The angiosomes of the mammals and other vertebrates.

This is a comparative study of the vasculature of the integument and underlying deep tissues of a range of mammals and other vertebrates. The investigation was conducted in the pig, monkey, dog, cat, possum, guinea pig, rat, rabbit, duck, and toad. The results from each are compared not only to each other, but also to previously performed human studies. The arterial network of the fresh animal cadaver was injected with a mixture of lead oxide and gelatin. The vascular anatomy of the skin, deep tissues, and individual muscles was defined by dissection, cutaneous perforator counts, photography, and radiography. A similar pilot study of the venous framework was performed in the pig, dog, and rabbit that included maps of the sites and orientations of the valves. The vasculature of the integument and deep tissues was correlated, and we found that we were able to define angiosomes (composite blocks of tissue supplied by the same source vessel) in each animal. Results revealed a marked dissimilarity of the overlying cutaneous vessels in many cases, yet a striking resemblance of the vascular architecture of the deep tissues. The size and density of the cutaneous perforators bore a close relation to the degree of the skin mobility, being large and sparse where the skin was mobile and smaller and more densely grouped where the integument was tethered or fixed. The cutaneous vasculature of the human resembled that of the monkey closely, was similar to that of the dog, cat, and possum, and was dissimilar to that of the pig, rat, guinea pig, and rabbit. Studies of the amphibian and bird bore many resemblances to those of the mammals. They provided basic concepts regarding modification of the animals' vascular anatomy in response to the functional demands of the species. In each animal, the arteries formed an unbroken network throughout the body. This consisted of anatomic territories linked by anastomotic vessels that were usually of reduced caliber. The pattern of the venous system was almost identical. Valved venous territories were linked by avalvular (oscillating) veins. The common denominator in the vascular system is the capillary bed. Conceptually, the anatomic arrangement of the arteries and veins, reproduced in each species, appears to be a sophisticated mechanism to allow equilibration of flow and pressure arriving at and departing from the capillary bed. The angiosome concept is reinforced by the animal studies. Although this investigation is essentially a detailed pilot study, it embraces many animals commonly used for experimentation and provides a reference atlas of their vasculature.(ABSTRACT TRUNCATED AT 400 WORDS)     

Vascular anatomy of the anterolateral thigh flap

Arterial and venous anatomy and their relation to the anterolateral thigh flap were examined in 10 specimens of six fresh cadavers in which radiopaque materials were injected into both the arterial and venous systems. Territories and positions of individual perforating arteries were measured, and the venous drainage pathway of the flap was analyzed. All specimens were radiographed stereoscopically to observe the three-dimensional structure of the arteries and veins. The territory of each perforating artery was smaller than expected. Most of the venous blood that had perfused the dermis was considered to pool in a polygonal venous network located in the skin layer and to enter the descending branch of the lateral circumflex femoral artery through large descending veins. The venous territories were considered different from the arterial territories. The findings in this study suggest that the design of the anterolateral thigh flap should be based on the venous architecture rather than on the arterial architecture and that the flap survival rate might be improved if thinning is performed appropriately.     

