Anatomic study of the venous drainage architecture of the forearm skin and subcutaneous tissue

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.

Echographic landmark of cephalic and collateral accessory vein at forearm in preoperative evaluation for hemodialysis angioaccess

INTRODUCTION

Superficial veins in the upper arm differ according to their relationship to the superficial fascia. We investigated the echographic landmark of the cephalic vein (CV) to correctly distinguish it from the collateral accessory vein (CAV) before hemodialysis angioaccess creation.

MATERIALS AND METHOD

Twenty consecutive patients were evaluated by ultrasonographic scan. The echographic features of CV and CAV together with their relationship were described.

RESULTS

Ninety-five percent of patients presented both CV and CAV (75% CAV laterally located, 25% medially located). CV and CAV diameters were 2.9 (±0.65) and 2.0 (±0.70), respectively.

CONCLUSIONS

CV differs from CAV for its anatomic location at forearm. Such a difference is clearly evident under ultrasound examination, despite any recommendation in ultrasound guidelines. Whether the exclusive use of CV for angioaccess creation can lead to a better outcome will be ascertained by further studies.

Necrotizing fasciitis: classification, diagnosis, and management

Necrotizing fasciitis (NF), a life-threatening rare infection of the soft tissues, is a medical and surgical emergency. It is characterized by subtle, rapid onset of spreading inflammation and necrosis starting from the fascia, muscles, and subcutaneous fat, with subsequent necrosis of the overlying skin. Once suspected, immediate and extensive radical debridement of necrotic tissues is mandatory. Appropriate antibiotics and intensive general support avoid massive systemic diffusion of the infective process and are the key for successful treatment. However, early diagnosis is missed or delayed in 85% to 100% of cases in large published series: because of the lack of specific clinical features in the initial stage of the disease, it is often underestimated or confused with cellulitis or abscess. Mortality rates are still high and have shown no tendency to decrease in the last 100 years. Unfortunately, the prevalence of the disease is such that physicians rarely become sufficiently confident with NF to be able to proceed with rapid diagnosis and management. This review covers the literature published in MEDLINE in the period 1970 to December 31, 2010. Particular attention is given to the clinical and laboratory elements to be considered for diagnosis. A wide variety of diagnostic tools have been described to facilitate and hasten the diagnosis of NF, but the most important tool for early diagnosis still remains a high index of clinical suspicion.

Angiographic study of the superior laryngeal artery

The study goals were to demonstrate the superior laryngeal artery in detail with angiograms and to understand its vasculature three-dimensionally. Three fresh cadavers were totally injected with lead oxide-gelatin mixture. The larynx with the surrounding tissue was resected and radiographed stereoscopically with soft X ray system. We get informed consent from a person in question and the bereaved family. The superior laryngeal artery was divided into the ascending and descending branches. The ascending branch supplied the epiglottis chiefly from the ventral surface, and anastomosed with branches of the lingual artery. The descending branch supplied the vestibular and vocal folds, muscles of the larynx and mucosa over the muscles, and anastomosed with distal branches of the superior thyroid artery. Stereographic angiograms and macroscopic observation enabled us to understand vasculature of the superior laryngeal artery.

Three-dimensional venous anatomy of the dermis observed using stereography

Veins of the dermis have been investigated mainly by histological methods in the fields of anatomy and histology, and a large number of schemata of the veins have been depicted in a variety of textbooks. However, the schemata are usually two-dimensional and it is therefore difficult to envisage the actual vasculature of the dermal veins. In this study, we performed a stereographic study of the skin of three fresh cadavers that had been injected with radio-opaque dye, which was dispersed throughout the entire body. A venous network consisting of venous polygons of various sizes existed just under the dermis or in the deep zone of the dermis, which is generally called the subdermal venous plexus. There were many small vessels towards the inside of each venous polygon, and most of them ascended, branching off stereoscopically. Those branches anastomosed with each other, and they formed the dermal and subpapillary venous plexuses. However, there was little vascular connection between dermal venous plexuses of different venous polygons. The characteristic structure of the dermal venous plexus has been considered to bring about venous congestion of the skin in various clinical situations.

