The zonal pattern of arterial supply to the brachial plexus and its clinical significance.

PURPOSE: To provide the anatomical basis of blood supply of brachial plexus for the clinical microsurgical treatment of brachial plexus injury. METHODS: Thirteen adult anticorrosive cadaveric specimens (8 males, 5 females) were dissected in this study. 3 fresh cases (2 males, 1 female) were used to observe the zonal pattern of arteries supplying brachial plexus, and 10 cases (6 males, 4 females) were used to observe the source and distribution of the brachial plexus arteries under microscope. RESULTS: The brachial plexus is supplied by branches of the subclavian-axillary axis (SAA), and these branches anastomose each other. According to distribution feature, blood supply of the brachial plexus could be divided into three zones. The first zone was from the nerve roots of intervertebral foramina to its proximal trunks, which was supplied by the vertebral artery and the deep cervical artery. The second zone was from the distal nerve trunks of the brachial plexus, encompassing the divisions to its proximal cords, which was supplied by direct branches of the subclavian artery or by branches originating from the dorsal scapular artery. The third zone was from the distal portion of the cords to terminal branches of the brachial plexus, which was supplied by direct branches of the axillary artery. CONCLUSIONS: The zonal pattern of arterial supply to the brachial plexus is a systematic and comprehensive modality to improve anatomical basis for the clinical microsurgical treatment for brachial plexus injury.

Microanatomy of the brachial plexus roots and its clinical significance.

PURPOSE: To provide the anatomical basis of brachial plexus roots for the diagnosis and treatment of brachial plexus root avulsion injury. METHODS: The morphological features of brachial plexus roots were observed and measured on 15 cervicothoracic spine of adult cadavers. The relationship of brachial plexus nerve roots and the surrounding tissues also were observed, as well as the blood supply of anterior and posterior roots of the brachial plexus. RESULTS: Origination of the nerve roots in the dorsal-ventral direction from the midline was fine-tuned at each level along the spinal cord. The minimum distance of the origin of the nerve root to midline was 2.2 mm at C 5, while the maximum was 3.1 mm at T 1. Inversely, the distance between the origin of the posterior root and the midline of the spinal cord gradually decreased, the maximum being 4.2 mm at C 5 and minimum 2.7 mm at T 1. Meanwhile, there was complicated fibrous connection among posterior roots of the brachial plexus. The C 5-6 nerve roots interlaced with tendons of the scalenus anterior and scalenus medius and fused with the transverse-radicular ligaments in the intervertebral foramina. However, these ligaments were not seen in C 7-8, and T 1. The blood supply of the anterior and posterior roots of the brachial plexus was from the segmental branches of the vertebral artery, deep cervical artery and ascending cervical artery, with a mean outer diameter of 0.61 mm. CONCLUSIONS: The systematic and comprehensive anatomic data of the brachial plexus roots provides the anatomical basis to diagnose and treat the brachial plexus root avulsion injury.

Prospective Study of Arterial Stiffness and Subsequent Cognitive Decline Among Community-Dwelling Older Japanese.

BACKGROUND: Brachial-ankle pulse wave velocity (baPWV) is inversely associated with cognitive function. However, it is not known whether baPWV predicts cognitive decline (CD) in later life. We examined whether or not baPWV is an independent risk marker of subsequent CD in a population of older Japanese. METHODS: Among 982 adults aged 65 years or older who participated in a baseline survey, 526 cognitively intact adults (Mini-Mental State Examination [MMSE] score ≥24; mean [SD] age, 71.7 [5.6] years; women, 57.8%) were followed for a period of up to 5 years. Pulse wave velocity was determined using an automated waveform analyser. Cognition was assessed by the MMSE, and CD was defined as a decrease of two points or more on the MMSE. RESULTS: During an average follow-up of 3.4 years, 85 participants (16.2%) developed CD. After controlling for important confounders, the odds ratios for CD in the highest and middle tertiles of baPWV, as compared with the lowest tertile, were 2.95 (95% confidence interval, 1.29-6.74) and 2.39 (95% confidence interval, 1.11-5.15), respectively. CONCLUSIONS: High baPWV was an independent predictor of CD in a general population of older adults and may be useful in the clinical evaluation of elders.

Plexiform nerve sheath tumor or vascular malformation--role of advanced MR neurography and diffusion tensor imaging.

The authors report a vascular malformation mimicking a plexiform peripheral nerve sheath tumor. Three Tesla magnetic resonance neurography with high-resolution anatomic and advanced functional diffusion tensor imaging was helpful in evaluating full extent of the lesion and characterizing its internal architecture.