The angiosomes of the head and neck: anatomic study and clinical applications

The angiosome concept was introduced over a decade ago by Taylor and Palmer, whereby the body was considered to be composed anatomically of multiple three-dimensional composite blocks of tissue supplied by particular source arteries. Since then, detailed studies of the forearm and leg have been examined by Taylor and his coworkers. This study focuses on another region--the head and neck. Six fresh head and neck cadaver specimens were examined after infusion with a radio-opaque lead oxide mixture and correlated with over 24 previous body studies. The vascular anatomy of the skin, superficial musculoaponeurotic system (SMAS), muscles, brain, dura, and bone was examined. Each layer was painstakingly removed, photographed, labeled, and mapped to the respective arteries and veins. A radiologic subtraction technique was used to allow successive layers to be compared. This information was then scanned into a computer, analyzed, color coded, and labeled, thereby producing a three-dimensional study of the head and neck region to identify the respective angiosomes. As in previous detailed examinations of the leg and forearm, the angiosomes were found to be connected usually within tissues, such as muscle, skin, specialized organs or glands, rather than between the tissues. The muscles usually had vessels of two or more angiosomes supplying them and fell into three major groups based on the similarity of their arterial supply. In some areas, the midline anastomoses were rich, especially in the integument of the scalp, forehead, and lips. In other regions, the midline vascular connections were poor, especially in the tongue and palate. No fewer than 13 angiosomes of the head and neck, supplied by the branches of the external carotid, internal carotid, and subclavian arteries, have been defined, mapping their three-dimensional territories in the skin, the deep soft tissues, and the bones. Although most angiosomes spanned between skin and bone, three territories, those of the vertebral, lingual, and ascending pharyngeal vessels, were confined to the deep tissues without cutaneous representation. Finally, this study provides additional data for the surgeon to help plan safer incisions and better reconstructive flap procedures. It also gives information that may help explain the etiology and treatment of head and neck arteriovenous vascular malformations.     

Anatomical consideration of reverse-flow island flap transfers from the midpalm for finger reconstruction.

Primary soft-tissue coverage for large palmar defects of the fingers is a difficult problem for cases in which homodigital or heterodigital flaps cannot be used. The aim of this study was to explore the vascular and neural anatomy of the midpalmar area to assess the possibility of reverse island flaps from this area. In 24 cadaver hands perfused with a silicone compound, the arterial pattern of the superficial palmar arch and common palmar digital artery was examined. The cutaneous perforating arteries and nerve branches supplying the midpalmar area were dissected, and the number, location, and arterial diameter of these branches were measured. In six other specimens, the common palmar digital artery was injected to determine the skin territory supplied by the artery. The superficial palmar arch contained the three common palmar digital arteries and its terminal branch coursed along the radial margin of the index metacarpus. This terminal branch had three to six cutaneous perforators (diameter range, 0.1 to 0.5 mm) and supplied the radial aspect of the midpalmar area located over the ulnar half of the adductor pollicis muscles. The midpalmar area was divided into two regions-the proximal and distal-according to the vascular distributions. The proximal region contained dense aponeurosis and thin subcutaneous tissue, and the cutaneous perforators were rather sparse (between three and nine) and had a small diameter (0.1 to 0.3 mm). The distal region, which had loose aponeurosis and abundant subcutaneous tissue, had a rich vascular supply from the common and proper digital artery. Perforating arteries of this region coursed frequently in an oblique fashion and the number of perforators (between eight and 15) and their arterial diameters (diameter range, 0.1 to 0.5 mm) were higher than those of the proximal region. The area of skin perfused by the common palmar digital artery was 5 x 3 cm at the distal midpalmar region. There were three to five cutaneous nerve branches from the palmar digital nerve supplying the midpalmar area. From this study, two different reverse flaps were proposed. First, a 5 x 2 cm flap from the distal midpalmar region was elevated on the basis of the common and proper palmar digital artery. Measurement of the rotation arc revealed that the pivot point of this flap was located at the proximal interphalangeal joint level and could cover the finger pulp of the digits. The second flap candidate was that from the radial aspect of the midpalm, which was supplied by the terminal branch of the superficial palmar arch. In studies with cadaver hands, connection of this artery with the deep arterial system enabled this flap to reach the thumb pulp. These flaps may be a useful reconstruction option for significant palmar soft-tissue loss of the fingers.     

Ex vivo intraoperative angiography for rectus abdominis musculocutaneous free flaps

In this study, the vascular architecture of rectus abdominis free flaps nourished by deep inferior epigastric vessels was investigated using an ex vivo intraoperative angiogram. Oblique rectus abdominis free flaps were elevated and isolated from the donor site. In 11 patients, the vascular architecture of these flaps was analyzed before the flap was thinned. Radiographic study identified an average of 2.1 large deep inferior epigastric arterial perforators in each flap. In nine of the 11 flaps, the axial artery was visible. In four flaps, the axial artery originated from the perforator of the lateral branch of the deep inferior epigastric artery; in five others, it originated from the medial branch. In each flap, the angle of the axial perforator from its anterior rectus sheath in the vertical plane was measured; its mean was 50.6 degrees. All flaps survived, although three showed partial necrosis in the distal portions. In two of these three flaps, the axial artery was not visible in the angiograms, and the third revealed a one-sided distribution of axial flap arteries. Using ex vivo intraoperative angiography, the architecture of the individual flap, its axial perforator, and its connecting axial flap vessel could be investigated. This information can help the surgeon safely thin and separate the flap.     

