The Division of Rhinology, Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, California 94305, USA.
Am J Rhinol Allergy. 2009 Nov-Dec;23(6):591-6. doi: 10.2500/ajra.2009.23.3391.
Middle turbinate lateralization, adhesions, and inflammation are causes of suboptimal sinus patency following surgery. A bioabsorbable drug-eluting stent has been developed to maintain sinus patency while providing controlled steroid delivery to the sinus mucosa. The aim of this study was to characterize the in vivo drug delivery efficacy and tolerance of this stent in a rabbit model.
Bioabsorbable stents coated with mometasone furoate were placed bilaterally in the maxillary sinuses of 31 rabbits via dorsal maxillary sinusotomy. Animals were sacrificed between 5 days and 18 weeks postoperatively. Efficacy was assessed by measuring tissue concentrations of steroid in maxillary sinus and nasal mucosa and by measurement of plasma steroid concentrations. Tolerance was assessed by histological evaluation of the sinus mucosa at different time points.
Therapeutic mucosal drug concentrations were attained in a time-dependent fashion (range 175-28,189 ng/g). Plasma drug concentrations were generally near or below the lower limit of quantification (15 pg/mL). Histopathological examination of the mucosa showed no differences in the reaction to steroid-coated stents versus nondrug-coated control stents, with inflammation, epithelial ulceration, and bony reaction ranging from none to mild at all time points. Microscopic fungal hyphae were noted in a small proportion of both treatment and control sinuses, without evidence of associated adverse tissue reaction.
In a rabbit model, mometasone-coated bioabsorbable stents are able to provide local steroid delivery with negligible systemic absorption. Corticosteroid-eluting stents may prove useful following endoscopic sinus surgery in maintaining sinus patency and reducing inflammation.
中鼻甲偏曲、粘连和炎症是鼻窦手术后鼻窦通畅不佳的原因。已经开发出一种可生物吸收的载药洗脱支架，以保持鼻窦通畅，同时向鼻窦黏膜提供受控的类固醇输送。本研究的目的是在兔模型中表征该支架的体内药物输送效果和耐受性。
通过上颌窦经上颌窦切开术将载有糠酸莫米松的可生物吸收支架双侧放置在 31 只兔子的上颌窦中。动物在手术后 5 天至 18 周之间被处死。通过测量上颌窦和鼻黏膜中类固醇的组织浓度以及测量血浆类固醇浓度来评估疗效。通过在不同时间点对窦黏膜进行组织学评估来评估耐受性。
以时间依赖的方式达到了治疗性黏膜药物浓度（范围 175-28,189ng/g）。血浆药物浓度通常接近或低于定量下限（15pg/mL）。对黏膜的组织病理学检查显示，载药支架与非载药对照支架的反应没有差异，所有时间点的炎症、上皮溃疡和骨反应均从无到轻度不等。在一小部分治疗和对照鼻窦中都注意到了真菌菌丝的微观存在，但没有证据表明与组织反应有关的不良反应。
在兔模型中，糠酸莫米松涂层的可生物吸收支架能够提供局部类固醇输送，而系统吸收可忽略不计。在鼻内镜鼻窦手术后，皮质类固醇洗脱支架可能有助于保持鼻窦通畅并减少炎症。