Novel findings of the anatomy and variations of the axillary vein and its tributaries.

The anatomy and variations of the axillary vein has significant implications in various invasive procedures such as venous access, axillary block, arteriovenous fistula creation, axillary node dissection, breast augmentation, and other surgical procedures involving the axilla. To clarify the anatomy of the axillary vein and its tributaries, 40 cadaveric upper extremities were examined after dissection and were classified into several types according to the courses and terminations of brachial veins. The brachial veins ended separately (Type A; 72.5%) or made a common brachial vein (Type B; 27.5%) to enter the basilic vein or the axillary vein. The basilic vein was absent in 5.0% of the specimens. Duplication of the axillary vein was observed in 17.5% of the specimens and the lateral venous channel running along the lateral wall of the axilla was observed in 40.0% of the specimens. The most common drainage vein of the deep brachial vein was the lateral brachial vein (67.5%). The anterior circumflex humeral vein also emptied into the lateral brachial vein in 67.5% of the specimens. The posterior circumflex humeral vein crossed posterior side of the brachial plexus to join either the axillary vein (45.0%) or subscapular vein (42.5%). Perforation of the lateral root of median nerve by a lateral brachial vein, a common brachial vein, or a venous channel was observed in 15.0% of the specimens. Other venous variations accompanying the variations of the axillary artery or the brachial artery are described herein. The clinical importance of these findings is described in the discussion.

Sonoanatomy of the vasculature at the supraclavicular and interscalene regions relevant for brachial plexus block.

BACKGROUND: Our aim in this observational study was to utilize ultrasound, as well as anatomic dissection, to document the frequency with which branches of the subclavian vessels are found in close association with the brachial plexus at the locations of supraclavicular and interscalene brachial plexus block. METHODS: Ultrasound was utilized to document the presence of branches of the subclavian vein and artery, adjacent to the brachial plexus in the supraclavicular and in the interscalene region in 50 patients undergoing shoulder surgery. The position, depth, and dimensions of the vessels were described, and the origin determined when possible. In addition, the posterior triangle of the neck on both sides of three non-preserved cadavers was dissected to evaluate the vascular anatomy and correlate the ultrasound findings. RESULTS: Ultrasound scanning revealed an arterial branch adjacent to, or passing directly through, the brachial plexus in the supraclavicular region in 43/50 (86%) patients. Within the interscalene region, an artery was identified coursing in a lateral direction in 45/50 (90%) of cases, while a corresponding small vein, coursing medial to lateral in this area, was noted in 23/50 (46%) of cases. CONCLUSIONS: Small branch vessels from the subclavian artery and vein were frequently evident, on ultrasound imaging, in close association with the nerve elements of the brachial plexus in the supraclavicular and interscalene regions. Appreciation of the presence of these vessels and their likely origin and course will aid the anesthesiologist in planning a safe nerve block.

Sonographic assessment of arterial frequency and distribution within the brachial plexus: a comparison with the cadaveric record.

We investigated the number and distribution of arteries within the brachial plexus territory using a portable ultrasound device, and compared these findings with known cadaveric data. We recruited 200 volunteers and carried out 400 brachial plexus examinations in a prospective observational study design. We identified arteries within the brachial plexus in more than 90% of subjects. Most of these were located in the upper and middle zones of the plexus and therefore lie within the possible path of a block needle. These findings correlate well with previous cadaveric studies, suggesting that arteries within the brachial plexus territory can be reliably identified with a portable ultrasound device. The presence of these vessels may impact upon the safety and efficacy of brachial plexus blockade. Routine pre-procedural sonographic assessment may offer improved safety and efficacy. You can respond to this article at http://www.anaesthesiacorrespondence.com.

Demonstration of three injection methods for the analysis of extrinsic and intrinsic blood supply of the peripheral nerve.

