微波子宫内膜去除术中组织热损伤的观察

Tissue injury observation caused by thermal effects of microwave endometrial ablation

目的探讨微波子宫内膜去除术(MEA)中热效应对组织结构的影响,寻求适宜的内膜薄化方法和微波作用方式。方法对离体和在体子宫分别行全面刮宫薄化内膜后的 MEA(刮宫组)和早卵泡期(未刮宫)直接 MEA(早卵泡期组)。术中将微波探头移动方式设为"Z"形和"Z+W"形两种方式,同时测量宫底、两侧宫角、子宫后壁及前壁下段的子宫浆膜面温度。并将作用后的子宫标本切片行 HE 染色、尼克酰胺腺嘌呤核苷酸-黄递酶(NADH-d)染色,光学显微镜(光镜)、电子显微镜(电镜)下观察组织热损伤后的形态学改变及损伤深度。结果 (1)光镜下见子宫内膜腺体扭曲、细胞界限消失,核浓染,间质中大量急性炎性细胞浸润;浅肌层细胞核固缩、浓染,胞质浓缩,细胞排列密集;深层肌细胞无改变。NADH-d 染色可见损伤后的子宫内膜层及部分浅肌层为无色区;宫壁组织热损伤的范围清晰可辨。电镜下坏死部分的平滑肌细胞核染色质、核膜、细胞膜被破坏;线粒体肿胀、膜破裂、嵴消失,细胞器被大量破坏;坏死与正常平滑肌移行区的平滑肌细胞核染色质轻度破坏;核膜及细胞膜存在,线粒体高度水肿,粗面内质网轻度扩张、脱颗粒。(2)离体子宫与在体子宫的最高温度均位于子宫后壁,分别为50.9℃和37.6℃,两者比较,差异有统计学意义(P<0.01)。(3)离体子宫的宫体组织热损伤深度为4.0～8.8 mm,颈体交界处为1.6～3.8 mm。在体子宫的宫体组织热损伤深度为4.1～6.6 mm,颈体交界处为0～2.8 mm。子宫后壁的损伤深度最深,与宫底、两侧宫角及前壁下段等部位比较,差异均有统计学意义(P<0.01)。离体子宫及在体子宫的对应部位之间损伤深度比较,差异均有统计学意义(P<0.05)。刮宫组和早卵泡期组的组织热损伤深度比较,差异无统计学意义(P>0.05);微波探头以"Z+W"形移动时,组织损伤深度明显深于"Z"形移动方式,两者比较,差异有统计学意义(P<0.05)。结论全面刮宫后和早卵泡期施行 MEA 均可有效去除子宫内膜,其热损伤深度可控。

Objective To investigate the thermal effects on tissue structures during microwave endometrial ablation （MEA） and seek a feasible method of endometrial thinning and a fitting mode of applicator radiating microwaves. Methods Operations were performed between the group of thorough uterine curettage and the group of early follicular phase in in vitro or in vivo uterus. The former was treated with MEA after thorough uterine curettage;while the latter was treated with MEA in the early follicular phase directly. The applicator radiating microwaves were moved in ＂Z＂ or ＂Z ＋ W＂ shape inside uterine cavity. At the same time the serosal temperature was measured in the uterine fundus, tael comua uteri, the posterior wall and the lower part of anterior wall. After operations the uterine specimens were stained by hematoxylineosin, and respiratory enzyme dehydronicotinamide adenine dinucleotide phosphate diaphorase （NADH-d） methods. The morphologic changes and the depth of tissue thermal damage were evaluated using an optical microscope and electron microscope. Results （ 1 ） Under the optical microscope the endometrial glands became distorted, the cell boundaries disappeared, the nucleoli turned condensed and were stained darker. A large number of acute inflammatory cells appeared in fibrous tissue. In the shallow muscle layer cells were arrayed thickly, nucleoli were solidified and condensed, and cellular plasm were concentrated. The endometrial and the superficial muscle layers were damaged and colorless with NADH-d staining. The scope of the tissue thermal damage was clearly seen. Under an electron microscope, some smooth muscle cells,chromatin, karyotheca and cellular membranes were destroyed. The mitochondria were swollen, membranes were ruptured, and the crista disappeared. Many organelles were destroyed. The chromatin was lightly wrecked in the transitional area between putrescence and the normal smooth muscle tissue. Karyotheca and cellular plasm still existed, the mitochondria were highly edematous and the crista were disappeared, and the granular endoplasmic reticula were slightly expanded and degranulated. （2） The serosal temperature in in vitro uterus was significantly higher than that in in vivo uterus （P 〈 0. 01 ）. However, the highest temperature in in vitro or in vivo uterus were all taken in the posterior wall, being 50.9 ℃ and 37.6 ℃ , respectively. （ 3 ） The injury depth in in vitro uterus was 4. 0 - 8. 8 mm in the uterine body, 1.6 - 3.8 mm in the cervix uteri-uterine body junction; while those of in vivo uterus were 4. 1 - 6. 6 mm, 0 - 2. 8 mm, respectively. The highest injury depth of tissue was in the posterior wall, significantly different from the other parts（ P 〈0. 01 ）. The injury depth of the corresponding part in in vitro or in vivo uterus all had a significant difference （ P 〈 0. 05 ）. The depth of thermal damage had no significant difference between the group of thorough uterine curettage and the group of early follicular phase（P 〉0. 05）. The injury depth of the ＂Z ＋ W＂ radiation group increased significantly than that of the ＂ Z＂ radiation group（ P 〈 0. 05 ）. Conclusions （1） The depth of thermal damage is safe and controllable. （2） MEA with preoperative thorough uterine curettage or scheduling treatment at the follicular phase is efficient. （3） h is the ideal performing mode that the applicator radiating microwaves move in ＂Z ＋ W＂ shape inside uterine cavity. （4） The thermal damage of MEA occurs more frequently in the portion with a shortage of blood supply.