Cutaneous vasculature of the forearm

Five fresh human cadavers were injected with lead oxide, gelatin, and water. Nine forearms were dissected and an overall map of the cutaneous vasculature by source vessel was constructed. The average number of arterial perforators per source vessel was calculated. The forearm was then divided into three regions, and the density of perforators per region was calculated and compared. The overall number of arterial perforators decreases from proximal to distal in the forearm, but the overall density of perforators 0.5 mm or larger remains uniform. It was observed that the distal third of the forearm has a rich supply of smaller caliber arterial perforators compared with the proximal two-thirds of the forearm. The angiographic studies demonstrate a series of arterial perforators arising from the radial and ulnar arteries. The perforators in turn are linked longitudinally with other perforators from the same source vessel and transversely with the other major vessel. An understanding of this pattern of arterial supply of the forearm integument is helpful for the design of pedicled skin flaps and perforator flaps in the forearm.     

Analysis of flow changes in forearm arteries after raising the radial forearm flap: a prospective study using colour duplex imaging.

The purpose of this study is to assess the changes in flow patterns of forearm arteries produced by excision of the radial artery when harvesting the radial forearm flap, in order to clarify its vascular morbidity rationally. Eleven patients with elective surgery using the radial flap were included in this investigation. A prospective study was designed using colour duplex imaging for quantitative flow measurement in two stages: a few days before the operation, a first colour duplex scanning examination was done recording flow velocity and vessel section area from the radial, ulnar, posterior interosseous and anterior interosseous arteries around the wrist. Volumetric parameters and relative blood flow percentages were calculated and compared to those obtained from a second similar vascular investigation accomplished in the same limb 4-5 months after the operation. Statistical analysis was done using the Wilcoxon matched pairs test. After raising the radial forearm flap there was a trend for increased overall forearm flow (from 162 to 215 ml/min, P = 0.09 N.S.), the ulnar (P = 0.04), the posterior interosseous (P = 0.004) and the anterior interosseous (P = 0.003) arteries being responsible for this tendency. The anterior interosseous artery showed the greatest increase in blood (from 8.2 to 67.7 ml/min), reaching a relative flow percentage (33%) close to that of the radial artery before its excision (39%). Results of this study indicate that another 'major vascular axis' based on the anterior interosseous artery develops after sacrificing the radial artery and that global arterial inflow to the hand is not impaired.     

Vascular access in patients with arterial insufficiency. Construction of proximal bridge fistulae based on inflow from axillary branch arteries.

Patients with renal failure and underlying peripheral vascular disease pose a difficult management problem in establishing long-term angioaccess for chronic hemodialysis. This report summarizes our experience with five debilitated patients who developed acute upper extremity ischemia after forearm fistula construction corrected by fistula ligation. Successful angioaccess was achieved without ischemia recurrence by construction of proximal bridge fistulae with arterial inflow based on branch arteries of the axillary artery. The relatively small size of the branch vessel was the main factor in limiting fistula flow while permitting normal distal axillary artery flow. In four patients direct fistula flow measurements ranged from 200 mL per minute to 620 mL per minute. Axillary arterial flow distal to the fistula ranged from 120 to 200 mL per minute and did not significantly change after fistula construction or during temporary occlusion of the fistula. Four of the five patients continue to dialyze uneventfully from 4 to 8.5 months. One patient died after discontinuation of dialysis 1 month after operation.     

Arterial vasculopathy in systemic sclerosis: Computerized tomography (CT) angiographic features of macrovascular and microvascular upper limbs arteries

