Sanger J R, Kolachalam R, Komorowski R A, Yousif N J, Matloub H S
Department of Plastic and Reconstructive Surgery, Medical College of Wisconsin, Milwaukee.
Plast Reconstr Surg. 1992 May;89(5):931-40; discussion 941-2.
The effect of silicone gel on the peripheral nerve was studied in Sprague-Dawley rats. Silicone gel was placed either extraneurally (N = 36) adjacent to or injected directly in the sciatic nerve (N = 20). Nerve histology was studied every 2 weeks over a 20-week period. Extraneural silicone gel elicited an intense inflammatory response characterized initially by predominantly histiocytes with a few eosinophils, lymphocytes, and foreign-body giant cells. The cellular response peaked at 4 weeks, after which time collagen deposition increased and the thickness of the cellular infiltrate surrounding the gel decreased. The gel was temporarily contained by the inflammatory response, but throughout the time course of the study, gel migration and breakup into smaller droplets occurred. Each droplet appeared to initiate the inflammation-fibrosis cycle anew. Perineural fibrosis was marked by 20 weeks, but there was no penetration of the epineurium by the gel. Intraneurally injected silicone gel also caused a delayed, but similar inflammatory response, eventually followed by fibrosis surrounding the gel. Intraneural gel tended to remain in larger droplets and did not migrate over the duration of this study. No direct evidence of gel toxicity to peripheral nerves was observed in either the extraneural or intraneural gel groups despite the initial intense inflammatory response and subsequent fibrosis.
在斯普拉格-道利大鼠中研究了硅胶对周围神经的影响。将硅胶置于神经外（N = 36），紧邻坐骨神经或直接注入坐骨神经（N = 20）。在20周的时间内，每2周研究一次神经组织学。神经外硅胶引发了强烈的炎症反应，最初主要表现为组织细胞，伴有少量嗜酸性粒细胞、淋巴细胞和异物巨细胞。细胞反应在4周时达到峰值，此后胶原沉积增加，凝胶周围细胞浸润的厚度减小。凝胶被炎症反应暂时包裹，但在整个研究过程中，凝胶发生迁移并分解成更小的液滴。每个液滴似乎又重新引发炎症-纤维化循环。20周时神经周围纤维化明显，但凝胶未穿透神经外膜。神经内注射硅胶也引起了延迟但类似的炎症反应，最终凝胶周围出现纤维化。神经内的凝胶倾向于保持较大的液滴状态，在本研究期间未发生迁移。尽管最初有强烈的炎症反应和随后的纤维化，但在神经外或神经内凝胶组中均未观察到凝胶对周围神经有毒性的直接证据。
