下颌舌骨神经与面神经吻合的应用解剖

目的　为确保面神经与下颌舌骨神经顺利吻合提供参考。方法　在 2 5具 (5 0例 )尸头上解剖观察了下颌舌骨神经在颌下的走行、分支及双侧分支吻合情况。结果　下颌舌骨神经从下齿槽神经分出后在下颌舌骨沟内至下颌骨下缘处为第一段。从下颌骨下缘向前行至第一次分支为第二段 ,其长度为 13.6 1± 3.0 9mm ,直径为 1.2 1± 0 .14mm。从第一次分支后分别至二腹肌前腹与下颌舌骨肌的各分支为第三段 ,其中至二腹肌前腹支长度为 13.0 7±2 .49mm ,直径为 1.0 3± 0 .12mm ,至下颌舌骨肌支长度为 11.2 1± 1.75mm ,直径为 1.0 4± 0 .11mm。两侧之间有吻合。结论　该神经易于暴露 ,走行及分支均较恒定。适合于进行神经吻合。     

颞骨内面神经水平段的显微解剖

目的 研究颞骨内面神经水平段及其毗邻结构的显微解剖,为临床应用提供解剖学资料. 方法 通过模拟l临床经乳突入路的手术方法,分层解剖20个成人湿头颅标本(40侧颞骨),显露并观测颞骨内面神经水平段及其毗邻结构. 结果 面神经水平段的长度为[(8.85±1.01)(7.10～11.25)]mm、直径为[(1.88±0.65)(1.55～1.90)]mm;FN水平段与垂直段的夹角(向前)为[(115.5±6.89)(109.5～128.6)°;面神经水平段与鼓室天盖的夹角(向后)为[(28.5±3.66)(25.8～31.5)°;匙突至面神经水平段的垂直距离为[(1.89±0.58)(0.90～3.05)]mm;镫骨头至面神经水平段(垂直距离)为[(2.30±0.85)(1.97～3.11)]mm;锥曲段顶点到砧骨短脚尖的距离为[(2.55±0.21)(2.10～2.90)]mm;锥曲段顶点至外半规管隆突距离为[(2.86±0.31)(2.23～3.56)]mm;未发现面神经水平段有分支的或者移位的情况.面神经水平段的远段位于水平半归管隆突的前内侧.有2侧(2/40)水平段的远段位于外半规管隆突外侧0.89 mm和1.02 mm,占5%. 结论 膝状神经节、匙突、镫骨、鼓室天盖、水平半规管、砧骨是手术中确定FN水平段的重要标志.颞骨内面神经水平段与其毗邻结构的空间位置关系复杂,手术操作必须熟悉面神经水平段上述定位标志,以免损伤面神经.     

乳突手术中如何定位与辨认面神经易损伤段的探讨

目的 探讨乳突手术中面神经易损伤段的定位与辨认. 方法 对我科2010年5月至2012年9月收治的97例乳突根治术或乳突根治术加鼓室成型术治疗的慢性化脓性中耳炎的病例进行回顾性分析,对手术中定位、辨认面神经易损伤段的方法进行总结. 结果 ①97例中发现1例面神经骨管的先天性缺损.②联合或者部分依靠外半规管隆突、砧骨短脚、匙突、鼓室天盖、镫骨作为解剖标志成功定位、辨认出面神经水平段97例.③依靠外半规管隆突和砧骨短脚或者单独依靠外半规管隆突作为解剖标志成功定位、辨认出面神经锥曲段97例.④联合或者部分依靠砧骨短脚、鼓索神经、锥隆起、外半规管隆突作为解剖标志成功定位、辨认出面神经垂直段近段97例. 结论 面神经易损伤区内的外半规管隆突、砧骨短脚、匙突、鼓室天盖、镫骨、锥隆起、鼓索神经是乳突手术中确定面神经易损伤段的重要标志.     

下颌舌骨神经与面神经吻合的应用解剖

目的为确保面神经与下颌舌骨神经顺利吻合提供参考.方法在25具(50例)尸头上解剖观察了下颌舌骨神经在颌下的走行、分支及双侧分支吻合情况.结果下颌舌骨神经从下齿槽神经分出后在下颌舌骨沟内至下颌骨下缘处为第一段.从下颌骨下缘向前行至第一次分支为第二段,其长度为13.61±3.09mm,直径为1.21±0.14mm.从第一次分支后分别至二腹肌前腹与下颌舌骨肌的各分支为第三段,其中至二腹肌前腹支长度为13.07±2.49mm,直径为1.03±0.12mm,至下颌舌骨肌支长度为11.21±1.75mm,直径为1.04±0.11mm.两侧之间有吻合.结论该神经易于暴露,走行及分支均较恒定.适合于进行神经吻合.     