Comparison of three different supercharging procedures in a rat skin flap model

A significant clinical problem in reconstructive surgery is partial loss of a pedicled flap. To resolve this problem, various methods of vascular augmentation have been developed; "supercharging" is one of those techniques. A new rat flap model was developed for investigation of the supercharging procedure, and the efficacy of the arterial supercharging method was examined. The purpose of this study was to investigate how an arterial supercharging procedure could generate large flap survival areas with different supercharging positions in rats. On the basis of the vascular anatomical features of rats, a circumferential skin flap from the lower abdomen to the back, measuring 4 x 12 cm, was marked. The flap was divided along the dorsal midline. Forty rats were divided into four experimental groups, as follows: group 1 (control), flaps based only on the deep circumflex iliac artery and vein; group 2, flaps supercharged with the ipsilateral superficial inferior epigastric artery; group 3, flaps supercharged with the contralateral superficial inferior epigastric artery; group 4, flaps supercharged with the contralateral deep circumflex iliac artery. On the fourth postoperative day, the flaps were evaluated with measurements of necrosis and survival areas. Microfil (Flow Tech, Inc., Carver, Mass.) was then injected manually throughout the body, and the vascular changes produced by supercharging were angiographically evaluated. Compared with group 1 (control), the flap survival areas were significantly greater in distally supercharged flaps in groups 3 and 4 (mean flap survival, 91.2 +/- 5.2 percent and 90.5 +/- 10.6 percent, respectively; p < 0.001) and in proximally supercharged flaps in group 2 (45.9 +/- 4.1 percent, p < 0.05). Angiographic assessment of the flaps that survived completely revealed marked dilation of the choke veins among the territories and reorientation of dilated veins along the axes of the flaps. This study suggests that distal arterial supercharging (contralateral superficial inferior epigastric artery or contralateral deep circumflex iliac artery) is more effective than proximal arterial supercharging (ipsilateral superficial inferior epigastric artery) in increasing flap survival. Although the rat skin flap may not be analogous to human flaps, distal arterial supercharging might have useful therapeutic potential in increasing flap survival in clinical practice.     

Effect of arteriovenous flow reversal on blood flow and metabolism in a skin flap

Twelve pig buttock island flaps (10 X 10 cm) were studied for 6 hours after arteriovenous flow reversal at the level of the pedicle. Follow-up was 48 hours. Blood pressure, Po2, pH, and lactate were measured in flap arteries and veins. Oxygen consumption was calculated. Data indicated true flow reversal. Blood pressure and Po2 in flap veins increased to systemic arterial levels. Outflow was provided by the arterial system, demonstrating venous pressure and Po2 values. Lactate increased significantly (1.8 +/- 0.5 to 4.0 +/- 2.3 mmol/liter), while pH dropped from 7.43 +/- 0.03 to 7.11 +/- 0.02. Oxygen consumption remained below baseline. In four flaps thrombosis occurred within 6 hours; no flap survived 48 hours. The results of this study do not encourage clinical application of the concept of flow reversal.     