BACKGROUND: The use of free vascularized nerve grafts requires an intimate and accurate knowledge of the blood supply of peripheral nerve. This study was designed to compare the advantages and disadvantages of three methods employed to reveal the blood supply of the peripheral nerve, and to provide morphological basis for vascularized nerve grafts. METHODS: The blood supply of brachial plexus and its main branches (ulnar, median, radial, musculocutaneous and axillary nerve) were observed using three vascular injection techniques: three specimens were injected with red latex through the thoracic aorta; two side specimens were injected with a Chinese ink solution, through the subclavian artery, for diaphanization and histology; one fresh cadaver was injected with the gelatin-lead oxide mixture through the femoral artery for radiography. RESULTS: The blood supply of the brachial plexus and its main branches was well examined using the three different vascular injection techniques. Perfusion with red latex exposed the extrinsic blood supply. Diaphanization and histology showed the intrinsic blood supply, while gelatin-lead oxide injection technique interactively displayed both the intrinsic and extrinsic blood supply to the peripheral nerve. CONCLUSION: The standard method for the study of the extrinsic blood supply to the peripheral nerve is the red latex perfusion; diaphanization and histology are very suitable to study the intrinsic blood supply of the peripheral nerve; while gelatin-lead oxide technique is the standard for visualization of the integral topography of the blood supply of the peripheral nerve.

Vascularized Brachial Plexus Allotransplantation-An Experimental Study in Brown Norway and Lewis Rats.

BACKGROUND: Brachial plexus injuries are devastating. Current reconstructive treatments achieve limited partial functionality. Vascularized brachial plexus allotransplantation could offer the best nerve graft fulfilling the like-with-like principle. In this experimental study, we assessed the feasibility of rat brachial plexus allotransplantation and analyzed its functional outcomes. METHODS: A free vascularized brachial plexus with a chimeric compound skin paddle flap based on the subclavian vessels was transplanted from a Brown Norway rat to a Lewis rat. This study has 2 parts. Protocol I aimed to develop the vascularized brachial plexus allotransplantation (VBP-allo) model. Four groups are compared: no reconstruction, VBP-allo with and without cyclosporine A immunosuppression, VBP autotransplantation (VBP-auto). Protocol II compared the recovery of the biceps muscle and forearm flexors when using all 5, 2 (C5 + C6) or 1 (isolated C6) spinal nerve as the donor nerves. The assessment was performed on week 16 and included muscle weight, functionality (grooming tests, muscle strength), electrophysiology and histomorphology of the targeted muscles. RESULTS: Protocol I showed, the VBP-allo with cyclosporine A immunosuppression was electrophysiologically and functionally comparable to VBP-auto and significantly superior to negative controls and absent immunosuppression. In protocol II, all groups had a comparable functional recovery in the biceps muscle. Only with 5 donor nerves did the forearm show good results compared with only 1 or 2 donor nerves. CONCLUSIONS: This study demonstrated a useful vascularized complete brachial plexus allotransplantation rodent model with successful forelimb function restoration under immunosuppression. Only the allotransplantation including all 5 roots as donor nerves achieved a forearm recovery.

The involvement of the peripheral nervous system in biopsy proven active giant cell arteritis.

BACKGROUND: Peripheral nervous system (PNS) affection is an uncommon, sometimes life-threatening manifestation of giant cell arteritis (GCA). OBJECTIVE: To describe characteristics of neurological abnormalities of the PNS in GCA patients. METHODS: Eighty consecutive cases of biopsy proven GCA were studied. RESULTS: Three patients presented with subacute sensorimotor deficits abnormalities in the distribution of the arm plexus. In all cases PNS affection was the leading clinical symptom in addition to a typical clinical syndrome of cranial arteriitis. In one case MRI demonstrated diffuse signal abnormalities surrounding the brachial nerve plexus. In another patient, who died from pulmonary embolism 10 weeks after beginning of therapy, autopsy demonstrated residual arteritis in an artery supplying the brachial nerve plexus. CONCLUSIONS: Involvement of the PNS is more uncommon than cerebral ischemia and neuroophthalmological complications in patients suffering from GCA. Severe PNS involvement has an affinity to the midcervical nerve roots and the brachial nerve plexus.

Impact of metabolic syndrome on brachial-ankle pulse wave velocity in Japanese.

The aim of this study was to determine the effect of metabolic syndrome on brachial-ankle pulse wave velocity (baPWV) by using the new guidelines for diagnosis of this syndrome in Japan. We examined 525 men and women without a history of cardiovascular disease or cancer, and an ankle-brachial index < 0.9. The baPWV was measured using a device (Form PWV/ABI) that simultaneously monitored bilateral brachial and ankle pressure wave forms. Metabolic syndrome was defined as a waist circumference > or = 85 (90) cm in men (women) and two or more of the following risk factors: hypertension, dyslipidemia, and glucose intolerance diagnosed by a 75 g oral glucose tolerance test. The baPWV showed a significant linear relationship with waist circumference, waist-to-hip ratio, body fat, systolic and diastolic blood pressure, triglycerides, fasting glucose, 2-h-postload glucose, fasting insulin, and glycosylated hemoglobin-A1c, after adjusting for sex and age. These factors were also strongly related to fasting insulin levels. When subjects were classified into six groups based on waist circumference and the number of risk factors for metabolic syndrome (0, 1, and > or =2), we found that more risk factors clearly increased the odds ratios for an elevated baPWV in those subjects in the highest quartile of the baPWV distribution in multivariate logistic models. An increase in odds ratio was observed despite a normal waist circumference and may well have been due to increased fasting insulin and blood pressure levels. An increase in the number of risk factors for metabolic syndrome was highly correlated with an increased baPWV, probably due to insulin resistance.