ObjectiveTo describe the CT angiographic findings of arterial vasculopathy in the major vessels as well as medium and micro vascular affection of the whole upper limbs arterial tree in patients with systemic sclerosis (SSc) with and without digital ulceration.MethodsTwenty-two cases with systemic sclerosis (12 limited and 10 diffuse) were recruited for the study. All patients fulfilled the American Rheumatism Association (ACR) criteria for the classification of SSc. For all patients routine laboratory investigations were performed including complete lipid profile. Computed tomography angiography (CTA) studies for the whole upper limb arterial tree were performed for both upper limbs in all cases.ResultsCTA studies showed involvement of subclavian arteries in 3 cases and axillary artery was involved in five cases. Brachial artery was affected in 5 cases. In the forearm the radial artery was affected in 4 cases with bilateral involvement in two cases (6 vessels), while ulnar artery was affected in five cases. Unilateral non visualization of the superficial palmar arch was observed in two cases with limited disease, while thinning out of the vessel wall with poor distal run off in 18 cases. A higher number of arterial vasculopathy was significantly associated with systolic pulmonary artery pressure (P = 0.001).ConclusionsMacrovascular arterial vasculopathy of upper limbs may occur in SSc irrespective of the disease pattern. Major arteries can be affected in association with other medium sized arteries of the forearms and microvascular arterial branches of the hands.     

CENTRAL HAEMODYNAMIC AND FOREARM VASCULAR EFFECTS OF MORPHINE IN PATIENTS AFTER OPEN HEART SURGERY

Central haemodynamic and forearm vascular changes followingadministration of morphine i.v. were studied in patients 24–30h after open heart surgery. Right atrial pressure, heart rate,mean arterial pressure, cardiac output and stroke volume weremeasured before and after morphine 5 and 10 mg per 70 kg in14 subjects. In a further group of eight subjects, forearm bloodflow was measured after morphine 10 mg per 70 kg. Total systemicand forearm vascular resistance were derived from these measurements.In spite of wide individual variations, significant decreasesin mean arterial pressure occurred in most of the patients andappeared to be dose related. Significant decreases in mean cardiacindex were noted only after morphine 10 mg per 70 kg. Forearmblood flow increased consistently and significantly and therewas a corresponding decrease in vascular resistance. The decreasein mean arterial pressure and the change in forearm vascularresistance indicated that vasodilatation was probably the principlecause of the decrease in arterial pressure, whereas the substaineddecrease in cardiac output seemed to indicate an effect on venouscapacitance. The predominant action of morphine appears to beperipheral, causing a decrease in vascular resistance and, possibly,an increase in venous capacitance. ^* Present address: Izaac Walton Killam Hospital for Children,Halifax, Nova Scotia, Canada.     

The Transposed Forearm Loop Arteriovenous Fistula: A Valuable Option for Primary Hemodialysis Access in Diabetic Patients

The distal forearm is the site of first choice for creation of an arteriovenous fistula for hemodialysis. The archetypal procedure, the primary radial-cephalic fistula as described by Brescia, yields excellent functional patency for many patients. Results are much less favorable in patients with diabetes mellitus, for whom non-maturation rates as high as 70% have been reported. This is likely due to inadequate inflow caused by atherosclerotic disease of the forearm arteries in diabetics. Secondary autologous access procedures often involve upper arm configurations such as transposed brachial-basilic fistulas. The present study focuses on a valuable alternative for hemodialysis access in diabetic patients, the transposed forearm loop arteriovenous fistula. Over a 2-year period, 16 forearm loop fistulas were created in 16 diabetic patients who either had a failed radial-cephalic fistula or had arterial anatomy deemed inadequate for wrist fistula formation. In each case, the forearm segment of the basilic or cephalic vein was transposed to form a U-shaped loop and anastomosed to the brachial, proximal radial, or proximal ulnar artery distal to the antecubitai fossa. Functional patency was defined as usability for dialysis. Patency rates were calculated by Kaplan-Meier survival analysis. From our results we determined that the forearm loop fistula is an excellent but underutilized technique that exploits the forearm veins while circumventing the distal arterial supply, thus preserving the upper arm vasculature for future use.     