The vascular territories of the superior epigastric and the deep inferior epigastric systems

The vascular territories of the superior and the deep inferior epigastric arteries were investigated by dye injection, dissection, and barium radiographic studies. By these means it was established that the deep inferior epigastric artery was more significant than the superior epigastric artery in supplying the skin of the anterior abdominal wall. Segmental branches of the deep epigastric system pass upward and outward into the neurovascular plane of the lateral abdominal wall, where they anastomose with the terminal branches of the lower six intercostal arteries and the ascending branch of the deep circumflex iliac artery. The anastomoses consist of multiple narrow "choke" vessels. Similar connections are seen between the superior and the deep inferior epigastric arteries within the rectus abdominis muscle well above the level of the umbilicus. Many perforating arteries emerge through the anterior rectus sheath, but the highest concentration of major perforators is in the paraumbilical area. These vessels are terminal branches of the deep inferior epigastric artery. They feed into a subcutaneous vascular network that radiates from the umbilicus like the spokes of a wheel. Once again, choke connections exist with adjacent territories: inferiorly with the superficial inferior epigastric artery, inferolaterally with the superficial circumflex iliac artery, and superiorly with the superficial superior epigastric artery. The dominant connections, however, are superolaterally with the lateral cutaneous branches of the intercostal arteries. For breast reconstruction, it would appear that prior ligation of the deep inferior epigastric artery would be of advantage when elevating the lower abdominal skin on a superiorly based rectus abdominis musculocutaneous flap. The vascularity of this flap would be further increased by positioning some part of the skin paddle over the dense pack of large paraumbilical perforators. Based on these anatomic studies, the relative merits of the superior and deep inferior epigastric arteries with respect to local and distant tissue transfer using various elements of the abdominal wall are discussed in detail.     

A microdissected thin tensor fasciae latae perforator flap.

A new method, named "microdissection," has been introduced to create a thin flap by elevating the tensor fasciae latae perforator flap to serve as microdissected thin tensor fasciae latae perforator flap. In microdissection, perforators that run in the posterolateral direction in the adipose tissue after penetrating the deep fascia are dissected meticulously using an operative microscope, and a thin flap is elevated in a single process. The caliber of the perforator artery and vein in the tensor fasciae latae muscle measures approximately 0.7 mm and 0.9 mm, respectively. When transplanting the flap, an end-to-side anastomosis to the main artery measuring 1 to 2 mm is preferable to avoid the risk of arterial thrombosis. In contrast, an end-to-end anastomosis of the perforator vein to the comitans vein of the main artery can be performed safely. In the present study, 11 flaps were transplanted to the sites of skin defects of the neck, hand, axilla, knee, and foot. The author considers that the first clinical indication of this flap is reconstruction of hand skin defects.     

The osteocutaneous free fibula flap: is the skin paddle reliable?

This clinical and anatomic study was undertaken to see if the skin paddle of the osteocutaneous fibula flap could be made more reliable. Eighty cadaver limbs were dissected to evaluate the type, number, and location of the cutaneous perforators supplying the lateral leg. Three types of perforators were identified: septocutaneous, musculocutaneous, and a type we termed septomuscular, which does not actually run within the muscle substance but is adherent to the muscle. Although not a true musculocutaneous perforator, it should be treated as such clinically. Musculocutaneous perforators were found to be more numerous and more proximal than the septocutaneous perforators. Eighteen clinical cases demonstrate a 33 percent skin paddle survival when dissected as a septocutaneous flap and a 93 percent skin paddle survival when dissected as a septomusculocutaneous flap. In using the osteocutaneous fibula flap, it is recommended that a cuff of soleus and flexor hallucis longus be incorporated into the flap to help ensure flap viability.     

Angiosomes of the brachial plexus: an anatomical study

This anatomical study analyzed the neurovascular relationships of the brachial plexus. Ten fresh cadaveric brachial plexuses were examined after injection of the arterial system. The vascular anatomical features of the brachial plexus were documented with microdissection after lead oxide/gelatin injection. The specimens were analyzed by using radiography (including digital subtraction techniques) and light-microscopic, macroscopic, and digital photography. Four angiosomes, based on the subclavian, axillary, vertebral, and dorsal scapular arteries, were observed. As noted in previous angiosome studies, connections between angiosome territories lay within tissues, in this case, nerve trunks. Nutrient vessels penetrated nerve trunks at points of branching within the brachial plexus, with a Y-shaped mode of division on entry. The vascular supply was markedly rich, often with true anastomotic connections occurring within the nerves. There was much variation in supply, depending on the vascular anatomical features of the subclavian artery.     

