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Background: This study focused on the anatomical characteristics and variations of intercostobrachial (ICBN) nerve and median nerve to investigate the possible use of ICBN in restoration of sensory damage of hand after traumatic median nerve injury and to evaluate the feasibility of ICBN neurotization to median nerve., Methods: Variations of ICBN were noted in 16 axillary region dissections of eight cadavers. Measurements for ICBN's suitability in terms of neurotization to brachial plexus were done with millimetric devices. The distance of ICBN to the distal end of the lateral (LCMN) and medial (MCMN) contributions of the median nerve and the diameters of ICBN, LCMN, and MCMN were measured., Results: Fifteen axillary dissections exhibited ICBN, whereas it was absent on the left side of one of the cadavers. The mean diameter of ICBN at its origin was 2.0±0.7 mm and the mean diameter of ICBN at its coaptation point was 3.1±0.9 mm. The mean diameter of the LCMN was 3.9±2.0 mm, the mean diameter of MCMN was 3.5±0.9 mm. The length of ICBN was found to be adequate at both 45 and 90° of shoulder abduction to be extended to both LCMN and MCMN. The diameters of LCMN and MCMN were not significantly correlated with the diameter of ICBN both at origin and at coaptation point (LCMN: p=0.55-0.63 and MCMN: p=0.89-0.85). There is no significant difference between the diameter of LCMN and the diameter of ICBN at its coaptation point (p=0.168) and also between the diameter of MCMN and the diameter of ICBN at its coaptation point (p=0.232)., Conclusion: All ICBNs dissected showed adequate length to reach the lateral and medial contribution of the median nerve directly. The ICBN could be a feasible candidate since its diameter was close to LCMN and MCMN according to the descriptive and inferential statistics.

Objective: Few donors are available for restoration of sensibility in patients with complete brachial plexus injuries. The objective of our study was to evaluate the anatomical feasibility of using the intercostobrachial nerve (ICBN) as an axon donor to the lateral cord contribution to the median nerve (LCMN)., Methods: Thirty cadavers were dissected. Data of the ICBN and the LCMN were collected, including diameters, branches and distances., Results: The diameters of the ICBN and the LCMN at their point of coaptation were 2.7mm and 3.7mm, respectively. The ICBN originated as a single trunk in 93.3% of the specimens and bifurcated in 73.3%. The distance between the ICBN origin and its point of coaptation to the LCMN was 54mm. All ICBNs had enough extension to reach the LCMN., Conclusion: Transfer of the ICBN to the LCMN is anatomically feasible and may be useful for restoring sensation in patients with complete brachial plexus injuries.

Purpose: The aim of this study was to precisely determine the course of the intercostobrachial nerve (ICBN) in the axillary region and as it is related to bony landmarks, and all of this might be of use for transaxillary breast augmentation., Methods: Thirty hemithoraxes of 15 fresh cadavers of Korean adults were dissected. After removal of the skin, the ICBN from its origin was identified. The point of emergence (EP) and the branching point (BP) were marked on translucent paper., Results: The ICBN appeared at the second intercostal space approximately (mean ± SD; 33.4 ± 12.7) mm lateral to the midclavicular line and 9.8 ± 6.4 mm medial to the lateral border of the pectoralis minor (P minor) muscle. The mean (SD) distance from the lower border of the second rib to the EP was 5.2 ± 2.0 mm. The mean ± SD distance from the upper border of the third rib to the EP was 12.7 ± 3.3 mm. It traveled inferolaterally (mean ± SD) 15.1 ± 10.4 degrees from the horizontal plane) 39.4 ± 19.2 mm to reach to the BP. The BP was located at the second intercostal space approximately (mean ± SD) 59.4 ± 21.2 mm lateral to the midclavicular line and 28.5 ± 18.2 mm lateral to the lateral border of the P minor muscle. The mean ± SD distance from the lower border of the second rib to the BP was 11.3 ± 5.4 mm. The mean ± SD distance from the upper border of the third rib to the BP was 6.3 ± 7.1 mm. At the BP, the ICBN gave off a medial brachial cutaneous nerve, and this coursed superolaterally [mean (mean ± SD, 50.7 ± 15.1 degrees from the horizontal plane) toward the medial surface of the upper arm. The mean ± SD depth of the ICBN from the superficial surface of the pectoralis major and P minor was 22.7 ± 5.7 mm and 15.0 ± 5.2 mm, respectively., Conclusion: When performing mammary augmentation, care should be taken not to dissect the undersurface of the P minor at the second intercostal space to avoid injury to the ICBN.

