Medial Vessels Research Articles

Development and characterization of a porous micro-patterned scaffold for vascular tissue engineering applications

The fabrication of functional small diameter blood vessel analogs has implications in vascular disease treatment. Current 3D models of the medial vessel layer lack micron-scale topographical cues that have shown promise in vitro by recapitulating native vascular smooth muscle cell (VSMC) behavior. A major obstacle to fabricating 3D scaffolds is maintaining adequate nutrient diffusion to cells. We have developed and characterized porous micro-patterned poly-caprolactone (PCL) scaffolds using a novel technique that integrates soft lithography, melt molding and particulate leaching of polylactic-co-glycolic acid (PLGA) micro/nanoparticles. Scanning electron microscopy showed that PLGA-leached scaffolds have circular pores significantly smaller than the size scale of the grooved surface pattern (48 microm grooves; 5 microm deep; 12 microm spacing). Diffusion of media through PLGA-leached scaffolds was six-fold greater than through non-porous scaffolds, indicating successful introduction of through-pores into PCL by the PLGA leaching technique. VSMC alignment on micro-patterned PLGA-leached scaffolds was similar to that on micro-patterned non-porous scaffolds, indicating no loss in cellular organization on PLGA-leached scaffolds. In contrast, cells seeded on micro-patterned sodium bicarbonate-leached scaffolds remained un-aligned. The ability to micro-pattern cells on porous scaffolds may facilitate the transfer of micro-technology from simple 2D substrates to complex 3D architectures, allowing for tight control over cellular organization in fabricated tissues.

The contralateral pectoralis muscle flap: a valuable alternative to cover chest wall tissue defects

The blood supply of the pectoralis major muscle is provided by the thoracoacromial artery and by segmental branches of the lateral thoracic artery and the internal thoracic artery. To close defects in the area of head, neck or chest, pectoralis flaps are commonly used pedicled on their major vessel. As the segmental medial vessels are capable of supplying the entire muscle, the pectoralis flap can be detached from its clavicular and acromial origin. Its main vessel is ligated and the flap can be transposed to the opposite side of the thorax to close tissue defects due to breast cancer, radiodermatitis and infectious or traumatic loss of tissue.

Medial Plantar Artery (Instep Flap) Flap

Provision of sensation to the weightbearing surface of the heel is very vital in the sensate foot. Hence, resurfacing the weightbearing surface of the heel requires provision of stable skin cover and sensation. We have many options to fulfill the above requirements. Skin of the instep area can be raised as an island fasciocutaneous flap based on medial plantar vessels, with the branch of medial plantar nerve supplying the instep skin to provide the sensation. Medial plantar artery (instep) flap provides similar tissue with sensation and reaches the posteriormost part of the weightbearing surface of the heel with ease. We present in this article the relevant surgical anatomy, technique, and the clinical experience of 12 patients.

An Anatomic Study of the Cephalic Vein in the Deltopectoral Shoulder Approach

There has been debate regarding medial or lateral retraction of the cephalic vein in the deltopectoral approach to the shoulder. Those who recommend lateral retraction of the vein cite multiple feeder vessels from the deltoid muscle; however, there is little evidence to support this in the orthopaedic literature. The purpose of our study was to determine if there are more lateral branches than medial branches to the cephalic vein in the deltopectoral groove. Forty fresh frozen cadaveric shoulders underwent retrograde latex injection of the cephalic vein. A deltopectoral incision was used, and the numbers of medial and lateral branches were recorded. In the deltopectoral groove there were more lateral than medial feeder vessels to the cephalic vein. There also were more branches to the vein in the proximal (1/2) of the incision compared with the distal (1/2). Most of the specimens dissected had more lateral branches to the cephalic vein than medial branches. Based on the number of feeder vessels to the cephalic vein, results of our study support lateral retraction of the cephalic vein in a majority of shoulders during the deltopectoral approach to the shoulder.

Gastrocnemius muscle flap of both heads on a single vascular pedicle

We present a case of a muscle flap of both heads of gastrocnemius on a single vascular pedicle for reconstruction of a tibial defect. The flap was based on the medial sural vessels alone. The vascular supply to the lateral head was achieved through the anastomotic vessels along the gastrocnemial raphe.

