Unilateral high origin of radial artery from axillary artery

Variations in the vascular system of upper limbs are relatively common, with considerable significance towards the clinical and surgical point of view. The major arterial variations reported are of high origins of radial and ulnar arteries. During routine dissection of an upper extremity in the Department of Anatomy, Medical University of the Americas, Nevis, West Indies, a variation in the origin of the radial artery from the axillary artery was observed in the right upper limb of a 55-year-old female cadaver. The normal and variant origin of the radial artery has pragmatic importance for surgeons and radiologists. Also, the superficial position of an artery makes it vulnerable to injury during cannulation, which may lead to pseudoaneurysm.

Patient-specific computational modeling of upper extremity arteriovenous fistula creation: its feasibility to support clinical decision-making

Introduction

Inadequate flow enhancement on the one hand, and excessive flow enhancement on the other hand, remain frequent complications of arteriovenous fistula (AVF) creation, and hamper hemodialysis therapy in patients with end-stage renal disease. In an effort to reduce these, a patient-specific computational model, capable of predicting postoperative flow, has been developed. The purpose of this study was to determine the accuracy of the patient-specific model and to investigate its feasibility to support decision-making in AVF surgery.

Methods

Patient-specific pulse wave propagation models were created for 25 patients awaiting AVF creation. Model input parameters were obtained from clinical measurements and literature. For every patient, a radiocephalic AVF, a brachiocephalic AVF, and a brachiobasilic AVF configuration were simulated and analyzed for their postoperative flow. The most distal configuration with a predicted flow between 400 and 1500 ml/min was considered the preferred location for AVF surgery. The suggestion of the model was compared to the choice of an experienced vascular surgeon. Furthermore, predicted flows were compared to measured postoperative flows.

Results

Taken into account the confidence interval (25^th and 75^th percentile interval), overlap between predicted and measured postoperative flows was observed in 70% of the patients. Differentiation between upper and lower arm configuration was similar in 76% of the patients, whereas discrimination between two upper arm AVF configurations was more difficult. In 3 patients the surgeon created an upper arm AVF, while model based predictions allowed for lower arm AVF creation, thereby preserving proximal vessels. In one patient early thrombosis in a radiocephalic AVF was observed which might have been indicated by the low predicted postoperative flow.

Conclusions

Postoperative flow can be predicted relatively accurately for multiple AVF configurations by using computational modeling. This model may therefore be considered a valuable additional tool in the preoperative work-up of patients awaiting AVF creation.

Validation of a power law model in upper extremity vessels: potential application in ultrasound bleed detection

Vascular ultrasound can provide quick and reliable diagnosis of arterial bleeding but it requires trained and experienced personnel. Development of automated sonographic bleed detection methods would potentially be valuable for trauma management in the field. We propose a detection method that (1) measures blood flow in a trauma victim, (2) determines the victim's expected normal limb arterial flow using a power law biofluid model where flow is proportional to the vessel diameter taken to a power of k and (3) quantifies the difference between measured and expected flow with a novel metric, flow split deviation (FSD). FSD was devised to give a quantitative value for the likelihood of arterial bleeding and validated in human upper extremities. We used ultrasound to demonstrate that the power law with k = 2.75 appropriately described the normal brachial artery bifurcation geometry and adequately determined the expected normal flows. Our metric was then applied to three-dimensional (3-D) computational models of forearm bleeding and on dialysis patients undergoing surgical construction of wrist arteriovenous fistulas. Computational models showed that larger sized arterial defects produced larger flow deviations. FSD values were statistically higher (paired t-test) for arms with fistulas than those without, with average FSDs of 0.41 ± 0.12 and 0.047 ± 0.021 (mean ± SD), respectively. The average of the differences was 0.36 ± 0.12 (mean ± SD).

A morphological study of variations in the branching pattern and termination of the radial artery

INTRODUCTION

Coronary artery bypass grafting is an established means of treating advanced coronary artery disease. In recent years, there has been an increased interest in the radial artery as an entry route during coronary angiography. Accurate knowledge of the branching pattern of this artery and its relation to surrounding structures is of great importance in the care of surgical patients.

METHODS

This study was conducted on 75 formalin-fixed upper limbs in order to note the variations in the branching pattern and termination of the radial artery.

RESULTS

The radial artery divided into three branches in 2.7% of cases and into two branches in 52.0% of cases. The radial recurrent artery originated from the brachial artery instead of the radial artery in 12.0% of cases. The radial recurrent artery, palmar carpal artery, first dorsal metacarpal artery and superficial palmar artery were absent in 1.3%, 26.7%, 9.3% and 5.3% of cases, respectively. 6.7% of cases had a high origin of the superficial palmar artery.

CONCLUSION

The rich photographic documentation of the variation of branching pattern and termination of radial artery is not only of academic interest but also useful to surgeons and radiologists working in the same area.

