Architectural properties of the neuromuscular compartments in selected forearm skeletal muscles.

The purposes f this study were to (i) explore the possibility of splitting the selected forearm muscles into separate compartments in human subjects; (ii) quantify the architectural properties of each neuromuscular compartment; and (iii) discuss the implication of these properties in split tendon transfer procedures. Twenty upper limbs from 10 fresh human cadavers were used in this study. Ten limbs of five cadavers were used for intramuscular nerve study by modified Sihler's staining technique, which confirmed the neuromuscular compartments. The other 10 limbs were included for architectural analysis of neuromuscular compartments. The architectural features of the compartments including muscle weight, muscle length, fiber length, pennation angle, and sarcomere length were determined. Physiological cross-sectional area and fiber length/muscle length ratio were calculated. Five of the selected forearm muscles were ideal candidates for splitting, including flexor carpi ulnaris, flexor carpi radials, extensor carpi radialis brevis, extensor carpi ulnaris and pronator teres. The humeral head of pronator teres contained the longest fiber length (6.23 ± 0.31 cm), and the radial compartment of extensor carpi ulnaris contained the shortest (2.90 ± 0.28 cm). The ulnar compartment of flexor carpi ulnaris had the largest physiological cross-sectional area (5.17 ± 0.59 cm(2)), and the ulnar head of pronator teres had the smallest (0.67 ± 0.06 cm(2)). Fiber length/muscle length ratios of the neuromuscular compartments were relatively low (average 0.27 ± 0.09, range 0.18-0.39) except for the ulnar head of pronator teres, which had the highest one (0.72 ± 0.05). Using modified Sihler's technique, this research demonstrated that each compartment of these selected forearm muscles has its own neurovascular supply after being split along its central tendon. Data of the architectural properties of each neuromuscular compartment provide insight into the 'design' of their functional capability. In addition to improving our understanding of muscle anatomy and function, elucidation of forearm neuromuscular compartments architecture may ultimately provide information useful for selection of muscle subdivisions used in tendon transfer.

Profiling of innervations of mimetic muscles in fresh human cadavers using a modified Sihler's technique.

The nerve map of the human face, although important in guiding facial surgery, has not been well defined. In this study we applied a modified Sihler's technique to profile intramuscular innervation of human mimetic muscles. Six fresh cadaveric heads were used. The intramuscular distribution of the facial nerve in human mimetic muscles was visualized using a modified Sihler's technique. Modified Sihler's staining revealed a three-dimensional picture of the clearly purple-black intramuscular facial and sensory nerves. The nerve branching patterns of both facial halves were asymmetrical. None of the fine nerve branches crossed over the midline. The facial nerve branches divided into secondary rami and formed a mesh-like plexus before entering the target muscles at a right angle. The modified Sihler's technique can profile intramuscular innervation of human mimetic muscles. Our nerve map of the face offers valuable guidance for facial reanimation surgery, facial cosmetic surgery, and parotid surgery.

Intramuscular innervations of muscle flaps that are commonly used in clinical settings.

PURPOSE: Abductor hallucis, latissimus dorsi, gracilis, rectus abdominis, sartorius and pectoralis minor are muscle flaps that are commonly used in clinic, but their intramuscular innervation has seldom been systematically investigated. METHODS: Five Chinese fresh human cadavers were included in the study and abductor hallucis, latissimus dorsi, gracilis, rectus abdominis, sartorius and pectoralis muscles were dissected. After gross anatomy measurement, the specimens were then stained by Sihler's staining technique. Intramuscular innervation was observed and the number as well as distribution was recorded. RESULTS: Intramuscular nerves were clearly visualized by Sihler's staining technique. Based on the shape and muscle-tendon morphology, Lim et al. in Muscle Nerve 29:523-530, 2004 grouped the muscles into trapezoidal-shaped (type I), spindle-shaped (type II), and combination-shaped (type III). According to Lim's study the abductor hallucis was a type IIb muscle and was divided into two compartments by the distal tendon. Latissimus dorsi was a type I muscle, divided into 3-4 compartments by intramuscular nerve branches. Gracilis was a type IIa muscle and the distal part was divided into two compartments by intramuscular nerve branches. Rectus abdominis was a type III muscle and the four bellies comprised four compartments, each of which could be designated as a subunit. Sartorius was a type II muscle and it could be divided into 2-3 compartments along the long axis. Pectoralis minor was a type I muscle that was divided into two compartments by extramuscular terminal nerves. CONCLUSIONS: The six muscles are divided into several compartments by the tendon or nerve branches, and all of them make good donor tissue for muscle compartment transfer in reconstructive surgery.

