Clinical anatomy of the subcutaneous veins in the dorsum of the hand

Anatomical characterization of acupoint large intestine 4

Large intestine 4 (LI4) is a major acupoint used in various treatments in acupuncture and Traditional Chinese Medicine. There are structures associated within the region of LI4 that have three-dimensional anatomical relationship that needs further characterization. The aims of this study were: (a) to observe the anatomical variation of structures around LI4; (b) to observe specific overlap of structures around LI4. A 1256 mm² area was dissected in 25 cadaveric hands around LI4. Nondissected areas were marked with pins as reference points. Dissections were photographed with a fixed camera. Subsequently, images were imported to Adobe Photoshop 2020 and analyzed. Descriptive statistics and graphs were compiled using Graphpad Prism 2020. The tributaries of the dorsal venous plexus (22.3%), branches of superficial radial nerve (18.9%), first dorsal interosseous muscle (52.4%), arterial branches in the first interosseous space (10.2%), and deep ulnar nerve (4.0%) were observed in the area of LI4. One branch of the superficial radial nerve passed through LI4. The deep ulnar nerve was found in the bulk of the first dorsal interosseous muscle. Several structures observed intersected at LI4. The superficial radial nerve interweaved with the dorsal venous plexus superficially. The deep ulnar nerve passed anterior to the second palmar metacarpal artery before entering into the first dorsal interosseous muscle. These results provide anatomical evidence and variation into the vascular contributions at LI4.

ADVIT: Using the potentials of deep representations incorporated with grid-based features of dorsum vein patterns for human identification

The identification of an individual is one of the main applications of forensic science, used in legal settings for deciding cases in courts of law. Different methods have been developed for the identification of a person, including fingerprints, DNA profiling, retina scan, facial features and many others. The reliable and accurate identification mainly relies upon substantial variability of structures and features of evidence corresponding to reference material. During the last decade, human identification through hand vein patterns has been focused in various studies and shown promising results. However, most of the reported methods require extensive human efforts for manual feature calculation. Herein, we propose a novel identification tool namely ADVIT for the identification of humans based on their dorsum veins pattern. The samples of the dorsum of the right or left hand were collected from 50 participants in the form of images. Initially, images were preprocessed and noise (in terms of hair on the skin and other details) was removed. Later on, the vein skeleton was extracted from the preprocessed images and a binary image of veins pattern (veins in the foreground and every other detail as background) was generated. Two different types of the feature were computed and based on these features, three different experiments were performed and the evaluation metrics were computed. Merging of hand-crafted grid-based features and deep representation from RESNET-50 showed maximum results in terms of Sensitivity (0.8803), Specificity (0.8890), Precision (0.8849), False Positive Rate (0.1074), Accuracy (0.8861), F1 Score (0.8817), and MCC (0.7636). These results depicted that the model is accurate and sensitive for identification through dorsum veins pattern. The proposed model can aid forensic scientists to identify perpetrator using hand images. ADVIT is freely available at (http://zeetu.org/advit.html).

A simple approach to use hand vein patterns as a tool for identification

INTRODUCTION

In a case of child pornography, only the dorsum of the offender's hand was clearly visible. After identification of a suspect, the question arose of whether and how it is possible to identify or exclude the suspect as perpetrator according to the morphology of the hand vein pattern.

MATERIAL AND METHODS

A simple approach to use the hand vein pattern in crime suspects as a tool for identification was tested. In this study, the hand vein patterns of 30 study participants were analysed from conventional frames on videography. A standardised grid system consisting of six lines and four sectors was applied on the dorsum of the hands. Vein branchings within the sectors and line crossings of the veins were counted, leading to a total of 11 variables for each hand.

RESULTS

A positive identification of each of the 30 test participants was possible for each hand when taking only the first five variables into account. A random overlapping prediction was obtained by statistically simulating hand vein patterns of different numbers of persons using this sample. Considering the hand vein frequencies in this sample, the results indicate that the chance for two persons having the same pattern is smaller than 1:1000.

CONCLUSIONS

It can be concluded that the introduced grid system approach can be an appropriate simple and non-costly tool for the analysis of the pattern of hand veins for identification purposes.

The best vein to be accessed based on descriptive study of dorsal metacarpal vein

It is well known that the most common sites for venous access are the superficial veins of the upper limb, particularly dorsal metacarpal veins and median cubital vein. Although dorsal metacarpal veins are the first choice for venous cannulation, there is scarce information about their anatomic variation. Hence, detailed anatomical information about these veins will improve the anatomic knowledge of the health care providers. Subsequently, this study was designed to study the dorsal metacarpal veins and to determine the most prominent dorsal metacarpal vein. A cross sectional study of 402 subjects (804 hands), was prepared to study the superficial veins on the dorsum of the hand among Jordanian students and staff of one of the major governmental medical colleges in Jordan, by using infrared illumination system. The obtained data was analyzed according to sex, sidedness, and handedness. Six locations of the most prominent dorsal metacarpal veins were identified. There was a significant relation between both females and males and the most prominent dorsal metacarpal vein (P=0.01). For the first time this study identified the most common location of the most prominent dorsal metacarpal vein in the fourth intermetacarpal space.