面神经颅外段的走行分布及临床应用研究进展

面神经起于桥脑下部的面神经核，自茎乳孔出颅后称面神经颅外段。面神经是面部主要运动神经，支配包括颈阔肌的面部表情肌、茎突舌骨肌及二腹肌后腹。在颅外的行程中又因穿经腮腺而分为腮腺前段、腮腺内段和腮腺后段。     

以颞中静脉为标记定位面神经额支

目的 探讨除皱术中以颞中静脉为标记,定位面神经额支的方法,以预防损伤.方法 对12具防腐成人头部标本和2具新鲜成人灌注头部标本,进行显微解剖,观察颞中静脉与面神经额支的位置关系.结果 ①额支位于颞浅筋膜深面和颞深筋膜浅层之间的组织内;颞中静脉位于颞深筋膜浅、深层之间的颞浅脂肪垫内.有颧颞中静脉和颧颞侧静脉两个分支,收集眶周深层的静脉血,回流到颞浅静脉.与上、下睑静脉、眼静脉、睑外侧静脉形成交通.另外,与颞深静脉吻合,并借此与翼静脉丛相通.②在耳屏点与额骨颧突的连线上,颞中静脉的交点,距耳屏点的平均距离是(18.2±2.3)mm.颞中静脉与最近额支的距离是(9.3±4.3)mm;最远额支的距离是(23.5±3.6)mm.结论 在耳屏点与额骨颧突的连线上,距颞中静脉5.0～27.1mm的区域,是面神经额支所在的"危险区".     

采用多重标记物示踪化学去细胞异体神经修复大鼠面神经缺损

[目的]探索用荧光金、量子点、固蓝"三标"逆行示踪方法来评价化学去细胞异体神经移植修复大鼠面神经缺损后颊支、下颌缘支、颈支的再生及神经的物质运输功能。[方法]外科显微镜下解剖、分离出鼠的左侧颅外段面神经主干及各分支(颞支、颧支、颊支、下颌缘支、颈支),在出茎乳孔处离断面神经主干,分别在距该断点10 mm处离断5个分支,移植化学去细胞异体全面神经,术后2个月暴露面神经,在颊支、下颌缘支、颈支吻合口远端分别注射荧光金、量子点、固蓝,3 d后脑干取材,冰冻切片,并在荧光显微镜下观察脑干内3种示踪剂的分布情况。[结果]将发源于脑干的面神经核团进行冰冻切片,荧光显微镜下观察到被荧光金、量子点、固蓝标记的神经元分别显示出黄色、红色和蓝色。[结论]根据神经轴浆运输的原理,采用多种标记物示踪法评价异体神经移植修复面神经损伤后神经干及各分支连续性的恢复情况,操作简便,可靠易行,是一种理想的评价方法。     

SMAS分离除皱术防止面神经颈支损伤的解剖学研究

目的为面颈区SMAS分离除皱术防止面神经颈支损伤提供解剖学依据.方法在12例新鲜标本和8例防腐固定标本上,解剖观测了面神经颈支的走行、分布、毗邻,建立相关的坐标体系,并得出面神经颈支的体表定位的坐标参数,分析颈支的分布特点及预防其损伤的手术操作方法.结果在以下颌角后下方最凸点为原点o的坐标系中,左侧面神经颈支的坐标值为(14.0mm,28.6±4.1mm)、(10.0mm,6.2±2.7mm)、(6.0 mm,-6.8±3.0mm)、(2.0mm,-16.2±4.5mm)、(0.0mm,-1 8.0±3.5mm)、(-2.0mm,-21.8±4.2mm)、(-6.0mm,-28.0±3.4mm)、(-10.0mm,-32.4±4.3mm).右侧侧面神经颈支的坐标值为(-18.0mm,24.2±5.1mm)、(-14.0mm,10.2±4.5mm)、(-10.0mm,-0.1±4.3mm)、(-6.0mm, -9.8±5.4mm)、(-2.0mm,m-15.4±6.7m)、(0.0mm,-18.0±5.8mm)、(2.0mm,-1 9.8±5.6mm)、(6.0mm,-22.8±4.9mm)、(10.0mm,-26.0±6.2mm)、(14.0mm,-29.2±5.3mm)、(18.0mm,-31.8±5.7mm).结论临床医生熟悉面神经颈支的位置、走行,有利于减少SMAS分离除皱术对其的损伤.     

