Arterial and venous anatomical features of the pectoralis minor muscle flap pedicle

The pectoralis minor muscle has been used as an innervated, vascularized, free-muscle graft in the field of facial reanimation for 20 years. Throughout this period, several centers have demonstrated consistent success with functional muscle transfer; however, opinions regarding the arterial pedicle of the flap have varied. The lateral thoracic and thoracoacromial arteries have been proposed as the predominant arterial sources. It has been the experience of our unit that a vessel (not described in anatomy textbooks) arising directly from the axillary artery and entering the muscle from its dorsal surface provides the dominant supply to the flap and is capable of sustaining it for free-tissue transfer. The vascular pedicle encountered was recorded and photographed in 97 consecutive cases in which the pectoralis minor muscle flap was raised. The findings demonstrated that the dominant supply to the muscle was from a single artery in 77 percent of cases and took the form of an artery arising directly from the axillary vessel in 72 percent of cases. More than one major arterial source was noted in the remainder of the cases. The venous outflow was usually through single or multiple veins running directly from the muscle into the axillary vein.     

The thoracoacromial vessels as recipient vessels in microsurgery and supermicrosurgery: an anatomical and sonographic study

The purpose of this study was to investigate the presence and the precise course of the pectoral branch of the thoracoacromial vessels on the underside of the pectoralis major muscle by anatomical dissection and by color Doppler ultrasound. A further goal was to determine whether these vessels were suitable as recipient vessels in microsurgery and supermicrosurgery for breast reconstruction. In 18 cadavers, the pectoral branch of the thoracoacromial vessels was followed caudally until the diameter of the artery diminished to 1 mm. The same examination was carried out in 40 young female volunteers by tracing the vessel course with color Doppler ultrasound. The 1-mm cutoff point of the artery was measured with reference to the manubrium, the midsternal line, the clavicle, and the upper border of the closest rib. In addition, in the cadavers, the 2-mm cutoff point was determined. At both cutoff points, the diameter of the accompanying vein was measured. The pectoral branch of the thoracoacromial vessels with the artery and concomitant veins could be detected on all 100 undersides of the pectoralis major muscle, anatomically and sonographically. In their course from the acromial region downward, the arteries reached a diameter of 1 mm at an average of 9.9 cm from the manubrium, horizontally 9.4 cm from the midsternal line, and vertically 4.0 cm from the lower border of the clavicle. The 1-mm reference point was situated on the upper border of the third rib in 85 percent of cases. The average distance between the 1-mm and the 2-mm cutoff points was 3.5 cm. At the 1-mm cutoff point, the diameter of the vein was 0.9 mm, and at the 2-mm cutoff point, it was 1.7 mm. Because of their central position at the anterior hemithorax, these vessels are easily accessible from mastectomy incisions, even in skin-sparing mastectomies; the donor-site morbidity is negligible; and as the diameters of the vessels gradually decrease along their caudal course, the recipient site can be chosen precisely according to the length and the diameter of the donor vessels and major mismatch can be avoided. Thus, the pectoral branches of the thoracoacromial vessels are well suited as recipient vessels for (super)microsurgery and are a very promising addendum to the thoracodorsal and internal mammary vessels.     

Arguments justifying the acception of the notion "sublobular artery" in the nomenclature of renal vessels: the "conical" architectonics of the renal cortex

The corrosion technique was used to demonstrate the presence of the "sublobular artery", a constant vessel with a special profile of the dog kidney, generating after two divisions the so-called interlobular arteries as a third generation of branches. More rarely arteriae interlobulares emerge also directly from the arcuate artery. The sublobular arteries (= parent vessels of the interlobular arteries) are characterized by their particular origin, branching type, and by having no or sporadically disposed glomeruli. For this reason, the authors suggest the acception of the term "arteria sublobularis" in the international nomenclature of renal vessels. According to authors' opinion the dog kidney is composed of a number of conical vascular-parenchymatous units, each containing in their axis a sublobular artery of the second order ("conical" architectonics of the renal cortex).     

Influence of tensile strain on smooth muscle cell orientation in rat blood vessels.