The purpose of this study was to investigate the anatomical basis of intercostal nerve transfer to the suprascapular nerve and provide a case report. Thoracic walls of 30 embalmed human cadavers were used to investigate the anatomical feasibility for neurotization of the suprascapular nerve with intercostal nerves in brachial plexus root avulsions. We found that the 3rd and 4th intercostal nerves could be transferred to the suprascapular nerve without a nerve graft. Based on the anatomical study, the 3rd and 4th intercostal nerves were transferred to the suprascapular nerve via the deltopectoral approach in a 42-year-old man who had had C5-7 root avulsions and partial injury of C8, T1 of the right brachial plexus. Thirty-two months postoperatively, the patient gained 30° of shoulder abduction and 45° of external rotation. This procedure provided us with a reliable and convenient method for shoulder function reconstruction after brachial plexus root avulsion accompanied with spinal accessory nerve injury. It can also be used when the accessory nerve is intact but needs to be preserved for better shoulder stability or possible future trapezius transfer.

Objective: To investigate the feasibility of the 3rd-6th intercostal nerve transfer to the suprascapular nerve for reconstruction of shoulder abduction., Methods: Fifteen thoracic walls (30 sides) were collected from cadavers. The 3rd-6th intercostal nerve length which can be dissected between the midaxillary line and midclavicular the transfer distance between the midaxillary line and midpoint of the clavicular bone (prepared point for neurotization) measured., Results: In 30 sides of specimens, the 3rd and 4th intercostal nerves could be obtained between the midaxillary and midclavicular line, the available length of which was significantly greater than the transfer distance (P < 0.01). Six 5th intercostal nerve and 16 sides of 6th intercostal nerve were covered by the costal cartilage before reaching the midclavicular line. The available length of the 5th intercostal nerve was similar to the transfer distance (P > 0.01), while the available the 6th intercostal nerve was significantly less than transfer distance (P < 0.01). The suprascapular nerve could be dissociated turned to the clavicular bone of more than 2 cm. The whole length of the available 5th intercostal nerve length and length (2 cm) of suprascapular nerve was significantly greater than the transfer distance (P < 0.01), but for the 6th nerve, the whole length was still less than transfer distance (P < 0.01)., Conclusion: It could be an alternative method the 3rd, 4th, and 5th intercostal nerve transfer to the suprascapular nerve for reconstruction of shoulder abduction. And 6th intercostal nerve, longer dissociated length may be required for direct coaptation or using a graft for nerve repair.

Although the complex architecture of the brachial plexus (BP) has been described for decades, recent literature still aims to elucidate the variation in nerve root contributions to the BP. Understanding this variability in the nerve morphology of the BP may assist physicians and surgeons in the diagnosis and management of certain clinical conditions that involve the BP, either directly or indirectly due to its close association with neighbouring structures. In this article, we review the current anatomical knowledge of the BP, focusing especially on its T2 contribution, and discuss the causes and consequences of some relevant BP pathologies.

Purpose: To evaluate the feasibility of restoring the deltoid function in patients with C5 through C7 root avulsion injuries by transferring 2 intercostal nerves to the anterior branch of the axillary nerve through a posterior approach. The preliminary results of the clinical application of this procedure also are reported., Methods: The study was performed on 10 fresh cadavers. The lengths of the third, fourth, and fifth intercostal nerves from the costochondral junction to the midaxillary line were recorded. The distance from the pivot point at the midaxillary line to the anterior branch of the axillary nerve was recorded as the tunnel length. All histomorphometric measurements of the axon number were recorded. Based on the anatomic study, the fourth and fifth intercostal nerves were transferred directly to the anterior branch of the axillary nerve in 2 patients., Results: The average distances from the costochondral junction of the third, fourth, and fifth intercostal nerves to the pivot points were 12, 15, and 16 cm, respectively. The average tunnel distances of the third, fourth, and fifth intercostal nerves were 11, 13, and 15 cm, respectively. The average numbers of myelinated nerve fibers of the third, fourth, and fifth intercostal nerves were 742, 830, and 1,353, respectively. At the 2-year follow-up evaluation the preliminary clinical results showed that the deltoid recovered against resistance (M4). The range of motion for shoulder abduction and external rotation were both 95 degrees in the first case and 105 degrees and 95 degrees , respectively, in the second case. Useful functional recovery was achieved and classified as a good result in both patients., Conclusions: This anatomic study with 2 case reports supports the idea that transfer of 2 intercostal nerves to the anterior branch of the axillary nerve through the posterior approach could be an alternative method for reconstruction of the deltoid muscle in C5 through C7 root avulsion injuries., Type of Study/level of Evidence: Therapeutic IV.

