A vascular bypass is a surgical procedure performed to redirect blood flow from one area to another by reconnecting blood vessels. This is done to bypass around a diseased artery, from an area of normal blood flow to another normal area, it is performed due to inadequate blood flow caused by atherosclerosis, as a part of organ transplantation, or for vascular access in hemodialysis. In general, someone's own vein is the preferred graft material for a vascular bypass, but other types of grafts such as polytetrafluoroethylene, polyethylene terephthalate, or a different person's vein are commonly used. Arteries can serve as vascular grafts. A surgeon sews the graft to the source and target vessels by hand using surgical suture, creating a surgical anastomosis. Common bypass sites include the heart to treat coronary artery disease, the legs, to treat peripheral vascular disease. Cardiac bypass is performed when the arteries that bring blood to the heart muscle become clogged by plaque; such a condition may cause chest pain from a heart attack.
In the legs, bypass grafting is used to treat peripheral vascular disease, acute limb ischemia and trauma. While there are many anatomical arrangements for vascular bypass grafts in the lower extremities depending on the location of the disease, the principle is the same: to restore blood flow to an area without normal flow. For example, a femoral-popliteal bypass might be used. A fem-pop bypass may refer to the above- or below-knee popliteal artery. Other anatomic descriptions of lower extremity bypasses include: "fem-fem" - femoral to femoral bypass, e.g. from right to left. Used when there is no inflow to one femoral artery but there is aortic flow. "aorto-bifem" - aortic to both femoral arteries. Used when there is disease at the aortic bifurcation, known as Leriche syndrome, or in both iliac arteries. "ax-bifem" - axillary artery to both femoral artery bypass. Either axillary artery can be used as the origin of the bypass. Used when patient cannot tolerate a more invasive and higher risk aorto-bifem, or when removing an infected aortic graft such as an EVAR device.
"fem-tib" - femoral to one of the three tibial arteries. Used for disease of the femoral and tibial arteries, this procedure is used most in people with diabetes, which tends to create disease in the tibial arteries rather than the more proximal arteries. A "DP" bypass - any vascular bypass where the target is the dorsalis pedis artery on the dorsum of the foot, it is used in similar situations to those described for the fem-tib bypass. A vascular bypass is created to serve as an access point to the circulatory system for hemodialysis; such a bypass is referred to as an arteriovenous fistula if it directly connects a vein to an artery without using synthetic material. In the skull, when blood flow is blocked or a damaged cerebral artery prevents adequate blood flow to the brain, a cerebral artery bypass may be performed to improve or restore flow to an oxygen-deprived area of the brain; when several arteries are blocked and several bypasses are needed, the procedure is called multiple bypass.
The number of bypasses needed does not always increase the risk of surgery, which depend more on the patient's overall health. Prior to constructing a bypass, most surgeons will obtain or perform an imaging study to determine the severity and location of the diseased blood vessels. For cardiac and lower extremity disease, this is in the form of an angiogram. For hemodialysis access, this can be done with ultrasound. A CT angiogram will take the place of a formal angiogram; the lack of an adequate venous conduit is a relative contraindication to bypass surgery, depending on the area of disease, alternatives may be used. Medical conditions such as ischemic heart disease or chronic obstructive pulmonary disease that increase the risk of surgery are relative contraindications. For coronary and peripheral vascular disease, lack of "runoff" to the distal area is a contraindication because a vascular bypass around one diseased artery to another diseased area does not solve the vascular problem. If a patient is deemed to be too high-risk to undergo a bypass, he or she may be a candidate for angioplasty or stenting of the relevant vessel.
Dogma in vascular bypass technique says to obtain distal control. This means that in a vessel with flow through it, a surgeon must be have exposure of the furthest and nearest extents of the blood vessel in which the bypass is being created, so that when the vessel is opened, blood loss is minimized. After the necessary exposure, clamps are used on both the proximal and distal end of the segment. Exceptions exist where there is no blood flow through the target vessel at the area of proposed entry, as is the case with an intervening occlusion. If the organ perfused by an artery is sensitive to temporary occlusion of blood flow, such as in the brain, various other measures are taken. In neurosurgery, excimer laser assisted non-occlusive anastomosis is a technique use to create a bypass without interrupting the blood supply in the recipient blood vessels; this reduces a rupture of an aneurysm. The ELANA technique is a subtle modification of other methods to establish a connection between blood vessels to create a bypass in or to the brain.
