Shiels W E, Kirks D R, Keller G L, Ryckman F R, Daugherty C C, Specker B L, Summa D W
Department of Radiology, Children's Hospital Medical Center, Cincinnati, OH.
AJR Am J Roentgenol. 1993 May;160(5):931-5. doi: 10.2214/ajr.160.5.8470606.
Hydrostatic enema reduction of intussusception in children has been replaced by pneumatic reduction in a number of institutions. Colonic perforation occurs in as many as 2.8% of enema reductions, and questions persist about the relative safety of enemas performed with air vs fluid. The objectives of this study were to investigate and compare the pathologic patterns of in vivo colonic perforation and fecal spillage in young pigs given air and hydrostatic enemas, with and without the Valsalva maneuver.
Colonic perforations were induced in 135 juvenile pigs. The pigs were divided into five groups, and enemas with air, barium, and water-soluble contrast material were given with and without the Valsalva maneuver to induce the perforations. During the enemas, the Valsalva maneuver was observed when the animals strained. In each animal, the enema was continued and pressure increased until a perforation was detected with fluoroscopy. Radiographic, gross, and histologic examinations of each animal were performed after perforations occurred. Differences in fecal spillage were noted, and the morphologic variations of the perforations and the surrounding tissue were determined.
Perforations with hydrostatic (barium, water-soluble) enemas occurred at approximately 120 mm Hg of pressure (average bag height, 57 in. [143 cm]). No significant variations were found between the type of material used for contrast or the use of the Valsalva maneuver. With air enemas, perforations occurred at a mean pressure of 108 mm Hg without the Valsalva maneuver and at 145 mm Hg with the Valsalva maneuver. Perforations during air enemas did not occur during the Valsalva maneuver (pressures as high as 270 mm Hg), but rather between Valsalva maneuvers. Hydrostatic enemas produced full-thickness tears that were larger than those induced by air enemas in all cases. Air enemas with and without the Valsalva maneuver produced partial-thickness tears in 45% and 10%, respectively, of the pigs. Fecal spillage was diffuse in all hydrostatic perforations. In air enemas, spillage was focal in 55% and 90%, respectively, and absent in 45% and 10%, respectively, of perforations produced with and without the Valsalva maneuver.
Our results suggest that air enemas are safer than liquid enemas. Perforations that occurred during air enemas were smaller and associated with less fecal spillage and peritoneal contamination. The Valsalva maneuver appears to prevent colonic perforation during air enemas.
在许多机构中，儿童肠套叠的水压灌肠复位法已被空气灌肠复位法所取代。灌肠复位中结肠穿孔的发生率高达2.8%，关于空气灌肠与液体灌肠的相对安全性问题依然存在。本研究的目的是调查和比较在有或没有瓦尔萨尔瓦动作的情况下，对幼猪进行空气灌肠和水压灌肠后体内结肠穿孔和粪便外溢的病理模式。
对135只幼猪诱导结肠穿孔。将这些猪分为五组，在有或没有瓦尔萨尔瓦动作的情况下，分别给予空气、钡剂和水溶性造影剂灌肠以诱导穿孔。在灌肠过程中，当动物用力时观察瓦尔萨尔瓦动作。在每只动物中，持续灌肠并增加压力，直到用荧光透视检测到穿孔。穿孔发生后，对每只动物进行放射学、大体和组织学检查。记录粪便外溢的差异，并确定穿孔及其周围组织的形态学变化。
水压（钡剂、水溶性）灌肠穿孔发生时的压力约为120 mmHg（平均袋高57英寸[143 cm]）。用于造影的材料类型或瓦尔萨尔瓦动作的使用之间未发现显著差异。空气灌肠时，在没有瓦尔萨尔瓦动作的情况下，穿孔发生时的平均压力为108 mmHg，在有瓦尔萨尔瓦动作的情况下为145 mmHg。空气灌肠时的穿孔并非发生在瓦尔萨尔瓦动作期间（压力高达270 mmHg），而是发生在瓦尔萨尔瓦动作之间。在所有情况下，水压灌肠导致的全层撕裂比空气灌肠引起的撕裂更大。有和没有瓦尔萨尔瓦动作的空气灌肠分别在45%和10%的猪中导致了部分厚度的撕裂。在所有水压灌肠穿孔中，粪便外溢是弥漫性的。在空气灌肠中，有和没有瓦尔萨尔瓦动作时产生的穿孔分别有55%和90%的粪便外溢是局灶性的，分别有45%和10%的穿孔没有粪便外溢。
我们的结果表明，空气灌肠比液体灌肠更安全。空气灌肠时发生的穿孔较小，粪便外溢和腹膜污染较少。瓦尔萨尔瓦动作似乎可预防空气灌肠时的结肠穿孔。
