RESUMO
There is an infrequent disposition of the first metacarpal artery which results in an anastomosis with the common palmar digital artery of the second space, forming an anastomotic system between the deep radial system and the superficial ulnar system. The radial system in turn, through the first dorsal interosseous artery, anastomoses with a collateral of the common palmar digital artery of the second space, ending as the ulnar palmar digital artery of the thumb and establishing a second anastomotic system. A third anastomosis is established in one case, between the common palmar digital artery of the fourth space and the fourth metacarpal artery. To this may be added the classic anastomosis between the superficial branch of the ulnar artery and the deep branch of the radial artery, i.e. the deep palmar arch.
Assuntos
Ossos Metacarpais , Polegar , Mãos , Ossos Metacarpais/cirurgia , Artéria RadialRESUMO
INTRODUCTION: Double innervation of the brachialis muscle has been previously reported in anatomical studies. This study aims to investigate the frequency and clinical significance of double innervation of brachialis by anatomical and electromyographic techniques. MATERIALS AND METHODS: (1) The existence, origin and pattern of distribution of a branch from the radial nerve to brachialis were dissected on 20 cadaveric arms. (2) Nerve conduction studies (NCS) of 100 patients were performed. The radial nerve was stimulated, registering muscle potentials (MP) in the brachialis muscle. Subsequently, another MP was obtained by Erb's stimulation, corresponding to the whole brachialis innervation. The relative percentage of innervation from the radial nerve was calculated. (3) Two patients with lesions of the lateral cord of the brachial plexus and preserved elbow flexion were submitted to NCS. RESULTS: Double innervation was found in 65 % of the anatomical preparations, following different patterns of distribution. In the NCS, 90% of the patients showed MP in the brachialis muscle after stimulating the radial nerve. The mean percentage of relative innervation was 11 %. Two patients with lesions of the lateral cord showed an important contribution from the radial nerve. CONCLUSIONS: Variations in the relative percentage of innervation from the radial nerve could be due to the different sizes and shapes of this branch. The functional significance of this branch can become crucial if the main innervation to the brachialis muscle fails. When planning surgical antero-external approach to the humerus, it should be kept in mind and preserved.
Assuntos
Braço/inervação , Braço/fisiologia , Músculo Esquelético/inervação , Músculo Esquelético/fisiologia , Nervo Radial/fisiologia , Idoso , Idoso de 80 Anos ou mais , Braço/anatomia & histologia , Plexo Braquial , Cadáver , Eletromiografia/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/anatomia & histologia , Condução Nervosa/fisiologia , Nervo Radial/anatomia & histologiaRESUMO
The present work deals with a study of the supraduodenal a. in 30 specimens. It was present in 28 cases: when absent it was substituted by the right gastric a. Its origin is discussed, the most frequent being the gastroduodenal a., with 2 cases in the pericholedochal plexus. Distribution to the distal two thirds of the upper portion of the duodenum was constant, extending to the supra- and retroduodenal portions of the common duct. Its anastomosis with the gastric right a. and the posterior superior pancreaticoduodenal a. was established in half the cases, being more frequent with the former.