Hemolymph Node - An Immunomorphlogical Organ: Modeling the Hemolymph Node by Allografting Renal Tissue in the Rat.

There is no authoritative characterization of the attributes of the hemolymph node (HLN) since Gibbes' first description in 1884. Early reports showed that HLN are found near the kidney in human and animals with the feature of numerous erythrocytes in sinuses. Subsequent studies mainly focused on anatomy and histology, such as the source, distribution, and quantity of erythrocytes in sinuses. Recent articles mentioned that the emergence of HLN was related to immunity, but there was no strong evidence to support this hypothesis. Therefore, it is still uncertain whether the HLN is an organ of anatomy, histology, or immunology. It has been found that the development of HLN could be elicited in the parathymic area by stimuli such as Escherichia coli, allogeneic breast cancer cells, and renal tissue that were injected/transplanted into the tail of rats in our pilot studies. In this study, the model of the HLN was established by transferring allogeneic renal tissue in the rat. Intrasinusoidal erythrocytes of the node were the component for producing a red macroscopic appearance, while macrophage-erythrocyte-lymphocyte rosettes were the major immunomorphological changes, reflecting the immune activity against the invasion of the allogeneic tissue within the node. Therefore, the HLN is an immunomorphological organ.

Perforating and deep lymphatic vessels in the knee region: an anatomical study and clinical implications.

BACKGROUND: To determine the relationship between the perforating and deep lymphatic vessels in the knee region for clinical implications. METHODS: Four lower limbs from two unembalmed human cadavers were used. Under a surgical microscope, 6% hydrogen peroxide was employed to detect lymph vessels accompanying the small saphenous vein, anterior tibial, posterior tibial and fibular blood vessels all commencing from distal ends of specimens. Each lymphatic vessel was inserted by a 30-gauge needle and injected with a barium sulphate mixture. Each specimen was dissected, radiographed and photographed to determine the perforating and deep lymphatic vessels in the region. RESULTS: A perforating lymph vessel was observed in the popliteal fossa of each specimen. It arose from the superficial popliteal lymph node and terminated in the deep popliteal lymph node. The anterior tibial, posterior tibial and peroneal lymph vessels were discovered in the region travelling with the corresponding vascular bundles. After penetrating the vascular aperture of the interosseous membrane between the tibia and fibula, the anterior tibial lymph vessel entered directly into the deep popliteal lymph node or converged to either the posterior tibial or fibular lymph vessel, before entering the node. The posterior tibial and peroneal lymph vessels entered the deep popliteal lymph node. The efferent lymph vessel of the deep popliteal lymph node travelled with the femoral vascular bundle. CONCLUSION: The perforating and deep lymphatic vessels in the knee region has been presented and discussed. The information advances our anatomical knowledge and the results will benefit clinical management.

Divergent lymphatic drainage routes from the heel to the inguinal region: anatomic study and clinical implications.

PURPOSE: To determine routes of lymphatic drainage from the heel to the inguinal lymph nodes to assist in the clinical management of lower limb lymphatic disorders. METHODS: Six lower limbs from three unembalmed human cadavers were studied. Under a surgical microscope, 6% hydrogen peroxide was used to detect lymphatic vessels on the medial and lateral sides of the heel. The lymphatic vessel on either side was then injected with a radio-opaque mixture. The lymphatic vessels were traced, photographed, and radiographed to demonstrate the lymphatic pathways from the heel to the inguinal lymph nodes. The final results were transferred to computer for digital image analysis. RESULTS: Two groups of lymph collecting vessels were identified. The medial group, arising from the skin between the medial malleolus and the Achilles tendon, coursed along the medial side of the leg and thigh to the inguinal lymph nodes. The lateral group, arising from the skin between the lateral malleolus and the Achilles tendon, coursed along the postero-lateral side of the leg to the popliteal fossa. Alternative routes were then identified from the popliteal fossa to the inguinal lymph nodes. The number, size, type, and distribution of lymph vessels and nodes were variable from person to person. CONCLUSION: Two different lymphatic routes from the heel to the inguinal lymph nodes have been described. This information upgrades current anatomical knowledge and the results will be of benefit for the clinical management of lower limb trauma and malignancy.

Superficial lymphatic drainage of the lower extremity: anatomical study and clinical implications.