Ankle brachial index as a marker of atherosclerosis in Chinese patients with high cardiovascular risk.

To obtain reliable data on the epidemiology, co-morbidities and risk factor profile of peripheral arterial disease (PAD), we evaluated the clinical significance of the ankle brachial index (ABI) as an indicator of PAD in Chinese patients at high cardiovascular (CV) risk. ABI was measured in 5,646 Chinese patients at high CV risk, and PAD was defined as an ABI<0.9 in either leg. Multivariable logistic regression analyses were performed to identify factors associated with PAD. A total of 5,263 patients were analyzed, 52.9% male, mean age 67.3 years, mean body mass index (BMI) 24.2 kg/m2, mean systolic/diastolic blood pressure (SBP/DBP) 139/80.7 mmHg. The prevalence of PAD in the total group of patients was 25.4%, and the prevalence was higher in females than in males (27.1% vs. 23.9%; odds ratio [OR]: 1.64). Patients with PAD were older than those without PAD (72.3+/-9.9 years vs. 65.6+/-11.7 years; OR: 1.06), and more frequently had diabetes (43.3% vs. 31.3%; OR: 2.02), coronary heart disease (CHD) (27.0% vs. 18.8%; OR: 1.67), stroke (44.4% vs. 28.3%; OR: 1.78), lipid disorders (57.2% vs. 50.7%; OR: 1.3) and a smoking habit (42.7% vs. 38.6%; OR: 1.52). The ORs for the PAD group compared with the non-PAD group demonstrated that these conditions were inversely related to ABI. Statin, angiotensin-converting enzyme-inhibitors and antiplatelet agents were only used in 40.5%, 53.6% and 69.1% of PAD patients, respectively. The data demonstrated the high prevalence and low treatment of PAD in Chinese patients at high CV risk. A lower ABI was associated with generalized atherosclerosis. Based on these findings, ABI should be a routine measurement in high risk patients. Aggressive medication was required in these patients.

Arterial stiffness independently predicts cardiovascular events in an elderly community -- Longitudinal Investigation for the Longevity and Aging in Hokkaido County (LILAC) study.

We investigated the predictive value of arterial stiffness to assess cardiovascular risk in elderly community-dwelling people by means of a multivariate Cox model. In 298 people older than 75 years (120 men and 178 women, average age: 79.6 years), brachial-ankle pulse wave velocity (baPWV) was measured between the right arm and ankle in a supine position. The LILAC study started on July 25, 2000, consultation was repeated yearly, and the last follow-up ended on November 30, 2004. During this follow-up span of 1227 days, there were nine cardiovascular deaths, the cause of death being myocardial infarction for two men and three women or stroke for two men and two women. In Cox proportional hazard models, baPWV as well as age, Mini-Mental State Examination (MMSE), Hasegawa Dementia Scale Revised (HDSR) and the low-frequency/high-frequency (LF/HF) ratio showed a statistically significant association with the occurrence of cardiovascular death. A two-point increase in MMSE and HDSR score significantly protected against cardiovascular death, the relative risk (RR) being 0.776 (P = 0.0369) and 0.753 (P = 0.0029), respectively. The LF/HF ratio also was significant (P = 0.025), but the other indices of HRV were not. After adjustment for age and HDSR, a 200 cm/s increase in baPWV was associated with a 30.2% increase in risk (RR = 1.302, 95% CI: 1.110-1.525), and a 500 cm/s increase in baPWV with a 93.3% increase in risk (RR = 1.933, 95% CI: 1.300-2.874, P = 0.0011), whereas the LF/HF ratio was no longer associated with a statistically significant increase in cardiovascular mortality. In elderly community-dwelling people, arterial stiffness measured by means of baPWV predicted the occurrence of cardiovascular death beyond the prediction provided by age, gender, blood pressure and cognitive functions. baPWV should be added to the cardiovascular assessment in various clinical settings, including field medical surveys and preventive screening. The early detection of risk by chronomics allows the timely institution of prophylactic measures, thereby shifting the focus from rehabilitation to prehabilitation medicine, as a public service to several Japanese towns.