Blood vessels are subject to tensile stress and associated strain which may influence the structure and organization of smooth muscle cells (SMCs) during physiological development and pathological remodeling. This study focused on the influence of the major tensile strain on the SMC orientation in the blood vessel wall. Several blood vessels, including the aorta, the mesenteric artery and vein, and the jugular vein of the rat were used to observe the normal distribution of tensile strains and SMC orientation; and a vein graft model was used to observe the influence of altered strain direction on the SMC orientation. The circumferential and longitudinal strains in these blood vessels were measured by using a biomechanical technique, and the SMC orientation was examined by fluorescent microscopy at times of 10, 20, and 30 days. Results showed that the SMCs were mainly oriented in the circumferential direction of straight blood vessels with an average angle of approximately 85 deg between the SMC axis and the vessel axis in all observed cases. The SMC orientation coincided with the principal direction of the circumferential strain, a major tensile strain, in the blood vessel wall. In vein grafts, the major tensile strain direction changed from the circumferential to the longitudinal direction at observation times of 10, 20, and 30 days after graft surgery. This change was associated with a decrease in the angle between the axis of newly proliferated SMCs and that of the vessel at all observation times (43 +/- 11 deg, 42 +/- 10 deg, and 41 +/- 10 deg for days 10, 20, and 30, respectively), indicating a shift of the SMC orientation from the circumferential toward the longitudinal direction. These results suggested that the major tensile strain might play a role in the regulation of SMC orientation during the development of normal blood vessels as well as during remodeling of vein grafts.     

Anatomical basis for the clinical application of the arterial supply of musculus pectoralis major.

The pattern of arterial supply to the various parts (clavicular, sternocostal and aponeurotic) of the pectoralis major muscle was studied in 7 cadaver dissections and 10 angiograms by injecting a radio-opaque substance. Three main arteries supplied the muscle, i.e. the pectoral branch of the thoracoacromial trunk (TAT-PB), the lateral thoracic artery and the perorating branch of the internal thoracic artery, supported by other branches of the TAT and the superior thoracic artery. It is observed that the TAT-PB, a chief vascular pedicle, anastomoses freely with other arteries and supplies most parts of the muscle. The present study is mainly focussed on the exclusion of the chief vascular pedicle of muscle to eliminate the confusion of previous studies and prevent the unnecessary hindrance and complications of the muscle flap.     

Vertebral artery tortuosity with concomitant erosion of the foramen of the transverse process of the axis. Possible clinical implications.

Thirty-six vertebral arteries were examined for the presence of tortuosity in their trajectory through the neck. Of these, 18 vessels (14 bilateral) showed various degrees of tortuosity of their proximal segment. Four arteries had marked kinking of the tortuous vessel at the foramina of the transverse process of the axis. These foramina presented with marked erosion of the underlying bone. Four other axes presented with moderate erosion of the F/Tp. The etiology and clinical significance of tortuosity of the vertebral artery, and erosion of the F/Tp of the axes, are discussed in light of the extreme range of rotation occurring at the C1-C2 segmental level.     

The lateral pectoral composite flap in one-stage reconstruction of the irradiated mandible

We present a composite flap based on the musculature of the anterolateral thorax that allows immediate reconstruction of the mandible through the interposition of vascularized bony fifth rib. While the vascular pedicle remains the pectoral branch of the thoracoacromial artery, the pectoralis major muscle can be spared largely intact. The lateral position of the composite rib segment ensures a purely bony composition, while the lateral skin island remains largely hairless. Despite the unfavorable conditions of massive tumor size and prior irradiation attending the clinical cases presented, the complication rate was acceptable, with only one flap loss, and this followed technical error.     

Electron microscopy of histamine-induced contraction of the in vitro swine coronary artery.

Dose-dependent contractions of the in vitro swine coronary artery were induced by application of histamine and acetylcholine, but not of angiotensin II, ergonovine, noradrenaline, prostaglandin F2 alpha and serotonin. Ultrastructural changes especially of the tunica intima during the contractions were observed at 2, 5 and 30 min after application of histamine and acetylcholine. The intimal gutter spirally running along the longitudinal axis of the vessel was obscured, and the intimal surface became extensively indented. Exclusively in the histamine-treated samples, the increase in number and size of the intracellular vacuoles and the dilation of the intercellular clefts to the extent of the intercellular vacuoles were observed in the endothelium. Moreover, the enhancement of the endothelial permeability was indicated by the marker experiments using horseradish peroxidase. Such endothelial cell damages and the enhancement of the endothelial permeability may amplify the coronary artery contraction.     