The Superficial Venous System of the Forelimb of the Anubis Baboon (Papio anubis): The Distribution of Perforating Veins and Venous Valves

The superficial veins of the forelimb show high variability, both in man and in other primates, regarding the number of main venous trunks, their course, as well as the origin and location of openings. The distinction between two venous systems–the superficial and deep was made based on the relation of specific venous channels to the deep fascia; both groups of veins anastomose to each other through perforators piercing the deep fascia. In our work, we paid special attention to the organization of the venous system within the forelimb of the Anubis baboon (Papio anubis), as well as communications between the superficial and deep venous system. The main aim of the study was a detailed examination of the location of venous valves and perforating veins in forelimb of Anubis baboon. In the Anubis baboon, we observed the absence of the basilic vein. The main vessel within the forelimb, in the superficial venous system, was a well-developed cephalic vein. In all the cases, the cephalic vein opened into the external jugular vein. Also, in all of the examined specimens, there was an additional anastomosis connecting the cephalic and external jugular vein, i.e., persistent jugulocephalic vein located anterior to the clavicle. The venous vessels in the Anubis baboon were arranged in two main layers: superficial and deep, with both systems being connected by perforators located at the level of the carpus and cubital fossa. The number of venous valves within the cephalic vein was greater on the forearm the same as the mean intervalvular distance.

Hands and feet: physiological insulators, radiators and evaporators

The purpose of this review is to describe the unique anatomical and physiological features of the hands and feet that support heat conservation and dissipation, and in so doing, highlight the importance of these appendages in human thermoregulation. For instance, the surface area to mass ratio of each hand is 4-5 times greater than that of the body, whilst for each foot, it is ~3 times larger. This characteristic is supported by vascular responses that permit a theoretical maximal mass flow of thermal energy of 6.0 W (136 W m(2)) to each hand for a 1 °C thermal gradient. For each foot, this is 8.5 W (119 W m(2)). In an air temperature of 27 °C, the hands and feet of resting individuals can each dissipate 150-220 W m(2) (male-female) of heat through radiation and convection. During hypothermia, the extremities are physiologically isolated, restricting heat flow to <0.1 W. When the core temperature increases ~0.5 °C above thermoneutral (rest), each hand and foot can sweat at 22-33 mL h(-1), with complete evaporation dissipating 15-22 W (respectively). During heated exercise, sweat flows increase (one hand: 99 mL h(-1); one foot: 68 mL h(-1)), with evaporative heat losses of 67-46 W (respectively). It is concluded that these attributes allow the hands and feet to behave as excellent radiators, insulators and evaporators.

Gravitational retrograde venous perfusion--a technique for limb extremity salvage when microvascular arterial repair is not possible

Occasionally in plastic surgery immediate microvascular arterial repair is not possible. This occurs when distal vessels in the extremities are extensively damaged or thrombosed. If there is some intact venous anatomy it may be possible to maintain adequate perfusion for viability using a gravitational retrograde venous perfusion technique, until collateral arterial supply develops. We have used this technique successfully in three cases--blast injury to the hand, extensive digital thromboembolism and a devascularised sole of foot. This technique involves elevating and lowering the limb at 30 min intervals for 5-7 days. Elevation results in venous drainage and pallor of the limb and dependency results in venous congestion confirming retrograde venous flow. In the authors' experience ischaemic necrosis was inevitable in these cases without the use of this new technique. We have attempted to explain this phenomenon by way of retrograde venous perfusion in association with high venous pressure and high oxygen tension.

Venous pumps of the hand. Their clinical importance

Oedema remains one of the most common causes of hand stiffness. Local venous return is intimately associated with oedema formation and management. To elucidate the underlying mechanisms of venous return, the venous pumping systems in the hand were objectively and quantitatively investigated using Doppler ultrasound, cadaveric dissection and venography. It was demonstrated that functionally there are three independent venous systems: the superficial palmar, deep palmar and dorsal veins, which are activated by palm compression, isometric intrinsic muscle contraction, and dorsum compression, respectively. Each system was investigated independently and found to increase venous blood velocity in both the cephalic and ulnar veins. These systems were also shown to act in synergy, producing the greatest velocity increase when concurrently activated during fist-clenching. The volume of blood pumped during fist-clenching could also be potentiated by preloading by digit abduction. The clinical applications of these findings are discussed.