BACKGROUND: Knowledge of the lymphatic anatomy in the lower extremity is inadequate. A reevaluation is needed to assist in guiding clinical management. METHODS: A total of five lower extremities from three unembalmed human cadavers were studied. Under a surgical microscope, 6% hydrogen peroxide was used to detect the lymphatic vessels commencing from the foot, the leg, and the thigh. A 30-gauge needle was inserted into the vessels and injected with a radiopaque lead oxide mixture. The vessels were traced, photographed, and radiographed to demonstrate the superficial lymphatic pathways of the lower extremity. The final results were transferred to the computer for image analysis. RESULTS: Numerous lymph collecting vessels were identified in the subcutaneous tissue and the superficial femoral vascular bundle of the lower extremity. They originated beneath the dermis of each side of the toes, the foot, and the lateral side of the thigh. The diameters of the vessels varied from 0.2 to 2.2 mm. The vessels traveled in the subcutaneous tissue of the lower limb toward the popliteal, femoral, superficial, and deep inguinal lymph nodes. During their tortuous course, some vessels branched, diverged, and converged; sometimes, they anastomosed with neighboring vessels or crossed them. Most vessels converged to form larger collectors and then diverged into small branches before entering the lymph nodes. CONCLUSIONS: Accurate lymphatic distribution within the lower extremity has been described. This information upgrades our anatomical knowledge, and the results will be of benefit for clinical management.

Arterial supply of the tendinous rotator cuff insertions: an anatomical study.

BACKGROUND: Confirming the presence of arteries crossing the osteotendinous junctions (OTJs) of the rotator cuff may explain why rates of avascular necrosis (AVN) of the humeral head vary between three- and four-part proximal humeral fractures. It is hypothesized that the humeral head remains better vascularized in three-part fractures because one tuberosity with its inserting rotator cuff tendons is still attached to the articular fragment and supplying it with blood. METHODS: Eighty rotator cuff tendons from 20 shoulder girdles of cadavers aged 68-94 years were studied. In six shoulder girdles, the anterior circumflex humeral artery and posterior circumflex humeral artery (PCHA) were injected with ink, and the extra- and intraosseous courses of the vasculature were dissected until the OTJs of the rotator cuff. RESULTS: The rotator cuff insertions received an arterial supply across their OTJs in 50% of cases (75% in supraspinatus, 67% in subscapularis, 33% in infraspinatus and 20% in teres minor). Supraspinatus and subscapularis insertions were vascularized by the arcuate artery, while the insertions of infraspinatus and teres minor were supplied by an unnamed terminal branch of the PCHA. This was named 'posterolateral artery'. CONCLUSION: The presence of arteries crossing the OTJs of the rotator cuff, as well as the differences in the frequency arteries crossed the OTJs of individual rotator cuff tendons, may help explain why there is a lower rate of AVN of the humeral head in thee-part, compared with four-part proximal humeral fractures.

New approach to the study of intraosseous vasculature.

BACKGROUND: The study of intraosseous vasculature has always been challenging due to the hard, calcified structure of bone. Techniques used to study intraosseous vasculature usually involve diaphanization with a Spalteholz technique, followed by X-ray imaging to display the radio contrast-injected blood vessels. These techniques produce results with fine detail when successfully executed. However, high failure rates and the extensive length of time required to perform these techniques are drawbacks. This paper describes a faster, alternative method for the study of intraosseous vasculature. METHOD: Five embalmed and two fresh shoulder girdles were harvested from six cadavers. Cannulas were inserted into the origins of the anterior (ACHA) and posterior (PCHA) circumflex humeral arteries and injected with ink diluted in water or 6% hydrogen peroxide. The arteries and their branches were dissected until they entered their respective bony foraminae. A hammer, chisel, bone nibbler and mounted needles were used to follow the intraosseous course of these arteries and their branches. RESULTS: The intraosseous vasculature was seen in all specimens. The branches of the main nutrient artery to the proximal humerus were followed until they reached articular cartilage or crossed cortical bone again to enter the rotator cuff tendons. DISCUSSION: An innovative, new approach to the study of intraosseous vasculature with direct visualization of the intraosseous arteries of the proximal humerus is described.

Preventing venous congestion of the nipple-areola complex: an anatomical guide to preserving essential venous drainage networks.