Die Arterien des Humerus und deren Bedeutung für die Frakturbehandlung

The purpose of the current work was to study the arterial blood supply of the humerus to evaluate impairments of the blood supply after humeral fractures and different methods of fracture treatment. Arterial blood supply of the humerus was studied by corrosion injection technique in 6 cadaver preparations and is compared with the existing literature. Humeral head arteries originate from the circumflex humeral arteries. The major vessel enters the greater tubercle. Another group of vessels accesses the head from medially. The nutrient artery for the shaft enters into the medial third of the shaft. At the distal humerus there are multiple anastomoses with penetrating branches into both condyles and proximal to the radial, coronoid, and olecranon fossae. Fragments of a proximal humeral fracture usually have an independent blood supply. The medial vessels to the head gain high importance in fractures of the anatomical neck. The nutrient artery lies regularly medial to the humeral mid-shaft and is at risk at open reduction of this region. The abundant vessels at the entire distal humerus ensure sufficient vascularization of the fragments after fracture.

Ultrastructure of the Circulatory System of the Phoronid Phoronopsis harmeri Pixell, 1912. 2. Main vessels

The ultrastructure of the wall of the main blood vessels of the phoronid Phoronopsis harmeri is described. The walls of the lophophoral and left lateral vessels consist of myoepithelial cells of the coelomic lining (peritoneal cells), a thin basal lamina, and an incomplete endothelial lining. In the head region of the body, the wall of the medial vessel consists of myoepithelial cells of the coelomic lining (peritoneal cells), a basal lamina, and true muscular endothelial cells. The anterior part of the medial vessel functions as the heart. In the anterior part of the body, the medial vessel wall consists of five layers: the external nonmuscular coelothelium, a layer of the extracellular matrix, the internal muscular coelothelium, an internal layer of the extracellular matrix, and an incomplete endothelial lining. The complicated structure of the medial vessel wall may be explained by the superimposition of the lateral mesentery on the ordinary vessel wall.

An assessment of the anatomical basis of the thoracoacromial artery perforator flap

Musculocutaneous perforator flaps offer advantages over musculocutaneous flaps, including reduced donor site morbidity, more predictable reconstruction of soft tissue deformities, and a wider variety of flap options. Perforator flaps are becoming increasingly popular for many applications. In the present study, we set out to examine the various perforators of the thoracoacromial axis through the pectoralis major (PM) muscle with respect to their suitability for transfer to the head and neck region as a pedicled flap. A series of 10 fresh cadavers were injected with lead oxide, gelatin and water (250 mL/kg) through the femoral vessels. The cadavers were cooled and the integument was removed. Perforating vessels from the underlying muscles were marked and the resulting angiograms of the integument and deep tissues were compared with the dissection notes describing the course, size and distribution of the perforating vessels. THE PERFORATORS THROUGH THE PM MUSCLE TO THE OVERLYING SKIN INCLUDED THREE REGIONAL GROUPS: perforators of the thoracoacromial axis; perforators of the medial intercostal vessels; and perforators of the lateral thoracic artery. The major group of perforators supplying the overlying skin was from the intercostal vessels. However, the thoracoacromial axis did consistently give rise to perforators in the upper portion of the PM muscle. In particular, there were reliable perforators from the clavicular and deltoid branches of the thoracoacromial artery. The present study illustrates the potential clinical applications of a series of perforator flaps based on the thoracoacromial axis, which may be useful in head and neck reconstructive surgery.

The arterial supply of the lesser metatarsal heads: a vascular injection study in human cadavers.

The possibility of avascular changes of the metatarsal heads following forefoot surgery has been previously documented. The aim of this study was to investigate the arterial supply of the lesser metatarsal heads with regard to osteotomies of these bones. We used epoxy resin injections and a modified Spalteholz technique in human cadaveric specimens to demonstrate the intraosseous and extraosseous blood supply of the lesser metatarsals. The metatarsal heads had two arterial sources: 1. The dorsal metatarsal arteries, which arose from the dorsalis pedis artery, and 2. The plantar metatarsal arteries, which are branches of the posterior tibial artery. These two vessels typically anastomosed at two sites about the metatarsal heads, forming a vascular ring and provided an extensive extraosseous arterial network around the metatarsal heads. Small arterial branches of this network run distally on the metatarsal cortex to enter the bone of the metatarsal head. The nutrient arteries traversed the cortex of the metaphysis close to the capsular and ligamentous insertions to provide multiple branches for the supply of the subchondral bone. Extensive capsular stripping during metatarsal head osteotomies results in damage to the medial and lateral head vessels.