Right Internal Mammary Artery Implantation into Right Ventricular Myocardium for Revascularization of the Entire Heart: Experimental Data and Preliminary Report

The left internal mammary artery implant combined with epicardiectomy and free omental graft provides three extra-coronary sources of blood. This operation tested in dogs with 92% main-stem occlusion of three coronary arteries protected 75% of the animals. Applied clinically in over 100 patients, the operation resulted in 90% improvement. To obtain complete myocardial revascularization, the right internal mammary artery has been used as a fourth source of extra-coronary blood. In 57 animals, the right internal mammary arteries were implanted into the anterior walls of the right ventricle; in 80% this vessel formed anastomoses with the right coronary tree, and in 65% with the right and left coronary arteriolar systems. Six patients are described who underwent right internal mammary artery implantation; five of these in addition had the combined operation of left internal mammary artery implant, epicardiectomy and free omental graft. All patients had completely blocked right coronary arteries; in addition, five had advanced disease of the left coronary arterial tree.     

Biaxial elastic material properties of porcine coronary media and adventitia

The importance of mechanical stresses and strains has become well recognized in vascular physiology and pathology. To compute the stress and strain on the various components of the vessel wall, we must know the constitutive equations for the different layers of the vessel wall. The objective of the present study is to determine the constitutive equation of the coronary artery treated as a two-layer composite: intima-media and adventitial layers. Twelve hearts were obtained from a local slaughterhouse, and the right coronary artery and left anterior descending artery were dissected free from the myocardium. The vessel wall was initially mechanically tested biaxially (inflation and axial extension) as a whole (intact wall) and subsequently as intima-media or adventitial layer. A Fung-type exponential strain energy function was used to curve fit the experimental data for the intact wall and individual layers for the right coronary artery and left anterior descending artery. Two methods were used for the determination of material constants, including the Marquardt-Levenberg nonlinear least squares method and the genetic algorithm method. Our results show that there were no statistically significant differences in the material constants obtained from the two methods and that either set of elastic constants results in good fit of the data. Furthermore, at an in vivo value of axial stretch ratio, we find that the stiffness is as follows: intima-media > intact > adventitia. These results underscore the composite nature of coronary arteries with different material properties in each layer. The present results are necessary for analysis of coronary artery mechanics and to provide a fundamental understanding of vessel physiology.     

Skin island flaps supplied by the vascular axis of the sensitive superficial nerves: anatomic study and clinical experience in the leg.

An anatomic study performed on 64 fresh injected legs has shown the role of the vascular axis that follows the superficial sensitive nerves in supplying the skin. Three nerves were studied: the saphenous nerve, the superficial peroneal nerve, and the sural nerve. Conclusions are the same for the three nerves: The vascular axis, which can be either a true artery or an interlacing network, ensures the vascularization of the nerves, gives off several cutaneous branches in the suprafascial course of the nerve, and anastomoses with the septocutaneous arteries issuing from a deep main vessel. The superficial nerves that course the leg can therefore be considered as vascular relays owing to their neurocutaneous arteries. The concept of a neuroskin island flap has been developed and applied to six clinical cases for coverage of some specific areas of the knee and of the lower part of the limb.     

Thoracodorsal vessels as recipient vessels for the free TRAM flap in delayed breast reconstruction.

The internal mammary vessels have been recommended as the first choice recipient vessels for delayed breast reconstruction with the free TRAM flap. This approach has avoided surgery in the previously operated axilla, has required a shorter pedicle length, and has allowed for more medial placement of the TRAM tissue. Frequency of nonusable axillary vessels has been reported at 11 percent, with a 6 percent incidence of flap loss in the delayed reconstructive setting. We reviewed our experience with the thoracodorsal vessels as recipient vessels in delayed free TRAM breast reconstruction to assess more accurately the adequacy of these potential recipient vessels. All patients undergoing delayed TRAM reconstruction were reviewed. Forty-seven of 300 consecutive TRAM procedures were for planned delayed free reconstruction. In seven of the patients (15 percent), the thoracodorsal vessels were found to be inadequate for free reconstruction. A supercharged pedicled TRAM was used for reconstruction in each of these seven patients. Average operating room time was 7 hours. Mean follow-up time was 38 months. Nineteen percent of all patients developed at least one complication. Twelve percent of free TRAM patients developed a complication, whereas 57 percent of supercharged patients developed a postoperative complication. The difference in complication rates was statistically significant. The thoracodorsal vessels have provided an adequate recipient vessel in 85 percent of delayed free TRAM reconstructions, comparable to previous reports. Pedicling and supercharging the flap, in those situations in which the thoracodorsal vessels were inadequate, were associated with an increased incidence of postoperative complications. This suggests that in the delayed reconstructive setting, higher-risk patients benefit from free reconstruction over supercharged reconstructions. A second recipient vessel should be used when the thoracodorsal vessels are inadequate for planned free TRAM reconstruction. In these circumstances, we would recommend the use of the internal mammary vessels followed by the thoracoacromial vessels as reliable alternative recipient sites for delayed free TRAM reconstruction.     