BACKGROUND: Venous congestion leading to partial or total nipple necrosis is a relatively uncommon complication of breast reduction and mastopexy procedures but still occurs, particularly in larger reduction procedures. This is largely preventable if the surgeon has an understanding of the venous drainage to the nipple and carefully preserves it. METHODS: An anatomical study was undertaken on 16 fresh female cadaveric breast specimens. The venous drainage of the breast was explored through vascular injection, radiographic, and cross-sectional studies. RESULTS: The venous drainage of the breast consists of an extensive network of vessels. The nipple-areola complex is drained by a superficial subareolar ring of veins that drains by means of medial and lateral veins. Laterally, superolateral and inferolateral veins drain into the subclavian veins, whereas medially, two veins drain into the internal mammary veins. An inferior vein drains the inferior quadrant of the breast in the midmammary line. Medially, the veins have a superficial course, whereas laterally, the veins follow a deeper course. CONCLUSIONS: The breast contains an extensive venous network. To avoid necrosis of the nipple-areola complex, this venous network should be preserved. The superomedial/medial and inferior pedicles contain the most extensive and more reliable venous drainage patterns.

Variations in the lymphatic drainage pattern of the head and neck: further anatomic studies and clinical implications.

BACKGROUND: There is an increasing clinical need for accurate evaluation of the lymphatic anatomy of the head and neck. METHODS: Fourteen halves of the superficial tissues of the head and neck and six specimens of the anterior superficial neck tissue from 13 unembalmed human cadavers were studied. Six percent hydrogen peroxide was used to detect the lymphatic vessels by using a surgical microscope. These vessels were then injected with a radio-opaque lead oxide mixture. Each specimen was dissected, photographed, and radiographed to demonstrate lymphatic vessels in the tissue. The final results were then transferred to the computer for analysis. RESULTS: Lymph-collecting vessels were found in three regions of the superficial tissue of the head and neck: the scalp, face, and cervical region. They were dense in the scalp and lateral neck area but sparse in the facial, anterior, and posterior neck. Most vessels in the lateral neck were internodal lymphatics. Two layers of lymphatic vessels were found in the anterior superficial neck tissue coursing in different directions. CONCLUSIONS: An actual and accurate lymphatic map of the head and neck lymphatic drainage patterns is presented to upgrade our anatomical knowledge. This map will be of benefit for the clinical management of trauma and malignancies in this region.

Lymphatic drainage of the external ear.

BACKGROUND: Lymphoscintigraphy reveals inconsistencies in our knowledge of the lymphatic anatomy of the external ear. METHODS: Fifteen external ears from 9 unembalmed human cadavers were studied. Six percent hydrogen peroxide was used to find the lymphatic vessels using a surgical microscope. They were injected with a radio-opaque mixture, dissected, photographed, and radiographed to demonstrate lymphatic vessels in the tissue. Final results were transferred to the computer for analysis. RESULTS: Four groups of lymph collecting vessels were found. The anterior branch, in all specimens, drained directly or indirectly (having merged with a vessel descending from the scalp) into the preauricular lymph nodes. The superior, middle, and inferior (lobule) branches drained to their multiple first tier lymph nodes. CONCLUSION: An accurate lymphatic map of the external ear is described to upgrade our anatomic knowledge. It will be of benefit for the clinical management of malignancies in this region.

Alternative lymphatic drainage routes from the lateral heel to the inguinal lymph nodes: anatomic study and clinical implications.

BACKGROUND: The route of lymphatic drainage from the heel to the inguinal lymph nodes is required to be accurately evaluated for clinical needs. METHODS: Seven lower limbs from four unembalmed human cadavers were studied. Under a surgical microscope, 6% hydrogen peroxide was used to detect the lymphatic vessel on the lateral side of the heel. The vessel was then injected with a radio-opaque lead oxide mixture. The vessel was traced, photographed and radiographed to demonstrate the lymphatic pathways from the lateral heel to the inguinal lymph nodes. The final results were transferred to the computer for image analysis. RESULTS: The lymph collecting vessel arising from the skin of the fossa between the lateral malleolus and the Achilles tendon ran along the posterolateral side of the leg, deep to the superficial fascia. From the popliteal fossa to the inguinal lymph nodes, three lymphatic routes were found: (i) via the superficial tissue of the medial side of the thigh; (ii) running with the superficial femoral blood vessels; (iii) running between the sciatic nerve and the profunda femoral vessels. The number and type of lymph nodes found in the popliteal fossa and femoral triangle were different from person to person. CONCLUSION: Actual and accurate lymphatic routes from the skin above the posterolateral heel to the inguinal lymph nodes have been described. This information upgrades our anatomical knowledge and the results will be of benefit for the clinical management of trauma and malignancies in the lower limb.