Physiologically based pharmacokinetic modeling of arterial - antecubital vein concentration difference

BACKGROUND

Modeling of pharmacokinetic parameters and pharmacodynamic actions requires knowledge of the arterial blood concentration. In most cases, experimental measurements are only available for a peripheral vein (usually antecubital) whose concentration may differ significantly from both arterial and central vein concentration.

METHODS

A physiologically based pharmacokinetic (PBPK) model for the tissues drained by the antecubital vein (referred to as "arm") is developed. It is assumed that the "arm" is composed of tissues with identical properties (partition coefficient, blood flow/gm) as the whole body tissues plus a new "tissue" representing skin arteriovenous shunts. The antecubital vein concentration depends on the following parameters: the fraction of "arm" blood flow contributed by muscle, skin, adipose, connective tissue and arteriovenous shunts, and the flow per gram of the arteriovenous shunt. The value of these parameters was investigated using simultaneous experimental measurements of arterial and antecubital concentrations for eight solutes: ethanol, thiopental, 99Tcm-diethylene triamine pentaacetate (DTPA), ketamine, D2O, acetone, methylene chloride and toluene. A new procedure is described that can be used to determine the arterial concentration for an arbitrary solute by deconvolution of the antecubital concentration. These procedures are implemented in PKQuest, a general PBPK program that is freely distributed http://www.pkquest.com.

RESULTS

One set of "standard arm" parameters provides an adequate description of the arterial/antecubital vein concentration for ethanol, DTPA, thiopental and ketamine. A significantly different set of "arm" parameters was required to describe the data for D2O, acetone, methylene chloride and toluene - probably because the "arm" is in a different physiological state.

CONCLUSIONS

Using the set of "standard arm" parameters, the antecubital vein concentration can be used to determine the whole body PBPK model parameters for an arbitrary solute without any additional adjustable parameters. Also, the antecubital vein concentration can be used to estimate the arterial concentration for an arbitrary input for solutes for which no arterial concentration data is available.

Physiologically based pharmacokinetic modeling of arterial - antecubital vein concentration difference

BACKGROUND

Modeling of pharmacokinetic parameters and pharmacodynamic actions requires knowledge of the arterial blood concentration. In most cases, experimental measurements are only available for a peripheral vein (usually antecubital) whose concentration may differ significantly from both arterial and central vein concentration.

METHODS

A physiologically based pharmacokinetic (PBPK) model for the tissues drained by the antecubital vein (referred to as "arm") is developed. It is assumed that the "arm" is composed of tissues with identical properties (partition coefficient, blood flow/gm) as the whole body tissues plus a new "tissue" representing skin arteriovenous shunts. The antecubital vein concentration depends on the following parameters: the fraction of "arm" blood flow contributed by muscle, skin, adipose, connective tissue and arteriovenous shunts, and the flow per gram of the arteriovenous shunt. The value of these parameters was investigated using simultaneous experimental measurements of arterial and antecubital concentrations for eight solutes: ethanol, thiopental, 99Tcm-diethylene triamine pentaacetate (DTPA), ketamine, D2O, acetone, methylene chloride and toluene. A new procedure is described that can be used to determine the arterial concentration for an arbitrary solute by deconvolution of the antecubital concentration. These procedures are implemented in PKQuest, a general PBPK program that is freely distributed http://www.pkquest.com.

RESULTS

One set of "standard arm" parameters provides an adequate description of the arterial/antecubital vein concentration for ethanol, DTPA, thiopental and ketamine. A significantly different set of "arm" parameters was required to describe the data for D2O, acetone, methylene chloride and toluene - probably because the "arm" is in a different physiological state.

CONCLUSIONS

Using the set of "standard arm" parameters, the antecubital vein concentration can be used to determine the whole body PBPK model parameters for an arbitrary solute without any additional adjustable parameters. Also, the antecubital vein concentration can be used to estimate the arterial concentration for an arbitrary input for solutes for which no arterial concentration data is available.