在16排螺旋CT图像上颅骨茎突的表现及临床意义

[目的]探讨16排螺旋CT图像后处理评价颅底茎突解剖的准确性,为临床诊断和治疗茎突综合征提供准确的活体解剖数据.[方法]100例茎突正常受检者行16排螺旋CT检查后,行多层面重建(MPR),曲面重建(CPR),三维表面遮盖显示(SSD),容积显示(VR)4种后处理.分别测量茎突长度、前倾角、内倾角,茎突-颈动脉管外口、茎突-颈静脉孔、茎突-茎乳孔、茎突-乳突、茎突-颈内动脉及茎突-颈内静脉的距离.[结果]茎突长度(24.51±3.05)mm,左侧茎突长度(24.33±3.15)mm,右侧茎突长度(24.69±2.95)mm;前倾角19.35°±2.92°,内倾角24.00°±4.07°.茎突-颈动脉管外口距离(8.53±2.45)mm,茎突-颈静脉孔距离(2.87±0.88)mm,茎突-茎乳孔距离(2.34±0.74)mm,茎突-乳突距离(17.23±1.85)mm.茎突-颈内动脉及茎突-颈内静脉的距离分别为(6.49±1.58)mm,(3.70±1.46)mm.[结论]16排螺旋CT后处理对茎突的活体解剖显示全面、准确,其中多层面重建及三维表面遮盖显示最有价值,可对活体茎突及其周围毗邻关系做出准确、全面的评价.     

副神经的显微解剖及其临床意义

目的为颈部手术提供有关副神经的解剖学资料。方法在手术显微镜下解剖10例(20侧)成人头颈部标本,重点观测上颈部副神经及其毗邻结构。结果①副神经穿出二腹肌后腹后下缘处距乳突尖(24．90±4．05)mm;②副神经进入胸锁乳突肌上部前缘深面时距乳突尖(30．11±4．30)mm,其中75％的枕动脉发出胸锁乳突肌支与之伴行, 穿入点处两者距离为(5．70±0．78)mm;③副神经走行于寰椎横突的前方。结论寰椎横突、二腹肌后腹后下缘及胸锁乳突肌上部前缘是寻找颈部副神经的三个标志,而枕动脉的胸锁乳突肌支对临床帮助不大。     

Vulnerability of the sympathetic trunk during the anterior approach to the lower cervical spine

STUDY DESIGN: Anatomic dissection and measurements of the cervical sympathetic trunk relative to the medial border of the longus colli muscle and lateral angulation of the sympathetic trunk relative to the midline on both sides were performed. OBJECTIVE: To determine the course and location of the sympathetic trunk quantitatively and relate this to the vulnerability of the sympathetic trunk during the anterior approach to the lower cervical spine. SUMMARY OF BACKGROUND DATA: The sympathetic trunk is sometimes damaged during the anterior approach to lower cervical spine, resulting in Horner's syndrome with its associated ptosis, meiosis, and anhydrosis. No quantitative regional anatomy describing the course and location of the sympathetic trunk and its relation to the longus colli muscle is available in the literature. METHODS: In this study, 28 adult cadavers were used for dissection and measurements of the sympathetic trunk. The distance between the sympathetic trunk and the medial borders of the longus colli muscle at C6 and the angle of the sympathetic trunk with respect to the midline were determined bilaterally. The distance between the medial borders of the longus colli muscle from C3 to C6 and the angle between the medial borders of the longus colli muscle also were measured. RESULTS: The sympathetic trunk runs in a superior and lateral direction, with an average angle of 10.4 +/- 3.8 degrees relative to the midline. The average distance between the sympathetic trunk and the medial border of the longus colli muscle is 10.6 +/- 2.6 mm. The average diameter of the sympathetic trunk at C6 is 2.7 +/- 0.6 mm. The length and width of the middle cervical ganglion were 9.7 +/- 2.1 mm and 5.2 +/- 1.3 mm, respectively. The distance between the medial borders of the longus colli muscle was 7.9 +/- 2.2 mm at C3, 10.1 +/- 3.1 mm at C4, 12.3 +/- 3.1 mm at C5, and 13.8 +/- 2.2 mm at C6, and the angle between the medial borders of the longus colli muscle was 12.5 +/- 4. 7 degrees. CONCLUSIONS: The sympathetic trunk may be more vulnerable to damage during anterior lower cervical spine procedures because it is situated closer to the medial border of the the longus colli muscle at C6 than at C3. The longus colli muscles diverge laterally, whereas the sympathetic trunks converge medially at C6. As the transverse foramen or uncovertebral joint is exposed with dissection or transverse severance of the longus colli muscle at the lower cervical levels, the sympathetic trunk should be identified and protected.     