Water Flow Through Vessel Perforation Plates--The Effects of Plate Angle and Thickness for Liriodendron tulipifera

The effects of scalariform perforation plate thickness and anglewithin vessel elements of Liriodendron tulipifera were studiedwith a computational fluid dynamical model. The pressure gradientand hence resistance to flow through the plate increased asthe perforation plate increased in thickness. Increasing theangle of the plate relative to the axis of the vessel (samenumber of pores) also increased the pressure gradient alongthe modelled cell. For the model matching the actual vesselelement, the plate contributed 8% to the flow resistance ofthe vessel element. This contribution increased only to 11%for doubled plate thickness, and to 14% for a plate at an angleof 60° to the vessel axis. The perforation plate alteredthe velocity profile across the vessel element, but to a differentextent depending on the angle of the plate. A plate at an acuteangle to the vessel axis has little effect on the paraboloidprofile as found upstream from the plate, while obtuse angleplates change the flow profile such that fluid through poresnear the wall is accelerated to a greater velocity than foundin the centre of the cell. Key words: Conductance, perforation plate, vessel, water flow     

Analytical solutions for the specific activities of a traced substance within the component parts of a simulated kidney-ureter system

Two models for a kidney-ureter system are considered: one model of one vessel in which a traced substance, undergoing exchange between the vessel and an external compartment, is emptying into the ureter; the second model of two approximately parallel, identical vessels in which a traced substance, undergoing exchange between each vessel and an external compartment, is emptying into the ureter. A single impulsive input of label into a vessel is assumed. For mathematical simplicity, the major conditions imposed on each system are: (1) rapid mixing transverse to a vessel axis and no mixing longitudinal to a vessel axis within the plasma; (2) small variation of the specific activity within the plasma in the longitudinal direction to a vessel axis; (3) constant flow rate of urine into the ureter and (4) constant exchange coefficients, tubule flow velocity and traced substance concentrations within individual compartments.     

Restenosis following percutaneous transluminal angioplasty: clinical,physiologic and pathological features.

Percutaneous transluminal coronary angioplasty (PTCA) has been used clinically for 8 years and is becoming widely accepted in the treatment of atherosclerotic coronary artery disease. Since the long-term effects of the procedure are unknown, the rate of restenosis following the procedure, approximately 30%, is of major concern. We briefly review the current status of PTCA and the effect of angioplasty on the vessel wall and discuss proposed mechanisms of recurrent stenosis.     

Abdominal part artery of axillary artery: proposed term for the artery supplying the abdominal part of the musculus pectoralis major.

In 1976, the authors reported that the abdominal part artery (Pab) supplying the abdominal part of the pectoralis major muscle usually originates from the axillary artery (Ax). The findings in the present study show that the type of origin of this artery most frequently encountered is type 2-a (44.0%) in which the Pab, as an independent branch (type a), branches out of the second part of the Ax (type 2). The second and third most frequently encountered types are type 2-b (17.0%), where the Pab has a common trunk with the thoracoacromial artery, and type 2-c (10.0%), where it has a common trunk with the lateral thoracic artery. By classification according to the supplying areas, 67% was type I-B, supplying the lower part of the pectoralis minor muscle and the abdominal part of the muscle. In 5%, the branch as type I-A courses down to the sternocostal part. In most cases (types A and B in 91%), this artery originates from the Ax proximal to the ansa mediana of the brachial plexus; however, in 4% providing the superficial brachial artery, the Pab branches out from the superficial brachial artery. Based on those findings, the authors would propose that the artery be named the arteria partis abdominalis or Pab.     