Objective: Recent advancements in neurotization and nerve grafting procedures have led to an increasing need for knowledge of the detailed anatomy of communicating branches between peripheral nerves. Although the surgical anatomy of the axilla has been well described, little is known regarding the degree or frequency of potential contributions to or communications with the brachial plexus. The aim of our study, therefore, was to explore extrathoracic, as well as potential intrathoracic, contributions to the brachial plexus from T2., Methods: The anatomy of the ventral primary ramus of T2 and the second intercostal nerve, including its lateral cutaneous contribution as the intercostobrachial nerve, was examined in 75 adult human cadavers (150 axillae), with particular emphasis on the communications with the brachial plexus., Results: Extrathoracically, communications were observed to occur in 86% of specimens. These contributions arose variably from either the intercostobrachial nerve or one of its branches and communicated with the medial cord (35.6%), medial antebrachial cutaneous nerve (25.5%), or posterior antebrachial cutaneous nerve (24%). Whereas the majority of specimens (68.2%) were observed to have only one extrathoracic communication, 31.7% of specimens exhibited two. Intrathoracically, communications were observed to occur in 17.3% of specimens. These communications always arose from the ventral primary ramus of T2. When combining and comparing data within individual specimens, it was observed that those axillae without an extrathoracic contribution from the intercostobrachial nerve always contained an intrathoracic communication., Conclusion: Based on our findings, we conclude that 100% of specimens contained a communication branch between T2 and the brachial plexus. Considering the possible implications of this data, with regards to sensory innervation of the arm and axilla, further studies in this area of research could prove extremely beneficial.

Recent reports emphasize the importance of preserving the intercostobrachial nerve (ICBN) during surgical procedures (i.e., mastectomy, axillary clearance). However, a limited number of scientific reports explore the surgical anatomy of this nerve. We dissected 100 adult human formalin-fixed cadavers (200 axillae). In all the cadavers the ICBN was present with variant contributions from intercostal nerves T1, T2, T3, and T4. The arrangements of the ICBN were typed as I through VIII. The components of Type I (45% or 90 of our specimens) included a branch to the posterior antebrachial cutaneous nerve, a branch to the anterior and lateral parts of the axilla, a branch to the medial side of the arm, and a branch to the medial antebrachial cutaneous nerve. Type II (25%) describes the ICBN arising from T2 and giving off a branch to the brachial plexus. In Type III (10%), lateral cutaneous branches of T2 and T3 fuse as a common trunk and then split immediately after exiting the intercostal space to form an ICBN. In type IV (5%), T2 and T3 join distally to form an ICBN that ends as its terminal branches. Type V (5%): T3 joins T2 from the same intercostal space proximally, with Type VI (3%) showing a very proximal branching of the sensory terminal nerves. Type VII (5%) displayed a contribution from T3 and a branch to the brachial plexus with multiple terminating branches. A contribution from T3 and T4 and a branch to the brachial plexus with multiple branches of termination comprised Type VIII (2%).

The motor and sensory fiber arrangements in the proximal region of the spinal nerves are important for understanding the relationship of the peripheral nerves to neuron distribution. On the other hand, the fiber arrangements are also important for the treatment of peripheral nerve grafting. We studied the fiber arrangements of two divisions (ventral and dorsal) in the proximal region of the brachial plexus and the fiber arrangements of the lateral cutaneous rami in Th7 and Th8 intercostal nerves in adult rats with a method using the fluorescent pigments DiI and DiO. Results showed that fiber arrangements belonging to the two divisions have a specific separate distribution in the distal region. However, this specific separate distribution form was absent in the proximal region of the spinal nerves in the plexus. Fiber arrangements of the lateral cutaneous ramus in the anterior branches of the thoracic nerves (intercostal nerves) were also observed in comparison with those in the brachial plexus by the same method. In the intercostal nerves, fibers of the lateral cutaneous ramus were distributed in the dorsal portion from distal to proximal. These results suggest that there are two types of fiber arrangement in the proximal regions of the spinal nerves: a ventrodorsal distributional type, comprising intercostal nerves and the dorsal branches of the spinal nerves; and a mixed type, comprising the anterior branches of the cervical and brachial (and perhaps lumbar) plexuses. On the other hand, fibers of the lateral cutaneous rami in the intercostal nerves were distributed on the dorsal part of the nerves. These results of fiber arrangement analysis for the intercostal nerves may offer an opportunity to improve the effect of treatments using peripheral nerve grafting and suturing in the brachial and lumbar plexus with intercostal nerves.