The pudendal thigh flap for vaginal reconstruction: optimising flap survival.

BACKGROUND: The pudendal thigh fasciocutaneous (PTF) flap is a useful flap in perineal reconstruction, that is reliable when small but is traditionally unreliable when large flaps are raised. Large flaps in particular, are associated with an increased incidence of apical necrosis. Thorough descriptions of the vascular anatomy of this flap have been lacking from the literature, with the current study evaluating this anatomy, aiming to provide the anatomical basis for vascular problems and for techniques to maximise its survival. METHODS: Five unembalmed human cadaveric pelvis specimens were studied. Lead oxide injectant enabled radiographic and dissection analysis of the arterial anatomy of the integument of the perineum. RESULTS: A consistent pattern of vascular supply was found in all specimens. 1: the blood supply to the pelvic floor was supplied sequentially by the posterior labial/scrotal arteries, cutaneous branches from the anterior branch of the obturator artery, and branches from the external pudendal arteries. 2: these vessels ran close to the midline, medial to the PTF flap. 3: the posterior labial/scrotal arteries were deep to the Colles' fascia and the branches from the obturator artery and external pudendal arteries were located superficial to the Colles' fascia. CONCLUSION: This study has demonstrated that the PTF flap is a three vascular territory flap and that the pedicle is situated close to the midline. This may explain why regions of the PTF flap may have a potentially precarious blood supply, and suggests that the PTF flap should be designed more medially. Given the third territory of supply to the apex of the flap, a delay procedure may help to avoid flap necrosis.

The perforator angiosome: a new concept in the design of deep inferior epigastric artery perforator flaps for breast reconstruction.

BACKGROUND: The previously described "perfusion zones" of the abdominal wall vasculature are based on filling of the deep inferior epigastric artery (DIEA) and all its branches simultaneously. With the advent of the DIEA perforator flap, only a single or several perforators are included in supply to the flap. As such, a new model for abdominal wall perfusion has become necessary. The concept of a "perforator angiosome" is thus explored. METHODS: A clinical and cadaveric study of 155 abdominal walls was undertaken. This comprised the use of 10 whole, unembalmed cadaveric abdominal walls for angiographic studies, and 145 abdominal wall computed tomographic angiograms (CTAs) in patients undergoing preoperative imaging of the abdominal wall vasculature. The evaluation of the subcutaneous branching pattern and zone of perfusion of individual DIEA perforators was explored, particularly exploring differences between medial and lateral row perforators. RESULTS: Fundamental differences exist between medial row and lateral row perforators, with medial row perforators larger (1.3 mm vs. 1 mm) and more likely to ramify in the subcutaneous fat toward the contralateral hemiabdomen (98% of cases vs. 2% of cases). A model for the perfusion of the abdominal wall based on a single perforator is presented. CONCLUSION: The "perforator angiosome" is dependent on perforator location, and can mapped individually with the use of preoperative imaging.

Preserving the neurovascular supply in the Hall-Findlay superomedial pedicle breast reduction: an anatomical study.

BACKGROUND: The Hall-Findlay superomedial pedicle technique is widely used for breast reduction, and, despite low complication rates, nipple-areola complex (NAC) necrosis and denervation are still the two most common complications, particularly when resection volumes exceed 600g. An understanding of the anatomy of the neurovascular pedicle of the NAC is paramount in avoiding these complications. METHODS: An anatomical study was undertaken on 11 female cadaveric breast specimens (nine fresh and two embalmed). The neurovascular anatomy of the breast was explored through dissection, microdissection, radiographic, computed tomographic, photographic and cross-sectional studies. The superomedial pedicle was mapped out on each specimen, and the course of the relevant nerves and vasculature was identified. RESULTS: The arterial supply to the superomedial pedicle was found to originate from a single dominant vessel in each specimen, while the venous drainage was via an extensive branching network. Both vascular patterns traversed the pedicle in a superficial plane. The innervation of the pedicle was via intercostal branches, which coursed extremely superficially in the pedicle. CONCLUSION: De-epithelialisation or superficial thinning of the superomedial pedicle for breast reduction is at high risk for complications related to vascular compromise or denervation. Where greater resection is needed, this should be done from the deep surface or the base of the pedicle, contrary to previous descriptions.

