Weaver E M, Chaloupka J C, Putman C M, Roth T C, Horky J K, Sasaki C T
Department of Surgery, Yale University School of Medicine, New Haven, Connecticut, USA.
Laryngoscope. 1999 Jan;109(1):8-14. doi: 10.1097/00005537-199901000-00003.
The precise effects of therapeutic occlusion of the internal maxillary artery (IMA) on distal nasal mucosal perfusion are unknown. A better understanding of these effects has important implications regarding the rationale and expected efficacy of certain therapeutic interventions for epistaxis management. The authors developed an animal model to assess these issues.
The effects of "proximal" and progressively more "distal" occlusions of the IMA on nasal mucosal blood flow (NBF) were assessed in anesthetized swine using continuous laser Doppler flowmetry. The levels of arterial occlusion were selected to simulate clinical therapeutic occlusions used for the management of epistaxis.
Nineteen swine were entered into one of four experimental groupings: proximal IMA occlusion using platinum micro-coils (n = 6), mid-grade distal IMA occlusion with polyvinyl alcohol particulate (PVA) suspensions (300 to 500 microns, n = 5), high-grade distal IMA occlusion with polyvinyl alcohol particulate suspensions (50 to 150 microns, n = 5), and sham control (n = 2).
All embolizations resulted in acute decreases in average NBF from 120 mL/min per 100 g to 40 mL/min per 100 g (P < .05 for all groups). NBF returned to baseline in all three treated groups within 2 to 8 days after therapeutic embolization, depending on the level of occlusion (coils, 2 d; mid-grade PVA, 2-3 d; high-grade PVA, 8 d). Follow-up angiography showed recanalization and collateralization as possible methods of reestablishing NBF.
This study supports the rationale for performing distal IMA occlusion with transarterial particulate embolization, in order to provide a longer period of time of diminished NBF. This theoretically should promote hemostasis within an injured portion of the nasal mucosa by decreasing perfusion pressure within the capillary bed. However, the benefits of distal IMA embolization must be balanced against potential ischemic complications, as may be more commonly seen with high-grade particulate embolization.
上颌内动脉（IMA）治疗性闭塞对鼻远端黏膜灌注的确切影响尚不清楚。更好地了解这些影响对于某些鼻出血治疗干预措施的原理和预期疗效具有重要意义。作者建立了一个动物模型来评估这些问题。
使用连续激光多普勒血流仪，在麻醉的猪身上评估IMA“近端”和逐渐更“远端”闭塞对鼻黏膜血流（NBF）的影响。选择动脉闭塞水平以模拟用于鼻出血治疗的临床治疗性闭塞。
19头猪被纳入四个实验组之一：使用铂微线圈进行IMA近端闭塞（n = 6），使用聚乙烯醇颗粒（PVA）悬浮液进行中度远端IMA闭塞（300至500微米，n = 5），使用聚乙烯醇颗粒悬浮液进行高度远端IMA闭塞（50至150微米，n = 5），以及假手术对照组（n = 2）。
所有栓塞均导致平均NBF从每100克120毫升/分钟急性下降至每100克4毫升/分钟（所有组P < .05）。根据闭塞水平，所有三个治疗组的NBF在治疗性栓塞后2至8天内恢复到基线（线圈，2天；中度PVA，2 - 3天；高度PVA，8天）。随访血管造影显示再通和侧支循环是重建NBF的可能方法。
本研究支持通过经动脉颗粒栓塞进行远端IMA闭塞的原理，以便提供更长时间的NBF减少。理论上，这应通过降低毛细血管床内的灌注压力促进鼻黏膜受伤部位的止血。然而，远端IMA栓塞的益处必须与潜在的缺血性并发症相平衡，高度颗粒栓塞可能更常见这种并发症。