The differences involve. In conventional techniques, the recipient artery is temporarily interrupted and ope
The ovarian artery is an artery that supplies oxygenated blood to the ovary in females. It arises from the abdominal aorta below the renal artery, it can anterior to the ovarian vein and ureter. The ovarian arteries are paired structures that arise from the abdominal aorta at the level of L2. After emerging from the aorta, the artery travels down the suspensory ligament of the ovary, enters the mesovarium, may anastamose with the uterine artery in the broad ligament; the ovarian arteries are the corresponding arteries in the female to the testicular artery in the male. They are shorter than the internal spermatics; the origin and course of the first part of each artery are the same as those of the internal spermatic, but on arriving at the upper opening of the lesser pelvis the ovarian artery passes inward, between the two layers of the ovariopelvic ligament and of the broad ligament of the uterus, to be distributed to the ovary. Small branches are given to the ureter and the uterine tube, one passes on to the side of the uterus, unites with the uterine artery.
Other offsets are continued on the round ligament of the uterus, through the inguinal canal, to the integument of the labium majus and groin. The ovarian artery supplies blood to the uterus; the ovarian arteries swell during pregnancy. "Anastomoses Between Utero - Ovarian Arteries, Variations" at anatomyatlases.org pelvis at The Anatomy Lesson by Wesley Norman figures/chapter_35/35-9. HTM: Basic Human Anatomy at Dartmouth Medical School
Blood is a body fluid in humans and other animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells. In vertebrates, it is composed of blood cells suspended in blood plasma. Plasma, which constitutes 55% of blood fluid, is water, contains proteins, mineral ions, carbon dioxide, blood cells themselves. Albumin is the main protein in plasma, it functions to regulate the colloidal osmotic pressure of blood; the blood cells are red blood cells, white blood cells and platelets. The most abundant cells in vertebrate blood are red blood cells; these contain hemoglobin, an iron-containing protein, which facilitates oxygen transport by reversibly binding to this respiratory gas and increasing its solubility in blood. In contrast, carbon dioxide is transported extracellularly as bicarbonate ion transported in plasma. Vertebrate blood is bright red when its hemoglobin is oxygenated and dark red when it is deoxygenated.
Some animals, such as crustaceans and mollusks, use hemocyanin to carry oxygen, instead of hemoglobin. Insects and some mollusks use a fluid called hemolymph instead of blood, the difference being that hemolymph is not contained in a closed circulatory system. In most insects, this "blood" does not contain oxygen-carrying molecules such as hemoglobin because their bodies are small enough for their tracheal system to suffice for supplying oxygen. Jawed vertebrates have an adaptive immune system, based on white blood cells. White blood cells help to resist parasites. Platelets are important in the clotting of blood. Arthropods, using hemolymph, have hemocytes as part of their immune system. Blood is circulated around the body through blood vessels by the pumping action of the heart. In animals with lungs, arterial blood carries oxygen from inhaled air to the tissues of the body, venous blood carries carbon dioxide, a waste product of metabolism produced by cells, from the tissues to the lungs to be exhaled.
Medical terms related to blood begin with hemo- or hemato- from the Greek word αἷμα for "blood". In terms of anatomy and histology, blood is considered a specialized form of connective tissue, given its origin in the bones and the presence of potential molecular fibers in the form of fibrinogen. Blood performs many important functions within the body, including: Supply of oxygen to tissues Supply of nutrients such as glucose, amino acids, fatty acids Removal of waste such as carbon dioxide and lactic acid Immunological functions, including circulation of white blood cells, detection of foreign material by antibodies Coagulation, the response to a broken blood vessel, the conversion of blood from a liquid to a semisolid gel to stop bleeding Messenger functions, including the transport of hormones and the signaling of tissue damage Regulation of core body temperature Hydraulic functions Blood accounts for 7% of the human body weight, with an average density around 1060 kg/m3 close to pure water's density of 1000 kg/m3.
The average adult has a blood volume of 5 litres, composed of plasma and several kinds of cells. These blood cells consist of erythrocytes and thrombocytes. By volume, the red blood cells constitute about 45% of whole blood, the plasma about 54.3%, white cells about 0.7%. Whole blood exhibits non-Newtonian fluid dynamics. If all human hemoglobin were free in the plasma rather than being contained in RBCs, the circulatory fluid would be too viscous for the cardiovascular system to function effectively. One microliter of blood contains: 4.7 to 6.1 million, 4.2 to 5.4 million erythrocytes: Red blood cells contain the blood's hemoglobin and distribute oxygen. Mature red blood cells lack a nucleus and organelles in mammals; the red blood cells are marked by glycoproteins that define the different blood types. The proportion of blood occupied by red blood cells is referred to as the hematocrit, is about 45%; the combined surface area of all red blood cells of the human body would be 2,000 times as great as the body's exterior surface.