Neurovascular details about forearm muscles: applications in their clinical use in functional muscular transfer.

PURPOSE: The concept of muscle subunits has been introduced for limb reconstruction and functional conservation of donor site, yet it requires thorough understanding of neurovascular anatomy of muscles. The present study provides neurovascular details of forearm skeletal muscles. METHODS: Twenty-eight forearms were dissected totally, ten for observing extramuscular nerve distribution, ten for observing intramuscular nerve distribution by modified Sihler's technique, and the other eight for observing intramuscular artery distribution by aqueous barium sulfate infusion. The forearm muscles were classified into three different types according to Lym's classification. Numbers of extramuscular and intramuscular nerves were counted and compared between the types. Intramuscular vascular distribution was also classified into three different types according to Mathes' method. Intramuscular vascular distribution was compared with nerve distribution as well. RESULTS: There were also some variations in the composition of muscular branches. Numbers of intramuscular nerve branches were significantly higher in muscle types IIa and III. Morphology and intramuscular neurovascular distribution of type II muscles are easy to split into two independent parts for functional muscular flap transfer according to morphology and intramuscular neurovascular distribution. CONCLUSIONS: The present study elucidated that flexor carpi ulnaris and radialis, extensor carpi ulnaris, and carpi radialis brevis were suitable for functional muscular transfer from several different insights, but the roles of pronator teres and supinator remained to be controversial. This study might be very helpful to plastic surgeons and anatomists.

Blood pH in coronary artery microthrombosis of rats.

OBJECTIVE: To study the mechanism and significance of pH change in the coronary artery microthrombosis of rats. METHODS: After the sodium laurate-induced model of coronary artery microthrombosis of rats was constructed, the vascular endothelial cells were separated and then cultured in the mediums with different pH values for 24 h. Enzyme linked immunosorbent assay was used to detect the content of von Willebrand factor (vWF) in the medium; while the real-time PCR and western blot assay were used to detect the expression of fibrinogen-like protein 2 (FGL2) at the mRNA and protein level. The comprehensive evaluation was performed to discuss the effect of pH change on the coronary artery microthrombosis of rats. RESULTS: The expression level of vWF detected by enzyme linked immunosorbent assay was 336.67 ± 24.95, 311.33 ± 14.98, 359.67 ± 39.63, 354.67 ± 49.01 and 332.00 ± 33.42 (pg/mL) respectively; while the expression of vWF in the model group was 570.00 ± 57.94, 524.67 ± 57.94, 437.00 ± 95.38, 415.33 ± 44.38 and 444.67 ± 74.31 respectively. Being cultured under the different pH values, the relative expression level of FGL2 mRNA in the model group was 7.93 ± 0.93, 6.70 ± 0.70, 5.03 ± 0.32, 5.13 ± 0.40 and 5.57 ± 0.83 respectively. CONCLUSIONS: The coronary artery microthrombosis of rats can cause the high expression and secretion of vWF. Meanwhile, FGL2 is also up-regulated in the thrombosis and such up-regulation is more significant in the condition with low pH, which indicates that the low pH condition may be one of factors that contribute to the cardiovascular diseases.

[The reconstruction of erectile function with rabbit segmental gracilis musculocutaneous flap].

OBJECTIVE: To design an animal model for the reconstruction of penile erectile function with segmental gracilis musculocutaneous flap. METHODS: The rabbit gracilis muscle was split longitudinally into two approximately equal halves completely according to the principles of muscle compartmentalization. An animal model was designed for the reconstruction of erectile function with segmental musculocutaneous flap based on the anterior gracilis muscle bundle, with a silicone stick implanted as a supporter. A multi-channel physiological signal acquisition and processing system were used to stimulate the reconstructed penis and its CMAP was measured synchronously. RESULTS: When its nerve was electric stimulated, the muscle bundle contracted, which made the reconstructed penis moving accordingly. It satisfactorily simulated the way of a normal penis's erection. CONCLUSIONS: The reconstructed penis with rabbit segmental gracilis musculocutaneous flap according to the principles of muscle compartmentalization has achieved the erectile function satisfactorily. It has met the requirements of both improving reconstructive penis's appearance and retaining muscle' s contractive function.

