compression (PMC) of the semilunar ganglion.

Three hundred and eighty-two patients with primary trigeminal neuralgia (TN) who admitted to the Neurosurgery Department of Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, from January 2017 to June 2018 were underwent thin-layer CT scanning of skull base before operations, then the images were reconstructed in three dimensions, the shape of foramen ovale was observed and the area of foramen ovale was measured from the direction of surgical puncture subsequently. Finally evaluate the effect of the shape of foramen ovale and the size of external orifice on the operations according to the results of intraoperative puncture.

According to the balloon was placed into Meckel’s cavity and showed a typical "pear shaped" imaging, which was regarded as successful and included in the successful group. The failure of foramen ovale puncture or the success of foramen ovale puncture, but the balloon failed to be placed into Meckel’s cavity and failed to show a typical "pear shaped" , which was regarded as failure and included in the failure group. There were 356 patients in the successful group, the success rate was 93.19%, the oval foramens look like oval in 324 cases (91.01%), and the areas of external orifice were 23.42-34.23 mm², the median area was 30.27 mm², oval foramens with round shape in 32 cases (8.99%), the areas of the external orifice were 24.15-33.00 mm², median area was 30.15 mm². There were 26 patients in the successful group, the failure rate was 6.81%. Among them, 1 failed case due to unsuccessful puncture of foramen ovale, the remaining 25 cases failed to Meckel’s capsule. Twenty cases (76.92%) with oval outer opening, and the areas were 11.67-48.84 mm², the median area was 24.15 mm² in this group, otherwise 6 cases(23.08%) with round outer opening, their areas were 14.38-43.51 mm², the median area was 25.40 mm². Although there was one patient in the failure group with an orifice area of 48.84 mm², which was larger than all cases in the successful group, but the number of median areas in the failure group was significantly smaller than the successful puncture group (P<0.05). The proportion of circular external orifice of foramen ovale in the failure group was larger than successful group (P<0.05). One special case with oval-likely foramen ovale was failed to puncture the foramen ovale, the area of external orifice was 20.00 mm², but the inner and outer part of the foramen ovale were angled, and the puncture needle couldn’t pass through.

The success rate of puncture in the treatment of TN by PMC is very high, the reasons of failure related to foramen ovale were mostly due to the small external area and round shape of foramen ovale, and a few related to the large external diameter of foramen ovale. In special cases, the folding and angulation of the internal and external part of foramen ovale would also lead to the failure of operation.