Effects of epidural anesthesia on microcirculatory blood flow in free medial saphenous fasciocutaneous flaps in dogs.

To assess the effects of epidural anesthesia using lidocaine on microcirculatory blood flow, volume, and velocity in free fasciocutaneous flaps in dogs. Study Design-In vivo experimental investigation. Animal Population-Ten adult dogs weighing 20 to 25 kg. A medial saphenous fasciocutaneous free flap was removed and an orthotopic transfer was performed by anastomosing the primary flap vessels back to the medial saphenous vessels. Blood flow (mL(LD)/min/100 g), volume (%volume or tissue hematocrit) and velocity (mm/s) in the flap were recorded throughout the procedure. After epidural anesthesia, blood flow, volume, and velocity values were again recorded. Microcirculatory blood flow, volume, and velocity, as measured by a laser-Doppler flowmeter, failed to reveal any significant changes over time. Immediately after epidural anesthesia, mean arterial pressure was significantly reduced and remained depressed throughout the experimental procedure. Epidural anesthesia combined with general anesthesia does not improve microcirculatory flow in free flaps in the pelvic limbs of dogs. No significant change in blood flow to the medial saphenous fasciocutaneous free flap occurred after division and anastomosis of the vascular pedicle. We recommend that epidural anesthesia with 2% lidocaine be used with caution in dogs undergoing microvascular free-flap transfer.

Free Medial Plantar Perforator Flaps for the Resurfacing of Finger and Foot Defects

In this article, three cases in which free medial plantar perforator flaps were successfully transferred for coverage of soft-tissue defects in the fingers and foot are described. This perforator flap has no fascial component and is nourished only by perforators of the medial plantar vessel and a cutaneous vein or with a small segment of the medial plantar vessel. The advantages of this flap are minimal donor-site morbidity, minimal damage to both the posterior tibial and medial plantar systems, no need for deep dissection, the ability to thin the flap by primary removal of excess fatty tissue, the use of a large cutaneous vein as a venous drainage system, a good color and texture match for finger pulp repair, short time for flap elevation, possible application as a flow-through flap, and a concealed donor scar.

Selection of the recipient vessel in the free flap around the knee: the superior medial genicular vessels and the descending genicular vessels.

In reconstructions around the knee, the use of a free flap is indicated in a limited number of cases, but it plays a critical role in cases of extensive defects or unavailability of local flaps. The selection of the recipient vessel is an essential and challenging step for a successful free tissue transfer. Popliteal vessels and other small vessels around the knee have been reported to be used as recipient vessels, but the choice of recipient vessels around the knee has not been established. In this study, after a thorough investigation of the vascular anatomy at the knee region, the superior medial genicular vessels and the descending genicular vessels were considered to be the proper recipient vessels, and a clinical application was tried. From July of 1997 to July of 1999, a total of seven cases of soft-tissue defects around the knee-four cases in the posterior region and three cases in the anterior region-were reconstructed with free flaps, using the superior medial genicular vessels and the descending genicular vessels, respectively. All flaps survived completely, with no flap loss. The advantages of these vessels are their proximity to the knee and their reliability, versatility, simplicity, and size match. The outstanding characteristic of this combination of vessels is their versatility, because the combination can cover all defects around the knee. The clinical application and the versatility of the combination of the superior medial genicular vessels and the descending genicular vessels as the recipient vessels was confirmed for the reconstruction of posterior and anterior knee defects.