The anatomical variations of the emergence routes of supraorbital nerve: A cadaveric study and systematic review

BackgroundKnowledge of the location of supraorbital nerve is essential to perform supraorbital endoscopic surgery, regional nerve block, and nerve decompression in the treatment of migraine. This study discusses the emergence routes of supraorbital nerve as well as a systematic literature review on previous anatomical studies. This comparative analysis will be beneficial for surgeons worldwide.MethodsThe study sample consisted of 19 cadavers with bilateral supraorbital nerve dissections. The emergence route of the nerve through either a notch or foramen was recorded. Additionally, the distance from midline, nerve branching patterns, and diameter of emergence routes were measured.ResultsOur findings showed an equal number of supraorbital emergence route between notch and foramen (42%) and demonstrated average distance from emergence route and facial midline 22.34 (3.05) mm in male and 23.58 ± 2.42 mm in female. Diameter of notch type is 3.97 (0.99) mm and 3.39 (1.09) mm in foramen type. Data from systematic review showed range of distance from emergence route to facial midline from 22.2 to 33.7 mm. East Asia population had significant shorter distance of supraorbital emergence route to facial midline than Middle Asia and Caucasian population.ConclusionThis study provides greater insight into the anatomic variations and supraorbital never course in an understudied minority population. Surgeons should be aware of this critical area and strive to minimize dissection to prevent iatrogenic nerve injury.     

Surface landmarks of the facial nerve trunk: a prospective measurement study

Background: Facial nerve identification and preservation is the key to safe parotidectomy in most clinical situations. Traditional approaches to the main trunk have depended solely on internal landmarks but localization may further be enhanced if data are avail­able on its position with reference to neighbouring external features. Methods: Prospective measurements were taken on a series of parotidectomy patients intraoperatively. Using that spot on the main trunk 10 mm proximal to its bifurcation as the reference point, the depth from the skin and its cranio‐caudal distance from the summit of the tragus were measured. Results: Thirty‐three patients were included, whose body mass index showed that they had average body build. The reference point nerve was 23.6 mm (SD = 5.1 mm) from the skin surface, and 18.8 mm (SD = 6.0 mm) caudal to the tragus. Conclusion: Measurements relating to the siting of the facial nerve trunk were obtained live at operation. This information should be helpful in the initial mobilization of the parotid gland from its posterior relations and in facilitating the classical internal landmarks in the 3‐D localization of the main trunk, thereby allowing quicker and safer parotidectomy.     

Non-traumatic elevation techniques of the hypoglossal nerve during carotid endarterectomy: a cadaveric study.

OBJECTIVE: Ligation and dissection techniques of sternocleidomastoid artery, vein, ansa cervicalis and posterior belly of digastric muscle were developed in a cadaveric study for achieving minimally invasive elevation of the hypoglossal nerve during carotid endarterectomy and were subsequently used in patient treatment. METHODS: Carotid bifurcations, the extracranial part of the hypoglossal nerve, the sternocleidomastoid artery and vein and neighboring neurovascular structures were studied on 10 formalin-fixed adult cadaver heads (20 sides) under the surgical microscope. Landmarks and measurements for identification of the sternocleidomastoid artery and vein are described. RESULTS: The distance between the hypoglossal loop and the carotid bifurcation was measured as 14.5 - 25.2 mm (mean: 19.24 mm). 30 % of 20 sides were determined to have a Zone II-type carotid bifurcation. In 33 % of the Zone-II-type bifurcations, a low-lying hypoglossal loop was demonstrated. The sternocleidomastoid artery begins 2.2 - 3.5 mm (mean: 2.94 mm) supero-posterior from the occipital artery after the crossing point between the occipital artery and the hypoglossal nerve. The sternocleidomastoid artery and vein complex was 17.1 - 21.5 mm (mean 18.47 mm) away from the carotid bifurcation and forms a right angle with the descending hypoglossal nerve. The contribution of the sternocleidomastoid branch of the occipital artery always reaches the middle parts of the sternocleidomastoid muscle. CONCLUSION: Carotid endarterectomy through having knowledge of the normal and variable trajectories of the structures can almost always be accomplished as a safe procedure when appropriate maneuvers are applied. Dissection and ligation of the sternocleidomastoid artery, vein, ansa cervicalis and posterior belly of digastric muscle are very simple but effective techniques to obtain adequate exposure either for safe arterial reconstruction or to diminish the necessity for more complicated technical procedures.     