Diagnostic methods, treatment modalities, and follow-up of extracranial arteriovenous malformations

OBJECTIVE

Arteriovenous malformations (AVMs) are an uncommon vascular pathology that remains challenging to accurately diagnose and successfully treat. This study introduces a novel way to evaluate AVM treatment outcomes using transarterial lung perfusion scintigraphy (TLPS) and reports our treatment results.

MATERIAL AND METHODS

The patients treated for extracranial AVMs were studied retrospectively. Diagnosis and outcomes were based on clinical data, ultrasonography, magnetic resonance imaging, computed tomography, angiography, and TLPS studies. The influence of gender; location, form, and stage of AVMs; first attempt at treatment; and treatment modalities was analyzed. Outcomes were defined as positive (cure, improvement, and remission) or negative (no remission and aggravation).

RESULTS

Of the 324 patients with congenital vascular malformations, 129 (39.8%) presented with AVMs, and the data of 56 treated patients with AVMs were analyzed. Of the 29 patients in the endovascularly treated group, 15 in the surgically treated group, and 12 in the combined treatment group, 24 (82.8%), 14 (93.3%), and 10 patients (83.3%), respectively, had positive outcomes (P>0.05). All outcomes were positive in surgically treated patients with extratruncular limited AVMs, and these patients were more likely to be cured as compared with those who had other forms of AVMs (OR, 5.8; 95% CI, 1.1-29; P=0.02). The patients with more advanced AVMs (stages III and IV) and with AVMs in the gluteal and pelvic region were more likely to have the worst outcomes than those with stage II AVMs (OR, 8.2; 95% CI, 1-72; P=0.03) and with AVMS in other locations (OR, 5.8; 95% CI, 1.1-29; P=0.02), respectively. Gender and age did not significantly influence treatment results (P>0.05). The TLPS data of 17 patients showed AV shunting ranging from 0% to 92%, which combined with other results helped identify 9 patients who needed further interventions, 6 who were treated successfully, and 2 who had insignificant shunting.

CONCLUSIONS

The best outcomes were achieved in surgically treated patients with localized lesions and less advanced AVMs. For the first time in Lithuania, a modified TLPS method has been introduced that enhances a hemodynamic assessment of AV shunting and provides with a more accurate evaluation of AVMs to better serve in planning future treatments.

Outcomes of arteriovenous fistula for hemodialysis in Sudanese patients: single-center experience

A well-functioning arteriovenous fistula (AVF) is essential for the maintenance of hemodialysis (HD) in patients with chronic renal failure. Our aim is to review our experience of creating AVF and to asses its success rate and common complication. A prospective, hospital-based study was conducted on 73 patients (48 males and 25 females) on chronic HD in Gezira Hospital for Renal Diseases and Surgery, from January to July 2007. Their mean age was 43.9 years (range from 18 to 72 years). Seventy-one (97.3%) of the study subjects had been dialyzed before creation of the AVF, 67 (91.8%) of them having undergone HD with temporary access. All patients (n=73) had a native AVF as the permanent vascular access (VA). A primary radiocephalic AVF was created in 78.1% of the patients, cubital fossa in 20.5% and one case had left snuff box AVF (1.4%). Percentage of AVF maturation was reported in 67.1% of the cases within the first six weeks and in 9.6% of the cases AVF never matured. Failure of AVF function occurred in 26% of the cases, due to thrombosis in 20.5% (n=15) and aneurysm in 5.5% of the cases. We conclude that an optimum outcome is likely when there is a multidisciplinary team approach, and early referral to vascular surgery is paramount.

Predictors of early vascular-access failure in patients on hemodialysis

Vascular access management is key and critical in the successful management of hemodialysis patients, and an arteriovenous fistula (AVF) is considered the access of choice. This study was conducted between January 2007 and October 2009 at the Military Hospital in Rabat. Data on 115 patients who underwent 138 AVFs were retrospectively studied. Wrist AVF was the most common site of use. The primary course was uncomplicated in 63% of the patients, while primary failure occurred in 23.9% of the patients. Presence of diabetes was the most important risk factor for primary failure.

[Microcirculation blood flow of the upper extremities in patients with coronary artery disease combined with non-insulin dependent diabetes mellitus]

The work was aimed at assessing the possibilities of the microcirculatory blood flow (MBF) of the upper extremities in patients suffering from coronary artery disease (CAD), as well as in patients with CAD accompanied by type 2 diabetes mellitus (NIDDM) by means of laser Doppler flowmetry (LDF) using functional tests. The obtained findings of the study demonstrated that that the lowest reserve capabilities of the MBF were observed in the group of patients with CAD and NIDDM, and this group considerably more often versus patients with CAD without NIDDM showed decreased collateral reserve and low compensatory capabilities of the microcirculatory bed of the upper limbs.

Comparison between autogenous brachial-basilic upper arm transposition fistulas and prosthetic brachial-axillary vascular accesses for hemodialysis

AIM

The aim of this paper was to compare the outcomes of patients undergoing autogenous brachial-basilic upper arm transposition fistulas (BBAVF) with prosthetic brachial-axillary vascular accesses (BAPTFE) at immediate and medium follow-up.