Muscle glucose uptake does not increase when only local arterial glucose concentration is increased

Published models of mammalian whole-body glucose metabolism generally assume that glucose uptake is proportional to circulating glucose concentration at constant insulin concentration. One widely used model labels the increased whole-body glucose uptake seen with increased venous glucose concentration as "glucose effectiveness." In 1956 and 1957, we found on average no change in forearm glucose uptake when we doubled, or more than doubled, local forearm arterial glucose concentration by close arterial infusion so that pancreatic arterial glucose concentration did not change. These experiments are being reported in extenso for the first time. Since that time, two other groups have found in glucose/insulin clamp experiments that whole-body glucose uptake was not proportional to hyperglycemic concentrations, although uptake did increase. It was hypothesized that perhaps some organs and tissues do increase uptake proportionally and other tissues not at all. Our results show that skeletal muscle is a tissue in which glucose uptake, at constant insulin, is not changed acutely by hyperglycemia; there is no forearm glucose effectiveness. We suppose that this constancy occurs because there are so few GLUTs on the sarcolemma surface in the basal state and that they are saturated even at euglycemia. We also report earlier experiments from 1954 to 1955 in which comparable hyperglycemia was reached by a large oral dose of glucose, with a 10-fold increase in glucose uptake. The arterial glucose time curve during hyperglycemia was 20-30 mg/dl higher than the forearm venous curve.     

The effects of propofol and thiopentone on forearm circulation

Some effects of propofol and thiopentone induction on the peripheral circulation of healthy patients are examined using mercury strain gauge venous occlusion plethysmography of the forearm. Results indicate that both drugs produce a statistically significant decrease in mean arterial blood pressure and forearm blood flow. Forearm vascular resistance remains unchanged after either drug. These data suggest that bolus dose induction of anaesthesia with propofol does not cause arterial vasodilatation of the limb and that a cause for the reduction in mean arterial pressure must be sought elsewhere.     

Acute penetrating arterial injuries of the forearm. Ligation or repair?

The management of forearm arterial trauma is controversial and follow-up data on such injuries is scant. A survey was made of 249 patients with penetrating forearm trauma to determine the incidence and outcome of arterial injury. Sixty-six patients (26.5%) sustained 69 arterial injuries documented at operation or with angiography. The clinical manifestations of arterial injury were often subtle; 42.4 per cent of the patients had normal pulses and only 7.6 per cent presented with distal ischemia. In 9.1 per cent of the patients there was no clinical evidence of vascular injury. The most frequent types of arterial injury were transection (72.5%) and partial laceration (14.5%). Arterial repair was performed in 84.8 per cent of the cases, and resection with end-to-end anastomosis was usually possible. Volar compartment fasciotomies were necessary in 18.2 per cent of the cases. The early postoperative complications seen were wound-related, and these were six times more frequent in the group undergoing arterial ligation (36% vs 6%). In 49 patients evaluated an average of 6 months after repair, the patency rate determined by clinical examination was 85.7 per cent. Because of a high incidence of associated nerve (56.1%) and tendon (54.5%) injuries, the functional status of the injured extremity was less satisfactory, with only 49.2 per cent of the patients having normal hand function. Since the forearm vessels can be repaired with minimal morbidity and acceptable results, arterial ligation is recommended only when repair is not readily accomplished, or when treatment of a more pressing associated injury demands priority.     

Aberrant branch of the radial artery encountered during elevation of the radial forearm free flap

Although the radial arterial system is fairly consistent in structure, rare anomalies have been encountered. During the elevation of a radial forearm free flap for floor of mouth reconstruction, the authors have encountered an accessory branch of the radial artery arising from the main radial artery at the level of the mid forearm, extending laterally over the brachioradialis muscle, and descending into the dorsal wrist in the subcutaneous plane. This artery, named as the superficial radial artery, is a very rare vascular anomaly of the radial arterial system in the forearm. The reconstructive surgery literature is relatively silent about this particular variant. Knowledge of possible anatomic anomalies and careful identification of vessels are important to prevent damage to the arterial system and enable optimal flap harvest.     

A forearm free flap based on an occluded radial artery: its salvage and avoidance

The salvage of a radial forearm free flap based on an occluded radial artery is reported. Circulation to the flap was restored by resection and reconstruction of the nonpatent arterial segment within the flap. A simple test is recommended for preoperative assessment of forearm radial artery patency in which proximal pulsation is felt after distal compression of the radial artery at the wrist.     