Neurovascular territories of the external and internal oblique muscles

The purpose of this study was to document the extent of the arteries supplying the external and internal oblique muscles and the connections among the vascular territories. Ten adult human cadavers underwent whole-body arterial perfusion (200 ml/kg) with a mixture of lead oxide, gelatin, and water, through the carotid artery. The external and internal oblique muscles were dissected and subjected to radiography. The vasculature of each muscle was analyzed by using the paper template technique. The areas of the vascular territories of the individual intercostal arteries within the external oblique muscle varied from 9 to 22 percent. The area of the vascular territory of the muscular branch of the deep circumflex iliac artery was 5 to 18 percent. The ascending branch of the deep circumflex iliac artery supplied a mean of 35.7 percent of the vascular territory of the internal oblique muscle. The lower six posterior intercostal arteries supplied a mean of 48.5 percent. The lateral branches of the deep inferior epigastric artery supplied a mean of 15.8 percent. This information provides the basis for the design of external and internal oblique muscle flaps for functional muscle transfer.     

A 10-year retrospective review of 758 DIEP flaps for breast reconstruction

This study examined 758 deep inferior epigastric perforator flaps for breast reconstruction, with respect to risk factors and associated complications. Risk factors that demonstrated significant association with any breast or abdominal complication included smoking (p = 0.0000), postreconstruction radiotherapy (p = 0.0000), and hypertension (p = 0.0370). Ninety-eight flaps (12.9 percent) developed fat necrosis. Associated risk factors were smoking (p = 0.0226) and postreconstruction radiotherapy (p = 0.0000). Interestingly, as the number of perforators increased, so did the incidence of fat necrosis. There were only 19 cases (2.5 percent) of partial flap loss and four cases (0.5 percent) of total flap loss. Patients with 45 flaps (5.9 percent) were returned to the operating room before the second-stage procedure. Patients with 29 flaps (3.8 percent) were returned to the operating room because of venous congestion. Venous congestion and any complication were observed to be statistically unrelated to the number of venous anastomoses. Overall, postoperative abdominal hernia or bulge occurred after only five reconstructions (0.7 percent). Complication rates in this large series were comparable to those in retrospective reviews of pedicle and free transverse rectus abdominis musculocutaneous flaps. Previous studies of the free transverse rectus abdominis musculocutaneous flap described breast complication rates ranging from 8 to 13 percent and abdominal complication rates ranging from 0 to 82 percent. It was noted that, with experience in microsurgical techniques and perforator selection, the deep inferior epigastric perforator flap offers distinct advantages to patients, in terms of decreased donor-site morbidity and shorter recovery periods. Mastery of this flap provides reconstructive surgeons with more extensive options for the treatment of postmastectomy patients.     

Skin recycling following neovascularization using the rat musculocutaneous flap model.

The recycling of a skin territory as part of a musculocutaneous flap despite prior division of existing musculocutaneous perforators or vice versa within an axial cutaneous flap using skin from a previous musculocutaneous flap may sometimes be done safely if an adequate time period has been allotted to permit sufficient neovascularization from adjacent tissues. In order to test this clinically observed phenomenon, a musculocutaneous flap model based on perforators from the rat rectus abdominis muscle was developed and observed to have complete reliability. Groups of five Sprague-Dawley rats each were sequentially utilized to prove that by a single week following creation of a rectus abdominis musculocutaneous flap adequate peripheral neovascularization would evolve to permit total viability of secondary axial epigastric cutaneous flaps incorporating the same skin that initially was the cutaneous portion of the muscle flap. The converse was also confirmed possible, again using sequential groups of five rats each, in that by 2 weeks the skin of an initial abdominal cutaneous flap could instead be safely transposed and nourished as part of a rectus abdominis musculocutaneous flap. The proposition concerning the reliable reuse of identical skin territories as part of disparate metachronous flap configurations appears to be valid.     