Two methods can simultaneously display both intramuscular nerves and blood vessels.

BACKGROUND: The arrangement and relationship of intramuscular nerves and blood vessels are critical to clinical physicians, but the majority of previous studies could not reflect them precisely. METHODS: In method 1, after rabbits were perfused with barium sulfate liquid silica gel, the specimen muscle was isolated and subjected to Sihler staining. The specimen muscles then underwent optical photography and molybdenum target radiography. The obtained photograph and the radiograph were then overlapped together to draw a map of intramuscular nerves and blood vessels. In method 2, after rabbits and child cadavers were perfused with semitransparent red liquid silica gel, the specimen muscle was isolated and subjected to Sihler staining. Finally, the specimen muscles were placed on an x-ray film viewer for photography. RESULTS: Both methods had ideal outcomes. Through digital subtraction angiography, a distribution map of intramuscular nerves and blood vessels could be obtained in method 1, whereas in the photographs taken through method 2, the intramuscular nerves were counterstained with dark blue and the intramuscular blood vessels were stained red, which was more precise and direct. In method 2, specimens could be made into stereoscopic models. CONCLUSIONS: These two methods that can simultaneously display intramuscular nerves and blood vessels have been significantly improved and lead to a good result. They also have their own advantages. When a muscle studied is small or flat, method 2 is recommended because of its conciseness and convenience. If the muscle is large, method 1 is applicable.

[MAFbx and MuRF1 mRNA expression and its relationship with muscular contractility following free muscle transfer].

OBJECTIVE: To study muscle atrophy F-box (MAFbx) and muscle ring finger 1 (MuRF1) mRNA expression and its relationship with muscular contraction following free muscle transfer. METHODS: The gracilis muscle was orthotopic transferred in adult rat to establish the animal model. The muscle at the unoperated side was used as control. The expression of MAFbx and MuRF1 mRNA, the muscle contraction and muscle function were measured by real-time PCR and multiple function physiological device. The relationship among the expression of MAFbx and MuRF1 mRNA, the muscle contraction and muscle function was analyzed. RESULTS: After muscle free transfer, muscle wet weight reservation, the maximum contraction and tetanus strength reduce first and increased later, but still lower than those at control side. The expression of MAFbx and MuRF1 mRNA reached peak level 3 - 4 weeks after muscle transfer which was 7.1 and 4.1 times as that at control side. It decreased later, but still higher than that at control side, showing a significant difference between them (P< 0. 05). CONCLUSIONS: Persistent over-expression of MAFbx and MuRF1 mRNA after muscle transfer has a close relationship with muscle atrophy and muscle dysfunction. MAFbx and MuRF1 can be used as markers for early muscle atrophy, and also as potential target for drug treatment of muscle atrophy.

[Anatomy of buccal and marginal mandibular branches of facial nerve and its clinical significance].

OBJECTIVE: To study the course and distribution of buccal and marginal mandibular branches of facial nerve, and its relevance to the treatment of facial paralysis and the protection of facial nerve during surgery. METHODS: 12 cadaver heads were dissected (24 specimens). The course of the buccal and marginal mandibular branch and the interconnections between them were observed. The relationship of buccal branch to parotid duct, marginal mandibular branch to the inferior border of mandible were studied. With modified Sihler's staining technique, the distribution of facial nerve branches in innervated mimetic muscles was displayed. These anatomic relationships mentioned above were further confirmed during the operation of 40 patients with facial paralysis. RESULTS: Parotid duct had a constant surface landmark. Buccal branch mainly consisted of 2-3 ramifications in 87.5% of the specimens, while marginal mandibular branch was double or single in 95.9% of the specimens. The buccal branch coursed within the distance between 10.7 mm above and 9.3 mm below the parotid duct, and innervated mimetic muscles of midface. The marginal mandibular branch coursed within the distance between 13.4 mm above and 4.8 mm below the lower border of mandible, crossed superiorly the facial artery and innervated mimetic muscles of lower lip. CONCLUSIONS: There is a close relationship of buccal branch to parotid duct and marginal mandibular branch to facial artery and lower border of mandible. With modified Sihler's staining technique, the original 3-dimensional picture of the intramuscular nerve distribution in human mimetic muscles.