The venous anatomy of the anterior abdominal wall: an anatomical and clinical study.

BACKGROUND: Despite improving outcomes, venous problems in the harvest of deep inferior epigastric artery perforator (DIEP) flaps remain the more common vascular complications. However, it is apparent that the venous anatomy of the anterior abdominal wall has not been described to the same extent as the arterial anatomy. Previous anatomical studies have focused on cadaveric anatomy or excisional specimens. The current study uses in vivo computed tomographic angiography to evaluate this anatomy, in combination with a cadaveric radiographic study. METHODS: Both cadaveric and in vivo studies were undertaken using eight whole fresh cadaveric specimens (16 sides) and 100 patients undergoing DIEP flap breast reconstruction (200 sides). The cadaveric component used direct catheter venography and the in vivo studies were undertaken using preoperative computed tomographic angiography, mapping in vivo venous flow. RESULTS: : The location, caliber, course, and distribution of the superficial and deep inferior epigastric veins were recorded. The dominance of each system and their direction of drainage were described. Mechanisms for poor venous drainage were postulated, including perforator size, midline crossover of the superficial inferior epigastric vein, and the superficial and deep inferior epigastric vein communications. The incidence of each of these anatomical factors was evaluated. CONCLUSION: The cause of venous compromise is multifactorial, with the current study showing that preoperative computed tomographic angiography may predict venous problems during flap harvest, by demonstrating perforator diameter, midline crossover, and deep-superficial venous communications.

A three-dimensional analysis of the lymphatics of a bilateral breast specimen: a human cadaveric study.

BACKGROUND: There is an increasing clinical need for evaluation of the lymphatic anatomy of the breast. Because of tissue putrefaction, previous studies have not been able to achieve radiographic analyses of bilateral breasts in cadaver specimens. The use of improved preservation techniques with computed tomographic lymphangiography (CT; CTL) has now allowed this analysis to be undertaken. MATERIALS AND METHODS: The bilateral breasts and anterior upper torso from a female unembalmed human cadaver was studied over an 8-week period. Using microsurgical techniques, lymphatic vessels were identified with hydrogen peroxide, injected with lead oxide mixture, and radiographed to demonstrate lymphatic vessels in both breasts. Multiple frozen domestic ice bricks were used to cover the contralateral side of tissues to keep them partially frozen during this lengthy process. The specimen was radiographed, CT scanned, cross-sectioned, and radiographed again, with images digitalized for analysis. RESULTS: A three-dimensional analysis of lymph collecting vessels in the breasts, anterior upper torso and the internal mammary vascular bundles was achieved using both plain radiography and CTL. The lymphatics of the breast and anterior upper torso drain radially into the axillary lymph nodes. A predominance of superficial lymphatics are noted. Importantly, lymphatic vessel patterns of the breast are asymmetric between breasts of each side. CONCLUSION: Three-dimensional images of the lymphatic drainage of the breasts using advanced imaging technologies are described, with lymphangiography achieved in bilateral cadaveric breasts and anterior upper torso for the first time. This has significant future application for clinical practice.

The lumbar artery perforators: a cadaveric and clinical anatomical study.