Anomalous superficial ulnar artery based flap

Upper limb shows a large number of arterial variations. This case report describes the presence of additional superficial ulnar artery which was used to raise a pedicle flap to cover an arm defect thus avoided using the main vessel of the forearm - radial or ulnar artery. Vascular anomalies occurring in the arm and forearm tend to increase the likelihood of damaging the superficial anomalous arteries during surgery. Superficial ulnar or radial arteries have been described to originate from the upper third of the brachial artery; here we report the origin of the anomalous superficial ulnar artery originating from the brachial artery at the level of elbow with the concomitant presence of normal deep radial and ulnar arteries.KEY WORDS: Anomalous artery based flap, arterial variations of the forearm, superficial ulnar artery based flap     

Patency of radial arteries reconstructed after radial forearm flap harvest

Poor patency is cited as a reason to not perform radial artery reconstruction after the harvest of the radial forearm flap. The need for a long vein graft and the presence of a patent ulnar artery are offered as explanations for thrombosis of the reconstruction in this setting. Similar arguments have been made regarding radial artery reconstruction in the trauma setting. In this study, the patency rate for patients undergoing radial forearm flap harvest with immediate reconstruction with reversed interposition vein grafting was evaluated. The mean follow-up time was 24 months, and all seven patients had patent reconstructions. Ultrasound examination revealed slightly larger diameters of the vein grafts compared with native arteries. No areas of stenosis were detected. No complications resulted from harvest of the vein. From these data, we conclude that radial artery reconstruction can be performed with the expectation of patency.     

Transcutaneous blood flow measurements in arteries of the human hand

Technical advances in twenty MHz pulsed ultrasonic Doppler velocimetry (PUDVM) permit increasingly accurate measurements of blood flow in small vessels. This study applied advanced twenty MHz PUDVM methods to the transcutaneous, noninvasive quantitation of blood flow in arteries of the human hand. One hundred forty-four measurements were completed bilaterally in the digital arteries of all fingers and in the distal radial and ulnar arteries of the forearm. The data were averaged by artery for maximum velocity and average volumetric flow. The maximum velocity for digital and forearm arteries was about 20 centimeters per second and 50 centimeters per second, respectively. The average volumetric flow for these same arteries was about 0.02 cubic centimeters per second and 0.18 cubic centimeters per second, respectively. Statistical analysis demonstrated no differences between paired, contralateral arteries; within given fingers a difference occurred only between the radial and ulnar arteries of the index finger.     

Vascular responsiveness to brachial artery infusions of phenylephrine during isoflurane and desflurane anesthesia

Compared with equi-minimum alveolar anesthetic concentration (MAC) isoflurane, desflurane is associated with greater levels of sympathetic nerve activity in humans but similar reductions in blood pressure. To explore these divergent effects, we evaluated vascular alpha(1)-adrenoceptor responses in the human forearm during isoflurane and desflurane anesthesia to determine if alpha(1)-adrenoceptor responses were more substantially attenuated during desflurane administration. Bilateral forearm venous occlusion plethysmography was used to examine arterial blood flow and to determine changes in forearm vascular resistance during brachial artery infusions of saline and phenylephrine (0.2, 0.4, 0.8, and 1.6 microg/min) in 22 conscious subjects and during anesthesia with 0.65 and 1.3 MAC isoflurane or desflurane. Infusion of phenylephrine into the brachial artery increased the forearm vascular resistance in a dose-dependent manner. The arterial response to phenylephrine was significantly attenuated by 0.65 and 1.3 MAC desflurane and similarly attenuated during 1.3 MAC isoflurane (P < 0.05). Impaired arterial alpha(1)-adrenoceptor responsiveness occurred during desflurane. However, this effect was statistically similar (P > 0.05) to the impaired responses during isoflurane. Blood pressure decreases during volatile anesthesia may be, in part, caused by decreased alpha(1)-adrenoceptor responsiveness. IMPLICATIONS: alpha-receptors on blood vessels regulate constriction and dilation and therefore modulate blood pressure. This research indicates that vasoconstriction via the alpha(1)-receptor vascular response is impaired during isoflurane and desflurane anesthesia.     