4,000–11,000 leukocytes: White blood cells are part of the body's immune system. The cancer of leukocytes is called leukemia. 200,000 -- 500,000 thrombocytes: Also called platelets. Fibrin from the coagulation cascade creates a mesh over the platelet plug. About 55% of blood is blood plasma, a fluid, the blood's liquid medium, which by itself is straw-yellow in color; the blood plasma volume totals of 2.7–3.0 liters in an average human. It is an aqueous solution containing 92% water, 8% blood plasma proteins, trace amounts of other materials. Plasma circulates dissolved nutrients, such as glucose, amino acids, fatty acids, removes waste products, such as carbon dioxide and lactic acid. Other important components include: Serum albumin Blood-clotting factors Immunoglobulins lipoprotein particles Various
Anatomical terms of location
Standard anatomical terms of location deal unambiguously with the anatomy of animals, including humans. All vertebrates have the same basic body plan – they are bilaterally symmetrical in early embryonic stages and bilaterally symmetrical in adulthood; that is, they have mirror-image left and right halves if divided down the middle. For these reasons, the basic directional terms can be considered to be those used in vertebrates. By extension, the same terms are used for many other organisms as well. While these terms are standardized within specific fields of biology, there are unavoidable, sometimes dramatic, differences between some disciplines. For example, differences in terminology remain a problem that, to some extent, still separates the terminology of human anatomy from that used in the study of various other zoological categories. Standardized anatomical and zoological terms of location have been developed based on Latin and Greek words, to enable all biological and medical scientists to delineate and communicate information about animal bodies and their component organs though the meaning of some of the terms is context-sensitive.
The vertebrates and Craniata share a substantial heritage and common structure, so many of the same terms are used for location. To avoid ambiguities this terminology is based on the anatomy of each animal in a standard way. For humans, one type of vertebrate, anatomical terms may differ from other forms of vertebrates. For one reason, this is because humans have a different neuraxis and, unlike animals that rest on four limbs, humans are considered when describing anatomy as being in the standard anatomical position, thus what is on "top" of a human is the head, whereas the "top" of a dog may be its back, the "top" of a flounder could refer to either its left or its right side. For invertebrates, standard application of locational terminology becomes difficult or debatable at best when the differences in morphology are so radical that common concepts are not homologous and do not refer to common concepts. For example, many species are not bilaterally symmetrical. In these species, terminology depends on their type of symmetry.
Because animals can change orientation with respect to their environment, because appendages like limbs and tentacles can change position with respect to the main body, positional descriptive terms need to refer to the animal as in its standard anatomical position. All descriptions are with respect to the organism in its standard anatomical position when the organism in question has appendages in another position; this helps avoid confusion in terminology. In humans, this refers to the body in a standing position with arms at the side and palms facing forward. While the universal vertebrate terminology used in veterinary medicine would work in human medicine, the human terms are thought to be too well established to be worth changing. Many anatomical terms can be combined, either to indicate a position in two axes or to indicate the direction of a movement relative to the body. For example, "anterolateral" indicates a position, both anterior and lateral to the body axis. In radiology, an X-ray image may be said to be "anteroposterior", indicating that the beam of X-rays pass from their source to patient's anterior body wall through the body to exit through posterior body wall.
There is no definite limit to the contexts in which terms may be modified to qualify each other in such combinations. The modifier term is truncated and an "o" or an "i" is added in prefixing it to the qualified term. For example, a view of an animal from an aspect at once dorsal and lateral might be called a "dorsolateral" view. Again, in describing the morphology of an organ or habitus of an animal such as many of the Platyhelminthes, one might speak of it as "dorsiventrally" flattened as opposed to bilaterally flattened animals such as ocean sunfish. Where desirable three or more terms may be agglutinated or concatenated, as in "anteriodorsolateral"; such terms sometimes used to be hyphenated. There is however little basis for any strict rule to interfere with choice of convenience in such usage. Three basic reference planes are used to describe location; the sagittal plane is a plane parallel to the sagittal suture. All other sagittal planes are parallel to it, it is known as a "longitudinal plane".