新型小鼠跨区供血耳瓣模型的构建

目的：建立一个实时活体观察血管形态学变化小鼠跨区供血耳瓣模型。方法体重25～30 g清洁级ICR小鼠30只,双耳脱毛后,观察其血管分布情况。小鼠麻醉后,用眼科剪从尾侧向头侧剪断鼠耳基底部尾侧2/3,保留头侧1/3,形成耳前血管蒂跨三个血管体、二个choke区的耳瓣模型。将小鼠侧卧置于二维图像采集系统的动物承载台上,调节体视显微镜物镜并固定为25倍,设置步进参数,“弓”型路线渐次、局部采集造模后0,1,2,3,5,7,10,14,21,30 d的时间点图像,合成鼠耳全景图。重点观察皮瓣的坏死率、皮瓣内choke血管的形态学变化。结果 ICR小鼠耳有三个恒定的血管体来供养,从内到外依次为头侧血管体、中间血管体及尾侧血管体。术后5 d,耳瓣坏死面积趋于稳定,坏死率为（15±7）％。内侧血管体与中间血管体之间的choke动静脉的管径出现快速扩增,两者都在第10天左右达最大,choke静脉管径最高峰可达到原来的（3.9±0.5）倍,choke动脉管径最高峰可达到原来的（3.5±0.7）倍。10 d后,choke静脉管径开始减小,21 d后逐渐平稳,而choke动脉管径于术后10 d左右开始平稳,之后无明显减小。结论①跨区皮瓣切取后,静脉扩张是被动扩张,而动脉扩张是主动增值;②跨区皮瓣切取后血流动力学供区与潜力供区之间的choke区参与扩张的choke血管数量及扩张度均小于解剖供区与血流动力学供区之间的choke血管;③小鼠耳瓣模型为研究血管扩张机制及遴选促皮瓣存活药物的理想动物模型。     

Venous congestion and blood flow in free transverse rectus abdominis myocutaneous and deep inferior epigastric perforator flaps

A series of 240 deep inferior epigastric perforator (DIEP) flaps and 271 free transverse rectus abdominis myocutaneous (TRAM) flaps from two institutions was reviewed to determine the incidence of diffuse venous insufficiency that threatened flap survival and required a microvascular anastomosis to drain the superficial inferior epigastric vein. This problem occurred in five DIEP flaps and did not occur in any of the free TRAM flaps. In each of these cases, the presence of a superficial inferior epigastric vein that was larger than usual was noted. It is therefore suggested that if an unusually large superficial inferior epigastric vein is noted when a DIEP flap is elevated, the vein should be preserved for possible use in flap salvage. Anatomical studies with Microfil injections of the superficial venous system of the DIEP or TRAM flap were also performed in 15 cadaver and 3 abdominoplasty specimens to help determine why venous circulation (and flap survival) in zone IV of the flaps is so variable. Large lateral branches crossing the midline were found in only 18 percent of cases, whereas 45 percent had indirect connections through a deeper network of smaller veins and 36 percent had no demonstrable crossing branches at all. This absence of crossing branches in many patients may explain why survival of the zone IV portion of such flaps is so variable and unpredictable.     

An anatomic study of the septocutaneous vessels of the leg

The vascular anatomy of the skin and fascia of the leg were studied in 20 cadaver legs that were injected and dissected under magnification to identify the origin, course, and distribution of vessels from the subfascial level to the skin. In addition to the longitudinally oriented fasciocutaneous arteries and the musculocutaneous perforators, the study demonstrated a third and important system of blood supply: the septocutaneous vessels. These vessels arise directly from the posterior tibial, anterior tibial, and peroneal arteries, run along the intermuscular septum, pierce the crural fascia, and ramify radially in the subcutaneous tissue superficial to the fascia. Longitudinally oriented anastomotic arcades are formed along the leg between branches of adjacent septocutaneous vessels. Each septocutaneous vessel has one or two venae comitantes. Selected methylene blue injections of the septocutaneous vessels revealed rich staining of the superficial surface of the fascia, the subcutaneous tissue, and distinct longitudinally oriented skin territories. There was no injection of dye in the deep surface of the fascia. It is felt that the septocutaneous vessels constitute an important source of skin circulation in the leg and form the basis for various fasciocutaneous flaps that have useful clinical applications.     