Easy and Safe Method for Facial Nerve Identification in Parotid Surgery

Background A safe and easy anatomical landmark is proposed to identify the facial nerve in parotid surgery. The facial nerve forms the center point between the base of the styloid process and the origin of the posterior belly of the digastric muscle. Objective To evaluate the consistency, accuracy, and safety of the landmark in identifying the facial nerve. Methods The study was designed in three steps: a cadaver study, a radiologic study, and a prospective clinical study. Anatomy was initially studied in two cadavers. Then the images of 200 temporal styloid regions were studied for consistency of the presence of the styloid base. In the second part of the radiologic study, the distance between the styloid base and the origin of the posterior belly of the digastric muscle was studied in 50 parotid regions. The clinical study involved 25 patients who underwent parotidectomy. Results The styloid base was present in all the images studied. The mean distance between the styloid base and the origin of the posterior belly of the digastric was found to be 0.72 cm (range: 0.45–0.99 cm). The facial nerve could be identified consistently and safely in all patients. Conclusion This trident landmark provided safe, accurate, and easy identification of the facial nerve using two fixed bony landmarks.     

带耳大神经的胸锁乳突肌肌瓣在腮腺癌手术修复中的应用

目的探讨腮腺深叶癌根治手术切除后,面部凹陷畸形及面神经缺损进行功能性修复的新方法,并评价临床疗效。方法对12例腮腺深叶癌侵袭周围骨质的患者,采取开放面神经管,将癌瘤、腮腺、受累面神经及周围骨质(包括乳突、茎乳孔、茎突及下颌升支后缘)扩大切除,利用面神经管内段正常的神经干断端与胸锁乳突肌肌瓣相连的耳大神经进行吻合,同时利用胸锁乳突肌肌瓣填充凹陷畸形。结果开放面神经管利用耳大神经胸锁乳突肌肌瓣功能性修复的方法,9例腮腺区凹陷畸形明显恢复常态,2例因肿瘤复发再次手术切除留有明显凹陷畸形,1例因局部感染,组织液化,肌肉萎缩,出现凹陷。面神经功能完全恢复,恢复时间最短为12周,最长20周,平均163周。同时提高了肿瘤的局部控制率。结论开放面神经管腮腺癌根治术,用耳大神经-胸锁乳突肌肌瓣即时修复,既达到了面部凹陷畸形的整复,又实现了面神经的功能性修复,同时减少肿瘤的局部复发,符合功能外科修复的发展要求,是一种临床应用效果比较理想的方法。     

肘部和前臂段桡神经解剖特征及损伤修复

目的 观察肘部和前臂段桡神经的解剖学特征及损伤修复的方法.方法 36侧成人上肢标本,于肘外侧做"S"形切口,从肱肌和肱桡肌间隙内解剖出桡神经肘段,沿桡神经干向远端追踪,找出桡神经深支出旋后肌的各个分支,测量深支各肌支的发出点、入肌点距肱骨髁上水平的距离和长度.逆行分离各分支,观察各分支的神经纤维在桡神经干内的分布定位特征.对12例肘部桡神经损伤的患者,采用桡神经定位缝合和不定位缝合的方法进行修复.结果 12例获得平均2.4年的随访.根据桡神经深支支配的运动区肌腱肌力恢复情况,神经定位缝合6例,术后有效率为83.3%.非定位缝合6例,有效率为50.0%.桡神经定位缝合组的有效率明显高于不定位缝合组.结论 前臂背侧距肱骨外上髁10～15cm范围内的锐器伤,伸拇困难者应考虑有骨间背神经肌支的损伤.运动支的神经纤维在桡神经干的内侧,对肘部桡神经断裂伤修复时重点应缝合内侧部分.显微定位缝合技术修复肘部和前臂段桡神经损伤是有效的方法.     