The plane is perpendicular to the ground. The median plane or midsagittal plane is in the midline of the body, divides the body into left and right portions; this passes through the head, spinal cord, and, in many animals, the tail. The term "median plane" can refer to the midsagittal plane of other structures, such as a digit; the frontal plane or coronal plane divides the body into ventral portions. For post-embryonic humans a coronal plane is vertical and a transverse plane is horizontal, but for embryos and quadrupeds a coronal plane is horizontal and a transverse plane is vertical. A longitudinal plane is any plane perpendicular to the transverse plane; the coronal plane and the sagittal plane are examples of longitudinal planes. A transverse plane known as a cross-section, divides the body into cranial and caudal portions. In human anatomy: A transverse plane is an X-Z plane, parallel to the ground, which s
International Standard Serial Number
An International Standard Serial Number is an eight-digit serial number used to uniquely identify a serial publication, such as a magazine. The ISSN is helpful in distinguishing between serials with the same title. ISSN are used in ordering, interlibrary loans, other practices in connection with serial literature; the ISSN system was first drafted as an International Organization for Standardization international standard in 1971 and published as ISO 3297 in 1975. ISO subcommittee TC 46/SC 9 is responsible for maintaining the standard; when a serial with the same content is published in more than one media type, a different ISSN is assigned to each media type. For example, many serials are published both in electronic media; the ISSN system refers to these types as electronic ISSN, respectively. Conversely, as defined in ISO 3297:2007, every serial in the ISSN system is assigned a linking ISSN the same as the ISSN assigned to the serial in its first published medium, which links together all ISSNs assigned to the serial in every medium.
The format of the ISSN is an eight digit code, divided by a hyphen into two four-digit numbers. As an integer number, it can be represented by the first seven digits; the last code digit, which may be 0-9 or an X, is a check digit. Formally, the general form of the ISSN code can be expressed as follows: NNNN-NNNC where N is in the set, a digit character, C is in; the ISSN of the journal Hearing Research, for example, is 0378-5955, where the final 5 is the check digit, C=5. To calculate the check digit, the following algorithm may be used: Calculate the sum of the first seven digits of the ISSN multiplied by its position in the number, counting from the right—that is, 8, 7, 6, 5, 4, 3, 2, respectively: 0 ⋅ 8 + 3 ⋅ 7 + 7 ⋅ 6 + 8 ⋅ 5 + 5 ⋅ 4 + 9 ⋅ 3 + 5 ⋅ 2 = 0 + 21 + 42 + 40 + 20 + 27 + 10 = 160 The modulus 11 of this sum is calculated. For calculations, an upper case X in the check digit position indicates a check digit of 10. To confirm the check digit, calculate the sum of all eight digits of the ISSN multiplied by its position in the number, counting from the right.
The modulus 11 of the sum must be 0. There is an online ISSN checker. ISSN codes are assigned by a network of ISSN National Centres located at national libraries and coordinated by the ISSN International Centre based in Paris; the International Centre is an intergovernmental organization created in 1974 through an agreement between UNESCO and the French government. The International Centre maintains a database of all ISSNs assigned worldwide, the ISDS Register otherwise known as the ISSN Register. At the end of 2016, the ISSN Register contained records for 1,943,572 items. ISSN and ISBN codes are similar in concept. An ISBN might be assigned for particular issues of a serial, in addition to the ISSN code for the serial as a whole. An ISSN, unlike the ISBN code, is an anonymous identifier associated with a serial title, containing no information as to the publisher or its location. For this reason a new ISSN is assigned to a serial each time it undergoes a major title change. Since the ISSN applies to an entire serial a new identifier, the Serial Item and Contribution Identifier, was built on top of it to allow references to specific volumes, articles, or other identifiable components.