Vascularization of the myocutaneous latissimus dorsi flap. Injection study on the thoracodorsal artery

This study reports on investigations of the thoracodorsal artery by injection studies. This artery has a long proximal extramuscular course before it enters the muscle. A consistent neurovascular hilum was found at a considerably constant location on the inferior muscle surface, 2-3 cm medial to its lateral edge and about 5 cm distal to the inferior scapular border. A constant branching pattern of the thoracodorsal artery into a lateral and a medial vessel stem was found. A high number of muscle-perforating arteries from a dense network in the cutaneous and subcutaneous layer. The thoracodorsal artery supplies the whole cutaneous area adjacent to the latissimus dorsi muscle plus a streak of about 2 cm at the medial and distal muscle borders. The presented anatomical landmarks are useful for locating the neurovascular hilum, and the intramuscular course of the thoracodorsal artery for exploration of the vessel by Doppler sonography or dissection. The length of the pedicle and the relatively big vessel gauge are good anatomical markers for the free transfer of a latissimus dorsi flap.     

Natural history of coronary artery disease in relation to angiographic, hemodynamic and clinical factors

Studying the natural history of coronary artery disease could provide a frame of reference for prognosis and appraisal of treatment for patients having this disease. We studied a total of 465 consecutive patients with angiographically significant coronary artery disease, defined as greater than 50% stenosis in at least one principal artery, who were followed with medical treatment only from 1 to 7 years. Excluding patients with left main coronary disease, there were 73 deaths, of whom 63 were cardiac. The 5-year cumulative survival rates were 72% for the entire group, 87% for single vessel disease, 73% for double vessel disease and 51% for triple vessel disease. In single vessel disease, patients with left anterior descending artery involvement tended to have higher mortality. In double vessel disease, survival was worse with the combination of left anterior descending and right coronary artery involvements than the other 2 combinations. A history of myocardial infarction was not significantly different from angina in 5-year survival rate. Nevertheless, an abnormal Q-wave in ECG was associated with lower survival. History of hypertension and electrocardiographic left ventricular hypertrophy did not affect survival. While congestive heart failure, abnormal resting LVEDP and left ventricular asynergy were all associated with reduced survival. The left ventricular ejection fraction had highly prognostic value, only 42% of patients survived with ejection fraction less than 0.3 at the end of 5 years after angiography.     

Wood anatomy reflects the distribution of Krascheninnikovia ceratoides (Chenopodiaceae)

Wood anatomy characters of the Eurasian/North American half-shrub Krascheninnikovia ceratoides were investigated on plants from different parts of the wide distribution area. The secondary xylem is developed as result of anomalous secondary thickening. The vessels are small (commonly <50 μm) and the secondary xylem is rayless. Differences in vessel diameter exist between the main axis, basal branches and flowering shoots. The maximum as well as the minimum vessel diameter in the flowering shoots is significantly smaller compared to the basal branches, as well as in the main axis in all provenances. The length of thick-walled libriform fibre cells varies between the main axis and the basal branches of the same plant individual, but in the short main axis the length of libriform fibre cells is relatively constant (193-217 μm), independent of provenance and climate. Obviously, the length of libriform fibre cells is a conservative character and dependent on plant size. The vessel diameter is a more sensitive parameter for ecological studies. It varies more clearly, considering the vessel position in the plant axis system, in relation with climate differences of the provenances of the examined plants.Plants from a temperate, semi-humid climate have the largest vessel diameter in basal branches and flowering shoots, while the vessel diameter of plants from an arid temperate climate in Central Asia is smallest. The vessel diameters depend not only on climate, but also on the position in the axial system of the plants. There is a trade-off between average vessel number and their maximum diameter in flowering shoots of populations from Russia and Mongolia. Thus, vessel diameters depend on both, position in the axial system of the plant and climatic conditions.     

The pure posterior pedicle procedure for breast reduction

The inferior pedicle technique, which has already become classic, employs a glandular areola-bearing pedicle whose source of vascularization is primarily posterior. In fact, the inferior pedicle is a posterior pedicle with an inferior border. After systematically and progressively reducing this inferior border, I have completely eliminated it. The pure posterior pedicle that results is independent of the inframammary fold. It is vascularized by means of the pectoral muscle and fascia, as has been demonstrated by injection studies of the thoracoacromial artery in fresh cadavers. The resulting mammary reduction technique retains the advantages of the inferior pedicle technique while avoiding its major inconveniences: dependence on the inframammary fold, bulging at the inferior base of the pedicle, and the necessity of low positioning for the breast.