METHODS

Retrospective analysis of the aforementioned accesses performed in a single-center from 2003 to 2007. Transposition was used in all BBAVF performed. Conic prostheses were used in the BAPTFE. Primary and secondary patency, patient survival, types of complications and its rates were assessed during follow-up.

RESULTS

Thirty-six BBAVF and 40 BAPTFE were performed. Both groups were well matched for age, gender and comorbidity. BBAVF primary patency was 93.5%, 50.4%, 45.8% and 45.8% compared to 80.6%, 64.3%, 46.2% and 31.6% of the BAPTFE group at 1, 12, 24 and 36 months of follow-up (P=0.719). BBAVF secondary patency was 93.5%, 50.4%, 45.8% and 45.8% compared to 80.6%, 67.7%, 54.2% and 35.1% of the BAPTFE at the same periods (P=0.902). Patient survival was 97.2%, 97.2%, 93.2% and 86.5 for BBAVF in contrast to 97.2%, 94.4%, 84.1% and 79.9% for BAPTFE in the same months (P=0.386). 13.8% of the BBVAF had accessibility problems while only 5% of the BAPTFE presented them (P=0.174). Infection was more frequent in BAPTFE (0% vs 10%), being the only complication near the statistical signification (P=0.071).

CONCLUSION

BBAVF offer patency and accessibility rates similar to BAPTFE, but lower infectious complications. Thus, we consider them as the preferred hemodialysis access when fistulas using the cephalic vein have failed or are not possible.

[Clinical case of the month. Upper extremity deep venous thrombosis]

According to the studies, approximately 4 to 10% of all the cases of deep venous thrombosis are located in the subclavian, axillary or brachial veins. The more frequent use of central venous catheters and pacemaker leads is probably responsible for their increasing incidence these last decades. The deep venous effort thrombosis also called Paget-Schroetter Syndrome is part of the spontaneous upper extremity venous thromboses. They mostly affect young adults who practice special kinds of sports or whose professions require repetitive arm movements. Colour Duplex sonography provides a simple and accurate tool for the diagnosis of upper extremity deep venous thrombosis. Nowadays venography and venoscan are no longer used for diagnostic purposes. These techniques are limited to venous thromboses including to the brachiocephalic vein or the superior vena cava. This pathology can have major clinical consequences including pulmonary embolism and post-thrombotic syndrome. However, the prevalence of pulmonary embolism is controversial (20-35% according to studies) and fatal PE is very rare. Post-thrombotic syndrome mostly consists of venous stasis syndrome and painful exertion. Low molecular weight heparin followed by oral anticoagulation are recommended. Thrombolysis is often successful, but less frequently used because of its potential risks. Surgery may be required in case of venous compression (eg in case of thoracic outlet syndrome).

Effect of local and remote ischemic preconditioning on endothelial function in young people and healthy or hypertensive elderly people

To verify whether age affects remote preconditioning, we compared healthy young people (mean age = 28.0 years, SD: 7.2), healthy elderly people (age = 69.2 years, SD: 5.0), and hypertensive elderly people (group 3, age = 72.8 years, SD: 3.9). Each group included 10 participants. The flow-mediated-dilation (FMD) was measured after local (same arm) and remote (leg) ischemic preconditioning. Healthy elderly people had the greatest increase of FMD after ischemic preconditioning compared to baseline (173% after local and 181% after remote preconditioning) and young participants the smallest increase (77% after local and 69% after remote preconditioning) while hypertensive elderly had an intermediate increase (P for comparison across groups: 0.347 for local and 0.064 for remote preconditioning). However, absolute values of FMD after preconditioning were much lower in elderly hypertensive than in healthy young adults. Remote preconditioning increases endothelial reactivity in healthy and hypertensive elderly. The potential clinical relevance of this finding deserves consideration.

High bifurcation of the brachial artery

Variations of the arterial pattern in the upper limb are quite common in humans. In the present study, we describe two cases of high bifurcation of the brachial artery. In the first cadaver both branches run superficially along the arm and were also located superficially at the antecubita fossa. In the second cadaver the branch that continues as the radial artery in the forearm run superficially and was located also superficially at the antecubita fossa, while the second branch had a more or less normal distribution. The embryological basis and clinical significance are discussed.

Axillary sheath hematomas causing neurologic complications following arterial access

Iatrogenic brachial plexus injuries secondary to expanding hematomas and pseudoaneurysms have been described in limited nature in previously published data. We present the case of a 55-year-old woman who developed neurologic deficits because of a compressive hematoma after axillary arteriography. She underwent emergent exploration of her left arm with decompression of the axillary sheath and brachial artery repair with complete recovery. We describe the presentation, relevant anatomy, and importance of this condition and stress the need for early recognition and surgical intervention to prevent permanent neurologic deficits.