Flow-through anastomosis using a T-shaped vascular pedicle for gracilis functioning free muscle transplantation in brachial plexus injury.

OBJECTIVE: In gracilis functioning free muscle transplantation, the limited caliber of the dominant vascular pedicle increases the complexity of the anastomosis and the risk of vascular compromise. The purpose of this study was to characterize the results of using a T-shaped vascular pedicle for flow-through anastomosis in gracilis functioning free muscle transplantation for brachial plexus injury. METHODS: The outcomes of patients with brachial plexus injury who received gracilis functioning free muscle transplantation with either conventional end-to-end anastomosis or flow-through anastomosis from 2005 to 2013 were retrospectively compared. In the flow-through group, the pedicle comprised a segment of the profunda femoris and the nutrient artery of the gracilis. The recipient artery was interposed by the T-shaped pedicle. RESULTS: A total of 46 patients received flow-through anastomosis, and 25 patients received conventional end-to-end anastomosis. The surgical time was similar between the groups. The diameter of the arterial anastomosis in the flow-through group was significantly larger than that in the end-to-end group (3.87 mm vs. 2.06 mm, respectively, p<0.001), and there were significantly fewer cases of vascular compromise in the flow-through group (2 [4.35%] vs. 6 [24%], respectively, p=0.019). All flaps in the flow-through group survived, whereas 2 in the end-to-end group failed. Minimal donor-site morbidity was noted in both groups. CONCLUSIONS: Flow-through anastomosis in gracilis functioning free muscle transplantation for brachial plexus injury can decrease the complexity of anastomosis, reduce the risk of flap loss, and allow for more variation in muscle placement.

Ischemic injury to the brachial plexus following subclavian flap aortoplasty.

An ischemic brachial plexus lesion developed 6 days postoperatively in an infant undergoing subclavian flap aortoplasty for coarctation. To our knowledge, this complication has never been previously reported. Types of postoperative brachial plexus lesions are discussed. The blood supply to the brachial plexus is described. An ischemic lesion of the plexus should be suspected when brachial palsy follows operations that involve sacrifice of the subclavian artery.

Angiosomes of the brachial plexus: an anatomical study.

This anatomical study analyzed the neurovascular relationships of the brachial plexus. Ten fresh cadaveric brachial plexuses were examined after injection of the arterial system. The vascular anatomical features of the brachial plexus were documented with microdissection after lead oxide/gelatin injection. The specimens were analyzed by using radiography (including digital subtraction techniques) and light-microscopic, macroscopic, and digital photography. Four angiosomes, based on the subclavian, axillary, vertebral, and dorsal scapular arteries, were observed. As noted in previous angiosome studies, connections between angiosome territories lay within tissues, in this case, nerve trunks. Nutrient vessels penetrated nerve trunks at points of branching within the brachial plexus, with a Y-shaped mode of division on entry. The vascular supply was markedly rich, often with true anastomotic connections occurring within the nerves. There was much variation in supply, depending on the vascular anatomical features of the subclavian artery.

Posterior subscapular approach for specific brachial plexus lesions.

The surgical technique for exposure of the brachial plexus via a posterior subscapular approach is reviewed, with its relevant anatomy. The author has used this approach for four brachial plexus procedures. The indications for this approach will be discussed, and a case history presented to illustrate the benefits of this procedure in recurrent thoracic outlet syndrome.

Vascularised nerve grafts.

Since Taylor (1976) successfully performed the first vascularised free nerve graft, experimental and clinical data have not provided conclusive support for the superiority of this method of repairing loss of nerve substance. Experimental work yields conflicting results. Histologic results are in favour of vascularised grafts but non-vascularised fascicular grafts placed in a healthy bed recover sufficient neovascularisation within a short period of time (four to six days). In the field of brachial plexus repair, vascularised grafts give consistent results. However, if thrombosis of the anastomoses occurs, the grafts fail completely. In our experience, vascularised nerve grafts used for repairing digital nerves and arteries, have a high rate of thrombosis. There are few potential donor sites. A nerve graft cannot be considered to be physiologically vascularised if it relies only on an artery or on an arterialised vein. Given the present state of immunosuppressant treatments, vascularised allografts are not yet appropriate. Therefore, vascularised nerve grafts have limited applications. In general it is preferable to repair the tissue bed so as to promote revascularisation of conventional nerve grafts.