Distally based radial forearm flap with preservation of the radial artery: anatomic, experimental, and clinical studies

In this article we report on the anatomical, experimental, and clinical investigations of the distally adipofascial pedicled radial forearm flap based on the small perforators around the radial styloid process. There are about 10 small perforators (0.3-0.5 mm in diameter) from the distal radial artery around the radial styloid process. The longitudinal chain-linked vascular plexuses (suprafascial, paraneural, and perivenous) formed by the forearm ascending and descending branches of septofasciocutaneous perforators meet and cross over with the transverse carpal vascular plexuses around the radial styloid region. Based on these directional-oriented plexuses, distally based adipofascial pedicled radial forearm fasciocutaneous and adipofascial flaps were designed and successfully applied in 34 clinical cases. The pivot point was located at 1-2 cm above the radial styloid. The skin island plus adipofascial pedicle measured between 9-18 cm in length, with the adipofascial pedicle 3-4 cm in width. The length-to-width ratio is 3-5:1. The venous drainage of this distally based flap was investigated anatomically and experimentally. The cephalic vein has no positive role for venous drainage in distally based flaps. The difference between distally based flaps and reverse-flow flaps, clinical selection of fasciocutaneous and adipofascial flaps, advantages and disadvantages, and technical tips for operative success are discussed.

Venous drainage architecture of the temporal and parietal regions: anatomy of the superficial temporal artery and vein

Anatomy of the superficial temporal artery and vein was analyzed with arteriograms, venograms, and arteriovenograms of fresh cadavers that had been injected with contrast medium. The superficial temporal artery always divided into two major branches: the frontal and parietal branches. However, the superficial temporal vein divided into one, two, or three major branches. The distribution area of the major branches of the superficial temporal vein was larger than that of major branches of the superficial temporal artery, and arteriovenograms clearly demonstrated that, except for its proximal portion, the superficial temporal vein was independent of the superficial temporal artery. The frontal and parietal branches of the superficial temporal artery had thin venae comitantes that originated from the proximal portion of the superficial temporal vein, and the venae comitantes gave off branches toward the skin and the underlying soft tissue. Branches to the skin anastomosed with a superficial venous network in the skin layer, which was formed by ramifications of the superficial temporal vein. The venous architecture of the temporal and parietal regions consisted of cutaneous veins and venae comitantes and was basically similar to that of the forearm and scapular region.

Soft tissue coverage options for dorsal foot wounds

The soft tissue of dorsum of the foot consists of a thin pliable surface that allows for significant excursion and tendon gliding. Reconstructive options must preserve these important functions and allow for reasonable contour so the patient may wear a shoe postoperatively. Special attention must be given to the mechanism of injury and overlying pathophysiology involved with each wound. Local flaps can provide adequate wound coverage in settings in which the vasculature and subcutaneous structures have been preserved. In wounds in which the regional vascularity is compromised or in which tendon and bone have been lost, a free-tissue transfer can provide for more substantial coverage. The multiple options available with free-tissue transfer allows for the possibility of composite tissue transfer, including vascularized bone or tendon, and the ability to create a sensate flap with excellent contour.

Anatomical study of the venous drainage architecture of the scapular skin and subcutaneous tissue

Venous anatomy of the skin and subcutaneous adipofascial tissue in the scapular region was examined in 14 specimens of 12 fresh cadavers that had been injected systemically with contrast medium. Three-dimensional analysis was performed by radiographing the specimens stereoscopically and splitting them into the skin and subcutaneous adipofascial tissue layers. From the architecture, most of the venous blood that had perfused the dermis was considered to pool in a polygonal venous network, located in the skin layer; to flow chiefly through some large communicating veins; and to enter the scapular, parascapular, or circumflex scapular veins. Most of the venous blood that had perfused the subcutaneous adipofascial tissue was considered to enter the scapular or parascapular veins directly.

Anatomical relationship between arteries and veins in the scapular region

Veins in the scapular region were investigated in five fresh cadavers, in which radiopaque materials were injected into both the arterial and the venous systems, to determine their locational relationship to the arteries. This radiographic technique is very useful for comparing veins and arteries. Many veins not accompanying arteries were observed, and veins in the skin and subcutaneous tissue were considered to consist of venae comitantes and non-venae-comitantes. The non-venae-comitantes formed a mainly polygonal venous network in the skin layer, and large communicating veins connected the venous network to the scapular or parascapular veins. These veins played a role in the drainage of venous blood that had perfused the dermis and, in this sense, they should be named cutaneous veins.