Surgical treatment of transposition of the great arteries with bilateral intramural coronary arteries

A 33-day-old neonate with transposition of the great arteries, ventricular septal defect, and intramural course of both coronary arteries underwent successful arterial switch repair. At a follow-up time of 36 months, left ventricular function and coronary arterial anatomy at angiography were normal. Optimal treatment of such rare coronary arterial abnormality may allow functional and anatomic results comparable to usual coronary arterial patterns in transposition of the great arteries.     

应用前臂游离皮瓣折叠法修复大型腭部洞穿性缺损

目的 探讨大型腭部洞穿性缺损修复的方法.方法 2003年至2006年,我们应用前臂游离皮瓣折叠法为7例患者进行了腭部洞穿性缺损修复,共使用皮瓣8块,其中前臂游离皮瓣7块,胸大肌岛状瓣1块.结果 除1例前臂游离皮瓣因动脉栓塞失败外,其余组织瓣完全成活,再造腭部形态良好.患者可经口腔正常进食,并进行基本正常的语言交流.结论 利用前臂游离皮瓣折叠法进行大型腭部洞穿性缺损的修复,是一种有效可行的方法.     

Persistent Median Artery As A Cause Of Nonmaturing AV Fistula

A 68‐year‐old right handed male with End‐Stage Renal Disease with a left radiocephalic fistula created 8 months ago was referred for the evaluation of a nonmaturing access. Patient had an arterial anastomosis lesion that underwent successful angioplasty. Diagnostic arteriogram of the AV access extremity revealed the presence of a short radial artery and dominant common interosseous artery manifesting as a persistent median artery in the distal forearm and was anastomosed to the fistula and then continues as the median‐ulnar superficial arch in the palm. Balloon angioplasty of the common interosseous artery led to a complication when the distal 30 cm of the 0.018 guide wire fractured and had to be retrieved using a snare device. In addition to anticipating and treating the common complications of vascular access procedures, it is also important to be aware of the anomalies of the distal forearm arterial anatomy and perform a detailed arterial evaluation prior to creating the arterio‐venous anastomosis.     

Skeletal Muscle Oxygen Pressure Fields in Artificially Ventilated, Critically 111 Patients

The MDO (Mehrdraht Dortmund Oberfläche) oxygen electrode was used in a study of skeletal muscle oxygen pressure fields. presented as histograms, in critically ill patients artificially ventilated with gas mixtures of different oxygen concentrations. The histograms were compared with forearm blood flow measurements performed with strain gauge plethysmography. Local blood flow and permeability-surface area product (PS) were also studied by the simultaneous clearances of ¹³³xenon and ⁵¹ Cr-EDTA. The histogram distribution type was normal, i.e. approximately Gaussian, at arterial oxygen pressure levels between 10 and 18 kPa. At arterial oxygen pressures outside this range the histogram distribution types were abnormal, i.e. they showed a nonsymmetrical distribution of oxygen pressure values, but their mean was approximately the same as in the normal histogram. However, there were significantly higher tissue oxygen pressure mean values in the patients (3.43 kPa) than in a group of healthy human volunteers (2.25 kPa). Mean forearm blood flow and the clearances of ¹³³ xenon and ⁵¹ Cr-EDTA showed marked variations during the measurements both intraindividually and interindividually. Mean forearm blood now and mean clearances of¹³³ xenon showed opposite trends compared with arterial oxygen pressures. Mean clearances of ⁵¹ Cr-EDTA and mean PS showed only minor variations at the different arterial oxygen pressure levels.     

Forearm arterial venous shunt for hemodialysis

A new technique for creation of an arterial venous shunt for hemodialysis is described. The proximal radial artery is used for the arterial inflow anastomosis site instead of the brachial artery. The technique provides an adequate arterial inflow but avoids all the complications of utilization of the brachial artery in the forearm arterial venous shunt for hemodialysis.