Separate ISSNs are needed for serials in different media. Thus, the print and electronic media versions of a serial need separate ISSNs. A CD-ROM version and a web version of a serial require different ISSNs since two different media are involved. However, the same ISSN can be used for different file formats of the same online serial; this "media-oriented identification" of serials made sense in the 1970s. In the 1990s and onward, with personal computers, better screens, the Web, it makes sense to consider only content, independent of media; this "content-oriented identification" of serials was a repressed demand during a decade, but no ISSN update or initiative occurred. A natural extension for ISSN, the unique-identification of the articles in the serials, was the main demand application. An alternative serials' contents model arrived with the indecs Content Model and its application, the digital object identifier, as ISSN-independent initiative, consolidated in the 2000s. Only in 2007, ISSN-L was defined in the
The uterine artery is an artery that supplies blood to the uterus in females. The uterine artery arises from the anterior division of the internal iliac artery, it travels to the uterus, crossing the ureter anteriorly, to the uterus by traveling in the cardinal ligament. It travels through the parametrium of the inferior broad ligament of the uterus, it anastomoses the ovarian artery. The uterine artery is the major blood supply to the uterus and enlarges during pregnancy. Round ligament of the uterus ovary uterus vagina uterine tube Uterine artery embolization Uterine leiomyomata Anatomy photo:43:13-0204 at the SUNY Downstate Medical Center - "The Female Pelvis: Branches of Internal Iliac Artery" pelvis at The Anatomy Lesson by Wesley Norman
Myomectomy, sometimes fibroidectomy, refers to the surgical removal of uterine leiomyomas known as fibroids. In contrast to a hysterectomy the uterus remains preserved and the woman retains her reproductive potential; the presence of a fibroid does not mean. Removal is necessary when the fibroid causes pain or pressure, abnormal bleeding, or interferes with reproduction; the fibroids needed to be removed are large in size, or growing at certain locations such as bulging into the endometrial cavity causing significant cavity distortion. Patients have many options in the management of uterine fibroids, including: observation, medical therapy, uterine artery embolization, high-intensity focused ultrasound ablation. Despite these many options, the surgical approach of selected fibroid removal remains an important choice for those women who want or need to preserve the uterus. A myomectomy can be performed in a number of ways, depending on the location and number of lesions and the experience and preference of the surgeon.
Either a general or a spinal anesthesia is administered. Traditionally a myomectomy is performed via a laparotomy with a full abdominal incision, either vertically or horizontally. Once the peritoneal cavity is opened, the uterus is incised, the lesion removed; the open approach is preferred for larger lesions. One or more incisions may be set into the uterine muscle and are repaired once the fibroid has been removed. Recovery after surgery takes six to eight weeks. Using the laparoscopic approach the uterus is visualized and its fibroids removed. Studies have suggested that laparoscopic myomectomy leads to lower morbidity rates and faster recovery than does laparotomic myomectomy; as with hysteroscopic myomectomy, laparoscopic myomectomy is not used on large fibroids. A study of laparoscopic myomectomies conducted between January 1990 and October 1998 examined 106 cases of laparoscopic myomectomy, in which the fibroids were intramural or subserous and ranged in size from 3 to 10 cm. A fibroid, located in a submucous position may be accessible to hysteroscopic removal.
This may apply to smaller lesions as pointed out by a large study that collected results from 235 patients suffering from submucous myomas who were treated with hysteroscopic myomectomies. However, larger lesions have been treated by hysteroscopy. Recovery after hysteroscopic surgery is but a few days. Complications of the surgery include the possibility of significant blood loss leading to a blood transfusion, the risk of adhesion or scar formation around the uterus or within its cavity, the possible need to deliver via cesarean section, it may not be possible to remove all lesions, nor will the operation prevent new lesions from growing. Development of new fibroids will be seen in 42-55% of patients undergoing a myomectomy, it is well known that myomectomy surgery is associated with a higher risk of uterine rupture in pregnancy. Thus, women who have had myomectomy should get Cesarean delivery to avoid the risk of uterine rupture, fatal to the fetus. To reduce bleeding during myomectomy, the use of misoprostol in the vagina and the injection of vasopressin into the uterine muscle are both effective.
There is less evidence supporting the usefulness chemical dissection, vaginal insertion of dinoprostone, a gelatin-thrombin matrix, tranexamic acid, infusion of vitamin C, infiltration of a mixture of bupivacaine and epinephrine into the uterine muscles, or the use of a fibrin sealant patch. Leiomyomata tend to grow during pregnancy but only the large ones causing endometrial cavity distortion could interfere with the growing pregnancy directly. Surgeons tend to stay away from operative interventions during the pregnancy because of the risk of haemorrhage and the concern that the pregnancy may be interrupted. After a pregnancy, myomas tend to shrink naturally. However, in selected cases myomectomy may become necessary during pregnancy, or at the time of a caesarean section to gain access to the baby. Http://www.merciafibroidclinic.com/Fibroids-Treatments/Myomectomy-Laparoscopic/myomectomy-laparoscopic.html