Reverse-flow island flap: clinical report and venous drainage

Twenty-two reverse-flow island flaps were transferred. These included peroneal, forearm, anterior tibial, and temporal flaps. Sixteen of 22 flaps survived completely. We encountered partial necrosis in 4 flaps and total necrosis in only 2 flaps. We credit this success to the reliability and availability of the peroneal, forearm, and temporal flaps; but we do not encourage use of the anterior tibial flap. The flaps that survived well did not show any signs of venous congestion. The advantage of the reverse-flow island flap is that it can be transferred from a proximal to a distal location. Using cadavers and fresh amputated limbs, studies on venous drainage of the reverse-flow island flap were performed. The venae comitantes had numerous venous valves and communicating branches, but more than sufficient reflux of the venous blood occurred through the valves at pressures of 90 to 105 cmH2O. We believe that the venous drainage of the reverse-flow island flap occurs as a result of reflux actions at the valve, communicating branches between the venae comitantes, and bypass vessels around the valves.     

Reverse-flow island sural flap

The reverse flow island sural flap is presented as an alternative to flaps currently used for reconstruction of small and medium substance losses in the distal third of the leg, ankle, and heel. This is a random type of flap, based on the reverse flow of the superficial sural artery, which mainly depends on the anatomy of the perforators of the peroneal artery system.The anatomic structures that constitute the pedicle are the superficial and deep fascias, the sural nerve, the short saphenous vein, and the superficial sural artery. The skin island and the subcutaneous cellular tissue complement the flap proper. This skin island was demarcated at any point of the median or distal thirds of the leg, having the short saphenous vein and the sural nerve on its central axis. The distal dissection limit of the pedicle is located 5 centimeters above the lateral malleolus. This limit is established so as to ensure the integrity of the perforators from the principal arteries of the leg, mainly the peroneal artery, responsible for the reverse flow nourishing the flap. These perforators will affect anastomoses with the superficial sural artery in charge of irrigating the structures compounding the flap.A total of 71 patients were operated on with this technique, some of them with basic pathologic abnormalities limiting the distal blood flow, such as diabetes mellitus, and some others having proven vascular insufficiency or displaying unstable areas attributable to problems such as pseudarthrosis and osteomyelitis, which needed to be covered. Fifteen flaps (21.1 percent) suffered partial necrosis, which did not compromise the final result, and another three (4.2 percent) showed total loss. The flap in question has great mobility and versatility, allowing the treatment of specific areas of the lower limb, without sacrificing important arteries or mobilizing structures that might bring about functional deficits.     

Cutaneous blood vessels in scent pigs

The purpose of this study was to systematically provide anatomic data for flap research in plastic surgery on the cutaneous blood vessels. Seven scent pigs used in this study were killed anesthetically, and their carotid vessels were intubated and injected with a black liquid rubber. Twenty-four hours later, the integument of the scent pig was removed, and the perforating points of the cutaneous vessels were recorded. The different-sized pieces of integument became transparent. Part of this transparent skin tissue was cut into cross-sectional strips. There were three types of the cutaneous vascular source, the same as in humans. Six division levels of vessels in the skin were identified, which formed five vascular plexuses and two systems (the perforating vessel system and the cutaneous vessel system). There were two sets of vein systems: the concomitant vein and the oscillating vein; the latter can be divided into regular and irregular types. The structures of the perforating vessel system and the cutaneous vessel system were the morphological basis for choosing flaps. Two anatomic points have been emphasized: the preserved vascular plexus in thin flaps (not the subcutaneous vascular network reported previously) and the dependency of vascular structure on its location. Otherwise, this study has also provided two new kinds of flaps used in experimental study: the arterial loop flap and the intermuscular septal perforator flap. Although there were differences as well as similarities in skin vasculature between humans and the scent pig, the scent pig is still suitable for flap research.