BACKGROUND: The lumbar region has been scarcely explored as a donor site for free tissue transfer or as a free flap recipient site. The lumbar integument provides a versatile prospective flap site, with a potentially well-concealed scar. Similarly, defects of this region can require recipient vessels that may be difficult to identify. Although lumbar artery perforators have been described, the reliability of perforators in this region remains questionable. METHODS: An anatomical study was undertaken combining both cadaveric and in vivo analysis of the lumbar vessels. The cadaveric component comprised both dissection and angiographic studies in fresh and embalmed cadavers (36 lumbar regions in 18 cadavers), and the clinical study comprised a computed tomographic angiographic study (44 sides in 22 patients) and an operative case report. RESULTS: Perforators were shown to arise from all eight lumbar arteries to enter the lumbar integument, with their size, location, and course described. Lower lumbar perforators were more often septocutaneous and of larger caliber. A case in which the fourth lumbar artery and concomitant vein were used as free flap recipient vessels is described, the first such reported case in the literature. CONCLUSIONS: Improving the incidence of identifying lumbar perforators of large caliber and with a septocutaneous course can be achieved by selecting lower lumbar vessels, or with the use of preoperative computed tomographic angiography. Computed tomographic angiography can successfully identify the location, size, and course of lumbar artery perforators and can aid flap design. Lumbar artery perforators are highly useful for both donor and recipient vessels in free flap surgery.

The heel: anatomy, blood supply, and the pathophysiology of pressure ulcers.

There remains much confusion regarding the pathophysiology of pressure ulcers. Data indicate that the prevalence of pressure ulcers is increasing. The heel is unique in structure and well adapted to the task of shock absorption. However, it is often subject to prolonged pressure, which predisposes it to tissue breakdown, with attempts at reconstruction prone to failure. Four dissections were carried out of the heel region, which included removing each heel pad en bloc for histology. Seventeen arterial injection studies, 12 venous studies, and a combined arterial and venous study of the foot were performed. The results were correlated with clinical cases and previous research. The heel was found to be richly vascularized by a subdermal plexus and periosteal plexus with vessels traveling between the 2 within fibrous septa that connect the reticular dermis and periosteum of the calcaneus. These septa effectively create isolated compartments containing relatively avascular fat. A layer of panniculus carnosus muscle was observed in the subcutaneous tissue. It is likely that the metabolically active panniculus carnosus muscle is involved early in the course of pressure ulcers. Extensive pressure damage can be concealed by intact skin. Friction and shear are additional factors important in skin breakdown.

A novel approach to slow down putrefaction of unembalmed cadaveric tissue during lymphatic dissection: a preliminary study.

BACKGROUND: The putrefaction factor is one of the biggest problems when undertaking unembalmed cadaveric tissue dissections for lymphatic vessel mapping. METHODS: One female bilateral breast and anterior upper torso from an unembalmed human cadaver was studied over an 8-week period. Multiple prefrozen domestic ice bricks were used to cover in turn and keep constantly cold or partially frozen, the contralateral side of the tissue during the dissections. Using hydrogen peroxide to identify the lymphatics under the surgical microscope, the vessels were injected with a lead oxide mixture, and then radiographed to demonstrate lymphatic vessels in both breasts. The final results transferred to the computer for analysis. RESULTS: Lymph collecting vessels were found in breasts, anterior upper torso, and the internal mammary vascular bundles. The lymphatics of the breast and the anterior upper torso drain radially into the axillary lymph nodes. Unexpectedly, the lymphatic vessel drainage patterns of each breast are asymmetrical in this specimen. CONCLUSION: This study provides a new method to slow down putrefaction of unembalmed cadaveric tissue, thus enabling lymphatic dissection of a bilateral breast and torso specimen.

The arterial anatomy of the Achilles tendon: anatomical study and clinical implications.

The Achilles tendon is the most frequently ruptured tendon in the lower limb and accounts for almost 20% of all large tendon injuries. Despite numerous published studies describing its blood supply, there has been no uniformity in describing its topography. The current study comprises a detailed anatomical study of both the intrinsic and extrinsic arterial supply of the Achilles tendon, providing the detail sought from studies calling for improved planning of surgical procedures where damage to the vascularity of the Achilles tendon is likely. A dissection, microdissection, histological, and angiographic study was undertaken on 20 cadaveric lower limbs from 16 fresh and four embalmed cadavers. The Achilles tendon is supplied by two arteries, the posterior tibial and peroneal arteries. Three vascular territories were identified, with the midsection supplied by the peroneal artery, and the proximal and distal sections supplied by the posterior tibial artery. The midsection of the Achilles tendon was markedly more hypovascular that the rest of the tendon. The Achilles tendon is at highest risk of rupture and surgical complications at its midsection. Individuals with particularly poor supply of the midsection may be at increased risk of tendon rupture, and approaches to the tendon operatively should consider the route of supply by the peroneal artery to this susceptible part of the tendon.