Abstract:
Experimental maxillofacial surgery is commonly performed in pigs; however, locoregional anesthesia of this area has not been described. This study evaluated the feasibility of a novel maxillary nerve block approach. In part I, cadavers were used to determine anatomic landmarks and assess maxillary nerve dye staining by using 0.03 mL kg-1 of a 1:10 mixture of commercial food dye and 0.5% bupivacaine. In part II, 10 additional pig cadavers underwent bilateral ultrasound-guided maxillary nerve blocks by using trans-infraorbital canal needle placement. The maxillary nerve was harvested and scored based on degree of staining (0 and 1, absent or incomplete staining; 2, staining; >1 cm circumferentially). Intracranial and intraconal spread of dye was evaluated. A Kruskal-Wallis test was used to compare infraorbital canal length estimated either externally via landmarks, internally via ultrasound, or actually measured after dissection. In 18 of 20 (90%) injections, successful staining (score = 2) of maxillary nerves was obtained for a nerve length of 2.4 ± 0.3 cm. Two of 20 cases (10%) had inadequate staining (score <2). At dissection of these 2 cases, the needle tip was observed to have collided with an unerupted tooth (third molar). No intracranial or intraconal spread of dye was observed. We detected no statistical differences between the estimated external, estimated internal, or actual dissection methods for measurement of infraorbital canal length (P = 0.3). Ultrasound-guided trans-infraorbital maxillary nerve block in pigs is a feasible technique, warranting further work to evaluate its in vivo efficacy and safety.
摘要:
实验性颌面手术通常在猪中进行;然而,尚未描述该区域的局部麻醉。本研究评估了一种新型上颌神经阻滞方法的可行性。在第一部分,尸体用于确定解剖标志,并通过使用0.03mLkg-1的商业食品染料和0.5%布比卡因的1:10混合物来评估上颌神经染料染色。在第二部分,通过使用经眶下管针放置,另外10只猪尸体接受了双侧超声引导的上颌神经阻滞。采集上颌神经并基于染色程度(0和1,不存在或不完全染色;2,染色;圆周>1cm)进行评分。评估染料的颅内和内扩散。使用Kruskal-Wallis测试来比较通过地标外部估计的眶下运河长度,内部通过超声波,或解剖后实际测量。在20次注射中的18次(90%),对于2.4±0.3cm的神经长度,获得了上颌神经的成功染色(评分=2)。20例中有2例(10%)染色不充分(评分<2)。在这两个病例的解剖中,观察到针尖与未萌出的牙齿(第三磨牙)碰撞。未观察到染料的颅内或内扩散。我们检测到估计的外部,估计内部,或实际解剖方法测量眶下管长度(P=0.3)。超声引导下猪经眶下上颌神经阻滞是一种可行的技术,保证进一步的工作,以评估其体内疗效和安全性。