共查询到20条相似文献,搜索用时 109 毫秒
1.
V P Misnik 《Arkhiv anatomii, gistologii i émbriologii》1979,77(7):34-39
In 50 right and 50 left upper extremities examined in adult persons of both sex at the age of 28-90 years, delto-thoracic lymph nodes were revealed in 30% (right) and in 22% (left), and interthoracic lymph nodes--in 6% (right) and in 12% (left). The lymph nodes in question were revealed by the method of section after interstitial injection of Gerota's blue intradermally to fingers, palm, back of the hand deltoid area, lateral thoracic surface (at the level of the 6th intercostal space) and to the external part of the mammary gland. Injection was also performed into lymphatic vessels revealed by means of the interstitial injection. The delto-thoracic nodes were stated to situate in both the delto-thoracic sulcus and the delto-thoracic triangle. These vessels are situated along the course of the lateral collector of the free upper extremity. Deferent vessels of the delto-thoracic nodes flow into the apical axillary lymph nodes, into the deep and superficial cervical nodes, into the interthoracic lymph nodes and also into the subclavicular or into the jugular vein near a corresponding venous angle. Interthoracic lymph nodes, situated between musculus pectoralis major and minor, get their lymphatic vessels from lateral, inferior and central axillary nodes, from delto-thoracic nodes and also those lymphatic vessels that go from the mammary gland area. Deferent vessels of the interthoracic nodes flow into the apical axillary nodes. 相似文献
2.
Algorithm for recipient vessel selection in free tissue transfer to the lower extremity. 总被引:3,自引:0,他引:3
The proper selection of a recipient vessel is essential for the success of free tissue transfer, especially when the transfer is to the lower extremity. However, a general agreement on which vessel to use has not been reached yet. Conflicting data have been reported on the survival and outcome of the transferred flaps, depending on the vessel used or the location of anastomosis. The aim of this study was to identify the patterns and problems in the selection of recipient vessels for free tissue transfer to the lower extremity and to establish a general guideline for proper selection. From September of 1990 to December of 1997, 50 consecutive, microvascular, free tissue transfers were performed on the lower extremity. The causes requiring soft-tissue coverage included trauma (25), unstable scar (11), chronic osteomyelitis (7), and tumors (7). The mean follow-up period was 22.4 months (range, 2 to 41 months). In 25 cases, the posterior tibial vessel was used as the recipient vessel. The microvascular anastomosis was done proximal to the zone of injury in 45 cases. The two most important factors in the selection of a recipient vessel are the site of injury and the vascular status of the lower extremity. Less important factors include the flap to be used, method, and site of microvascular anastomosis. All the currently feasible options for recipient vessels are included, and the opinions of other surgeons are reviewed. A general guideline is established, and an algorithm for the proper selection of a recipient vessel is proposed. This algorithm is a fast and convenient guide for evaluating the wound and planning the free flap to the lower extremity. 相似文献
3.
E V Shvetsov 《Arkhiv anatomii, gistologii i émbriologii》1991,100(7-8):50-57
The investigation of the external iliac lymph nodes has been performed in 152 preparations of corpses of mature persons of both sex, who died from causes not connected with any disease of the lymphatic system, lower extremities and pelvic organs. The external iliac lymph nodes and their afferent and efferent lymphatic vessels have been revealed by means of interstitial injection of the lower extremities and pelvic organs, as well as by means of direct injection of Gerota mass into the lymphatic vessels. Form, amount, dimensions and topography of common iliac lymph nodes have been studied. Lymphatic vessels, running from certain parts and organs of the body to various subgroups of the external iliac lymph nodes have been described, as well as efferent lymph vessels of these nodes. The external iliac lymph nodes are constant formations; the largest of them--lymph nodes of the lacuna--are nodes of the I step for the lower extremity lymph vessels. In 54% of cases in persons of both sex positive (right-sided) asymmetry has been revealed. Total amount of the iliac lymph nodes prevails in men, while their size is greater in women. The size of these nodes in persons of both sex is greater to the left than to the right. There are connections (in 3% of cases) between the external iliac lymph nodes and aortal and lumbar nodes of the opposite side. 相似文献
4.
64排螺旋CT下肢血管成像技术与DSA评估动脉狭窄的效果对比研究 总被引:1,自引:0,他引:1
目的探讨64排螺旋CTA评估下肢动脉狭窄闭塞性疾病的效果。方法对43例下肢动脉闭塞性疾病患者行64排螺旋CTA扫描,18例一周后行双下肢DSA检查,将每侧下肢血管分成8段,动脉狭窄程度分为:正常、轻度狭窄、中度狭窄、重度狭窄、闭塞5个级别。并以DSA为标准来评估。结果对18例患者双侧下肢共288段血管进行研究,CTA与DSA对血管狭窄程度显示一致的有275段,被CTA高估有ll段血管,低估有2段血管。结论64排螺旋CTA是下肢动脉狭窄硬化性疾病可靠的评估方法。 相似文献
5.
The tumescent technique has been shown to be efficacious in reducing both operative and postoperative bleeding without significant deleterious side effects in suction lipectomy. In this study, the effects of the tumescent technique on postoperative complications in transverse rectus abdominis myocutaneous (TRAM) flap breast reconstruction are investigated. All women who underwent a TRAM flap breast reconstruction by the senior author (J.B.) at the Emory Clinic during the years 1990 to 1996 were pooled (n = 386). Any woman who had a preincision infiltration of 0.25% epinephrine-containing saline solution (>200 cc) around the donor site was included in the tumescent group (n = 59). Medical records were reviewed, and rates of partial flap loss, fat necrosis (> or =10 percent flap volume), flap full-thickness skin loss, donor-site complication (skin loss, hernia, or infection), and blood transfusion were determined. Group rates were compared. The infiltrated group had a significantly lower transfusion rate as compared with the control group (0.34 units versus 1.32 units, p < 0.001). The rates of partial flap loss and fat necrosis were less in the tumescent group, but not significantly (0 percent versus 4 percent, p = 0.232; and 1.7 percent versus 10.4 percent, p = 0.058). There were no significant differences in the incidence of full-thickness skin loss or donor-site complications. Donor-site infiltration before incision with a 0.25% epinephrine-containing saline solution significantly reduced the transfusion requirement in TRAM flap breast reconstruction patients without adversely affecting either breast mound or abdominal donor-site complication rates. 相似文献
6.