Background: In the past decade surgeons have become increasingly aware of the morbidity caused by the division of the intercostobrachial nerve (ICBN) during axillary dissection. To prevent this problem and also to explain its variable occurrence, a detailed knowledge of the anatomy of the nerve is required., Methods: Twenty-eight axillary dissections were performed demonstrating the anatomy of the ICBN., Results: In all dissections the nerve originated from the second intercostal space, with contributions from the first and third intercostal nerve each on one occasion. The posterior axillary branch was constant but may branch early, simulating a second nerve. The ICBN had a variable relationship to the lateral thoracic vein: anterior, posterior or wrapping around it. In 36% there was a connection to the medial cord of the brachial plexus in the axilla. In the upper arm the nerve lies in the subcutaneous fat; in the majority it supplied at least the proximal half of the arm, and in one-third it reached the level of the elbow joint. In 18% there was a connection to the medial cutaneous nerve of the arm., Conclusion: The ICBN and its main branch (the posterior axillary nerve) were constant in all dissections. But its origin, size, connection to the brachial plexus and medial cutaneous nerve of the arm were variable, as was its ultimate destination in the arm.

Unlabelled: The aim of the study was a morphometric evaluation of the intercostal nerves at different levels along their course in order to determine their adequacy in neurotizing the recipient nerves. The intercostal nerves were harvested from 5 cadavers. A biopsy of the nerve was obtained at 2 levels for each nerve in the parasternal region and at the level of the mid-axillary line. The musculocutaneous nerve was isolated at its origin from the lateral cord. Each harvested specimen was embedded in paraffin and sections were made using a microtome. These sections were then stained histochemically using HPS (Hematein, Phloxine, Safran). Real-time digitalisation of the video image under the microscope was performed. The sum of the different fascicular zones is the effective sensorimotor surface of the nerve at the level being studied., Results: Direct suture of the upper three intercostal nerves to the musculocutaneous nerve is always possible upto the axillary fossa. The sixth intercostal nerve can be delivered upto this level in only 50% of cases without dissection of the musculocutaneous nerve upto its entry into the coracobrachialis. The musculocutaneous nerve presents a mean surface area of 2.64 mm2 while the nerve to the biceps has a mean surface area of 0.34 mm2 i.e. a ration of 1/8. The mean surface area of the intercostal nerves at the parasternal level is 0.23 mm2 while that at the axillary level is 0.34 mm2. Thus a loss of 33% in surface area occurs between the axillary and the parasternal levels. Our study confirms the insufficiency between the surface area of the intercostal nerves and the different nerve trunks to be neurotized. The relationship between the surface area of the musculocutaneous nerve and the three intercostal nerves is 26.72% with a minimum of 17.2%. If a fourth intercostal nerve is added, this ratio nerves appears to be a superior technique. We were able to deliver the sixth intercostal nerve for a direct suture to the musculocutaneous nerve in only half the cases.

A rostrocaudal somatotopic organization in the rat lumbar dorsal root ganglia (DRGs) during development has been demonstrated. The present study shows that such a rostrocaudal somatotopic organization also exists in the brachial DRGs of neonatal rats. WGA-HRP or WGA-HRP/HRP injections into the forepaw of neonatal rats gave rise to completely and partially labeled DRGs. Partial labeling always concerned the caudal or rostral halves of the rostral-most or caudal-most labeled DRGs, respectively. Labeling of forelimb nerves (cutaneous branch of the musculocutaneous nerve, median and ulnar nerve) in neonatal rats also resulted in whole labeled DRGs and labeled rostral or caudal halves of DRGs. Accordingly, just as was found for the hind limb nerves, the position of the somata of the sensory neurons of forelimb nerves can be restricted to the rostral or caudal half of a DRG. Moreover, it was observed that the rostrocaudal organization in the brachial DRGs is maintained in the spinal nerves. Application of tracer to the cut end of intercostal nerves in neonatal rats produced labeling of one whole thoracic DRG. It is therefore possible that the rostrocaudal organization in the brachial and lumbar DRGs is a consequence of the formation of the plexuses. In one instance a subdivision in the labeling pattern of a midthoracic DRG was noticed after a WGA-HRP injection into the thoracic wall of a neonatal rat. The whole thoracic DRG was labeled except the dorsorostral corner. This indicates that during development, some kind of somatotopic organization may exist also in the thoracic DRG.