Direct coaptation of extensive facial nerve defects after removal of the superficial part of the parotid gland: an anatomic study

BACKGROUND: In the surgical repair of facial nerve paralysis, a tension-free end-to-end coaptation of the trunk or its branches with or without rerouting is functionally superior to grafting. Assuming that a lengthening of all branches of the parotid plexus can be attained by removal of the superficial part of the parotid gland and mobilization of the branches, we performed an anatomic study. METHODS: The parotid regions of 10 cadavers were dissected to investigate the length gained for the branches of the parotid plexus by this technique. Every branch at the upper and ventral border of the gland was marked by a surgical suture. After removing the superficial part of the parotid gland, the branches were cut at the suture, and the proximal stump was drawn toward the distal stump. The distance of the overlapping stumps was measured by means of an electronic gliding caliper. In addition, in five specimens only the trunk of the facial nerve was dissected by the same method, and the distance of the overlapping stumps was measured. RESULTS AND CONCLUSIONS: The results demonstrate that removing the superficial part of the parotid gland may be sufficient to enable direct coaptation without nerve grafting. Cut temporal or zygomatic branches with a gap of up to 15 mm and cut buccal or marginal mandibular branches with a gap of up to 23 mm can be bridged by mobilization of just the proximal stumps. This technique may also be used to bridge a 17-mm gap of the trunk of the facial nerve.     

A simple method for safe identification of the facial nerve using palpable landmarks

HYPOTHESIS: External palpable landmarks can be used to identify the facial nerve trunk quickly and safely. DESIGN: Prospective anatomical dissection study. SETTING: University department of human anatomy and university hospital. METHODS: A total of 40 human cadaver heads (79 facial nerves) were dissected by 2 prosectors, a surgeon with experience in the anatomy of the parotid region (J.A.P.; n = 39) and a medical student with experience in anatomical dissection and basic knowledge of the facial nerve disposition (A.M.; n = 40). A 3-cm skin incision was made in the center of the triangle formed by the temporomandibular joint, the mastoid process, and the angle of the mandible, and dissection was continued deep until the main facial nerve trunk was identified. MAIN OUTCOME MEASURES: The time taken from the skin incision to the identification of the nerve was monitored with a chronometer by an independent observer. The distance between the predicted and actual position of the facial nerve was measured. RESULTS: In all cases, the facial nerve was identified and there were no significant differences in the dissection time between the 2 prosectors (144 vs 148 seconds). The mean distance between the predicted and the actual position of the nerve was 1.42 mm. CONCLUSION: The proposed localization landmarks allowed a fast and safe identification of the facial nerve and may be of significant help during surgery around the parotid region.     

Transzygomatic-Subtemporal Approach for Middle Meningeal-to-P2 Segment of the Posterior Cerebral Artery Bypass: An Anatomical and Technical Study.

We evaluated the use of a bypass between the middle meningeal artery (MMA) and P2 segment of the posterior cerebral artery (PCA) as an alternative to an external carotid artery (ECA-to-PCA) anastomosis. Five adult cadaveric heads (10 sides) were used. After a temporal craniotomy and zygomatic arch osteotomy were performed, the dura of the floor of the middle cranial fossa was separated and elevated. The MMA was dissected away from the dura until the foramen spinosum was reached. Intradurally, the carotid and sylvian cisterns were opened. After the temporal lobe was retracted, the interpeduncular and ambient cisterns were opened and the P2 segment of the PCA was exposed. The MMA trunk was transsected just before the bifurcation of its anterior and posterior branches where it passes inside the dura and over the foramen spinosum. It was anastomosed end to side with the P2 segment of the PCA. The mean caliber of the MMA trunk before its bifurcation was 2.1 +/- 0.25 mm, and the mean caliber of the P2 was 2.2 +/- 0.2 mm. The mean length of the MMA used to perform the bypass was 32 +/- 4.1 mm, and the mean length of the MMA trunk was 39.5 +/- 4.4 mm. This bypass procedure is simpler to perform than an ECA-to-P2 revascularization using long grafts. The caliber and length of the MMA trunk are suitable to provide sufficient blood flow. Furthermore, the course of the bypass is straight.