Clinical Unit of Anesthesiology and Perioperative Intensive-Care Medicine, Department for Small Animals and Horses, Vetmeduni Vienna, Vienna, Austria.
Institute of Topographic Anatomy, Department of Pathobiology, Vetmeduni Vienna, Vienna, Austria.
PLoS One. 2021 Mar 10;16(3):e0248131. doi: 10.1371/journal.pone.0248131. eCollection 2021.
Transversus abdominis plane (TAP) block is a regional anesthetic technique used to desensitize the abdominal wall in several species. This study aimed to describe the anatomical characteristics of the abdominal wall and to identify a feasible approach for an US-guided TAP injection that would result in adequate staining of the relevant nerves in the abdominal wall in pig cadavers. Fresh cadavers from five Landrace pigs (age, 12 weeks; body weight, 35.5 ± 1.6 kg) were used. One pig (n = 1) was anatomically dissected, and four pigs (n = 4; i.e., 8 hemiabdomens) were used for TAP injections and evaluation of dye spread. The volume of 0.3 mL/kg/injection point of methylene blue was injected bilaterally. In the caudal retrocostal approach, the injection was performed ventral to the most caudal part of the costal arch. In the lateral approach, the injection was performed between the last rib and iliac crest. A needle was inserted in plane for the caudal retrocostal and the lateral approach caudocranially and craniocaudally, respectively. Successful staining was defined as presence of dye on the nerve for a length of >1 cm in its entire circumference. The TAP was found between different muscle layers in the described anatomical regions. In the caudal retrocostal approach the TAP was found between the external abdominal oblique and transversus abdominis muscle bellies. In the lateral approach the TAP was found between the internal abdominal oblique and transversus abdominis muscles. The approach combining lateral and caudal retrocostal injections at the studied volume stained a median of 5 (3-6) target nerves from the fourth-last thoracic nerve to L2 (six nerves). Combined caudal retrocostal and lateral TAP injections of 0.3 mL/kg/injection point, resulted in staining of target nerve branches which supply the periumbilical and caudal abdominal wall in pig cadavers.
腹横肌平面（TAP）阻滞是一种用于使几种物种的腹壁脱敏的区域麻醉技术。本研究旨在描述腹壁的解剖特征，并确定一种可行的超声引导 TAP 注射方法，以便在猪尸体中使相关神经在腹壁得到充分染色。使用来自 5 头长白猪（年龄 12 周；体重 35.5±1.6kg）的新鲜尸体。对 1 头猪（n=1）进行解剖，对 4 头猪（n=4；即 8 个半侧腹部）进行 TAP 注射和染料扩散评估。双侧注射 0.3mL/kg/注射点的亚甲蓝。在尾侧肋后入路中，注射在肋弓最尾端的腹侧进行。在外侧入路中，注射在最后一根肋骨和髂嵴之间进行。对于尾侧肋后入路和外侧入路，分别在头侧和尾侧将针插入平面。成功染色定义为神经上的染料长度>1cm，且沿其整个周长存在染料。TAP 位于描述的解剖区域的不同肌肉层之间。在尾侧肋后入路中，TAP 位于腹外斜肌和腹横肌肌腹之间。在外侧入路中，TAP 位于腹内斜肌和腹横肌之间。在研究的体积下，联合外侧和尾侧肋后入路注射可从第四对胸神经到 L2（共 6 对神经）染色 5（3-6）条目标神经。0.3mL/kg/注射点的联合尾侧肋后入路和外侧 TAP 注射可使猪尸体的脐周和尾侧腹壁的目标神经分支染色。