The Morphology of the Phoronid Phoronopsis harmeri

We studied the morphology and gross anatomy of the phoronid Phoronopsis harmeriusing light microscopy and scanning electron microscopy. The body of Ph. harmeriis subdivided into several regions: a lophophore, a head, anterior, and posterior parts of the body, and an ampulla. The lophophore is spiral and comprises 0.5 turns. In males, there are lophophoral organs in the tentacular crown; under the lophophore, there is an epithelial fold or collar. The internal organization shows partitioning into three coeloms: the coelom of the epistome, the tentacular coelom, and the trunk coelom. The trunk coelom is divided into a series of chambers by a complex system of mesenteries. The intestine is U-shaped, and the epistome is located above the mouth opening. The circulatory system is closed and consists of the following vessels: the efferent and afferent “circular”, left and right lateral (efferent), and medial (afferent) vessels. In Ph. harmeri, there is a dorsolateral (afferent) vessel running through the ampulla and the lower part of the posterior trunk region. The excretory system is composed of paired metanephridia that resemble asymmetrical U-shaped tubes. Sexual dimorphism is characteristic of the structure of the distal part of the nephridium, which opens into the body cavity. The nervous system consists of a dorsal nervous field, a circular nerve plexus, and a giant left nerve fiber. Ph. harmeriis a dioecious species; the gametes develop in a vasoperitoneal tissue that envelops the intestine in the posterior part of the trunk region.

Immunohistochemical study of the phosphorylated and activated form of c-Jun NH2-terminal kinase in human aorta.

c-Jun NH2-terminal kinase is a key enzyme mediating the cellular response to a variety of extracellular stimuli. In the present study, we performed immunohistochemical studies of the expression of the phosphorylated form of the kinase in 51 human aortas of various ages. The phosphorylated kinase immunoreactivity was strongly detected in vascular smooth muscle cells of the medial vessel layer of atherosclerotic lesions from adults. Immunoreactivity was also strongly detected in similar cells of the intima. On the other hand, immunoreactive phosphorylated kinase was only weakly defected in the medial vascular smooth muscle cells of non-atherosclerotic lesions from adults. We also investigated the expression of the phosphorylated kinase in infant aortas. In contrast to its weak immunoreactivity in adult non-atherosclerotic lesions, the kinase immunoreactivity was detected in high amounts in vascular smooth muscle cells of non-atherosclerotic lesions from infants. Thus, the abundant expression of the phosphorylated kinase in these cells in atherosclerotic lesions of adults and non-atherosclerotic lesions of infants suggests that the activation of c-Jun NH2-terminal kinase may be an important element initiating the proliferation of vascular smooth muscle cells during atherogenesis and aortic development.

Arterial and lymphatic supply of the knee integuments.

The surgical approach to the anterior knee region carries a risk for postoperative integument infection and skin necrosis. A hypothesis is that surgical approach may damage integumental blood supply and additionally the lymphatic drainage from the foot and leg. The goal of this study was to describe the arteries and lymphatics directly affected by the antero-medial approach. Injection of the femoral a. was used to identify the femoral and popliteal aa. and their branches distributed to the integument of the anterior, medial and lateral aspects of the knee. Lymphatic injection into the plantar aspect of the first toe was also performed to identify the subdermal lymphatics traversing the area. Our results showed that most of the blood supply arises from the medial aspect of the knee integuments. However, subcutaneous arterial anastomoses provide a significant blood-supply when there is interruption of the medial vessels as seen in the medial surgical approach to the knee. Most of the lymphatic drainage originating from the foot crosses the knee region on the medial side, opposite or below the tibial tuberosity. Because the subdermal arterial network is well-developed, the medial approach for knee surgery does not endanger the anterior knee integuments as long as the lateral vascular supply is preserved. However, this approach may interrupt the lymphatic circulation, particularly in the case of an extended incision, which could explain postoperative edema and an increased rate of wound infection.

Long-term outcome after open reduction through an anteromedial approach for congenital dislocation of the hip.

We reviewed the long-term outcome of open reduction of ninety-three congenitally dislocated hips (in seventy-six children) through an anteromedial approach. The average age of the patients was fourteen months (range, two to fifty months) at the time of the reduction and eleven years (range, four to twenty-three years) at the time of the most recent follow-up evaluation. At the most recent follow-up evaluation, sixty-six hips (71 per cent) had an excellent or good result, twenty-four (26 per cent) had a fair result, and three (3 per cent) had a poor result, according to the Severin classification system. An inverted neolimbus at the time of the operation and postoperative growth disturbance of the femoral head were associated with a poor roentgenographic result. According to the classification of Bucholz and Ogden, twenty-two hips (24 per cent) had type-II avascular necrosis, thirteen hips (14 per cent) had type-III, three (3 per cent) had type-IV, two (2 per cent) had non-classifiable lesions, and fifty-three (57 per cent) did not have avascular necrosis. A high hip dislocation and an operation after the age of twenty-four months were associated with a higher rate of growth disturbances of the femoral head. With the numbers available for study, we did not find any association between short-term preoperative traction, ligation of the medial circumflex vessel, or the type of neolimbus and the prevalence of growth disturbances. Two hips redislocated postoperatively, and seven had transient stiffness. We consider the anteromedial approach to be useful in the management of patients with congenital dislocation of the hip who are twenty-four months old or less. The advantages of this approach include direct access to the obstacles to reduction, avoidance of damage of the iliac apophysis and the abductor muscles, minimum blood loss, the need for only a single operative session for treatment of both hips, and a cosmetically acceptable scar. The prevalence of type-II growth disturbances of the femoral head was higher than had been expected, emphasizing the need for additional investigation.

Medial saphenous fasciocutaneous and myocutaneous free flap transfer in eight dogs.

Skin defects on the distal extremity (n = 7) or face (n = 1) of eight dogs were repaired using a medial saphenous fasciocutaneous or myocutaneous flap. The cause of the wounds were ablative oncological surgery (n = 4), trauma (n = 3), or radiation burn (n = 1). The flap was removed from the medial femorotibial region, and transferred to the wound bed. The vascular supply to the flap was reestablished via microvascular anastomosis of the medial saphenous vessels of the flap to recipient vessels isolated adjacent to the wound. Three flaps incorporated the distal half of the caudal head of the sartorius muscle to form a myocutaneous free flap. All flaps survived completely. The medial saphenous fasciocutaneous and myocutaneous free flaps were found to be reliable and cosmetically acceptable for repair of skin defects in dogs.

Laparoscopic transillumination for the location of anterior abdominal wall blood vessels.

To determine the efficacy of transillumination for locating abdominal wall vessels prior to trocar placement during laparoscopy. Prospective clinical descriptive study. Normal human volunteers in an academic research environment. Forty-seven white and 21 black women of various weights undergoing laparoscopy for clinical indications unrelated to this study. None. The location and number of abdominal wall vessels visible by transillumination were recorded for each patient. In women of normal weight, a single vessel could be seen approximately 5 cm from the midline in > 90% of the patients, and second vessel approximately 8 cm from the midline could also be seen in 51%. The more medial vessels did not correlate with the course of the inferior epigastric vessels seen laparoscopically. The ability to see vessels was decreased significantly by the patients' weight but not by skin color. Superficial abdominal wall vessels may be located by transillumination in the majority of women of normal weight regardless of skin color, but is of less value in overweight and obese women. However, the deep (inferior) epigastric vessels cannot be effectively located by transillumination, and thus other techniques should be used to minimize the risk of injury to these vessels.

Injury of a Medial Sacral Vessel During Lumbar Laminectomy

Vascular injury sustained during neurosurgical procedures is surprisingly rare, especially considering the anatomic proximity of major blood vessels to the vertebral column. Mortality rates are high if the injury is not recognized and definitive management is delayed. Case reports include massive hemorrhage, arteriovenous fistulas, and development of false aneurysms. Diagnostic CT scan and arteriography are useful if the patient's condition permits; however, rapid intervention is crucial to the patient's survival. After reviewing the current surgical literature, we present a case of medial sacral artery injury occurring during laminectomy.

Internal fixation of calcaneus fractures: an anatomical study of structures at risk.

This study examines the risk of injury to medial soft-tissue structures during the fixation of calcaneal fractures performed through a lateral approach. An L-shaped lateral incision was performed on 10 fresh cadaver feet. The calcaneus was divided into three zones for study. Ten K-wires were inserted in a standard configuration from a lateral starting point extending through the medial cortex. The feet were dissected medially to measure the distance from each exiting K-wire to the medial and lateral plantar vessels, the calcaneal branch of the posterior tibial nerve, and the tendons of the flexor hallucis longus, flexor digitorum longus, and posterior tibialis. The mean risk of injury to these medial structures was calculated for each lateral insertion site. Wires placed in the subchondral bone of the posterior facet or anterior to the critical angle of Gissane were determined to be at high risk of injury to the medial soft tissues. Structures at risk included the medial and lateral plantar nerves and vessels and the flexor hallucis longus tendon. Caution should be exercised when inserting K-wires, drills, and screws into high-risk areas to avoid iatrogenic injury to the medial structures.