Lymphatic mapping and sentinel lymph node biopsy in patients with melanoma of the lower extremity 总被引:3,自引:0,他引:3
Pu LL Cruse CW Wells KE Cantor A Glass LF Messina JL Reintgen DS 《Plastic and reconstructive surgery》1999,104(4):964-969
Lymphatic mapping and sentinel lymph node biopsy is a new technique used in the surgical treatment of patients with malignant melanoma. The purpose of this study was to evaluate the results of this approach for patients with melanoma of the lower extremity. Between May of 1994 and June of 1997 at the H. Lee Moffitt Cancer Center and Research Institute, 85 consecutive patients with clinical stage I and II melanoma of the lower extremity underwent lymphatic mapping and sentinel lymph node biopsy. These nodes were identified in all 85 patients by intraoperative lymphatic mapping with both radiolymphoscintigraphy and a vital blue dye injection. Eleven patients (12.9 percent) had histologically positive sentinel lymph nodes, and 10 patients underwent inguinal complete lymph node dissections. All 10 patients had no further histologically positive lymph nodes confirmed by subsequent complete dissection. Among 74 patients with histologically negative sentinel lymph nodes, only 2 patients (2.7 percent) developed inguinal nodal metastases during a mean follow-up period of 21.8 months (range, 13.5 to 58.3 months). The sensitivity of lymphatic mapping and sentinel lymph node biopsy in this series was 100 percent and the specificity was 97.3 percent. Therefore, we conclude that the use of lymphatic mapping and sentinel lymph node biopsy can accurately stage patients with melanoma of the lower extremity and provide a rational surgical approach for these patients. 相似文献
7.
200例下肢静脉造影分析 总被引:2,自引:0,他引:2
目的 分析下肢静脉疾病的分类,造影表现及造影对下肢静脉疾病的诊断价值。方法 对200例疑有下肢静脉疾病的患者进行常规或数字减影下肢静脉造影,根据造影表现进行分析。结果 200例307侧肢体下肢静脉造影结果:交通静脉瓣膜功能不全116侧肢体(37.8%),深静脉瓣膜功能不全39侧(12.7%),静脉阻塞性疾病85侧(27.7%),静脉瘤样病变6侧(1.9%),阴性61侧(19.9%);其中60岁以上老年患者124例197侧肢体中:静脉阻塞性疾病75侧(38.1%),交通静脉瓣膜功能不全69侧(35%),深静脉瓣膜功能不全21侧(10.7%),静脉瘤样病变3侧(1.5%),阴性29侧(14.7%)。结论 本组病例下肢静脉疾病中以静脉阻塞性疾病的比例较高(27.7%)与老年患者比例较高有关,其造影表现为各种治疗措施的选择提供可靠的依据。 相似文献
8.
The study of anatomical variants of lymphatic vessels connecting inguinal lymph nodes was carried out on 56 corpses of adult persons of both sex whose deaths were not connected with lesions in the lymphatic system of the pelvis and lower extremities. The inguinal lymph nodes and their afferent and efferent lymphatic vessels were detected by the method of intradermal injection and by the method of direct injection into the lymphatic vessels. It was stated that groups of the inguinal lymph nodes, as well as the nodes in every group determined, can serve as nodes of different stages for afferent lymphatic vessels running from different parts of the body and organs. 相似文献
9.
Lymphatic drainage in patients after replantation of extremities 总被引:1,自引:0,他引:1
Lymph drainage was studied by means of lymph scintigraphy in eight patients in whom successful replantation of a totally or subtotally amputated extremity had been performed. Scintigrams were made after subcutaneous injection of technetium-99m in the replanted part of the patient and the contralateral, normal extremity. In all scintigrams, axillary or inguinal lymph node activity is seen, implying drainage of lymph by means of the lymph vessels. Retention of colloid in the replanted part (79 to 94 percent) shows no significant difference with the contralateral, normal side (86 to 94 percent). Unquestionable evidence of regeneration of lymphatics in humans is delivered in the three patients, in whom lymph node activity and normal retention percentages are seen on the scintigrams after total amputation of an extremity followed by replantation without anastomosing of interrupted lymph vessels. 相似文献
10.
L Cárdenas-Camarena A Tobar-Losada A M Lacouture 《Plastic and reconstructive surgery》1999,104(6):1887-1899
During a 4-year period, 152 female and 9 male patients underwent large-volume liposuction, with ages ranging from 19 to 65 years (mean of 36 years), with a weight previous to surgery between 57 and 126 kg (mean of 72 kg). Tumescent liposuction was done simultaneously by two surgeons in several corporal areas according to the necessities of each case. In 28 patients (17 percent), 500 ml of whole blood was required previous to the surgery by self donation. By means of liposuction, volumes between 5 and 22.3 liters (mean of 8.7 liters) were obtained with an average relation of 860 cc of fat for 140 cc of liquid. The reduction of hemoglobin and hematocrit at 1 week after surgery was of 3.8 g and 12 percent, respectively. The weight after surgery during the patient's follow-up varied from 54 to 111 kg, with an average of 66 kg. Major complications were not presented. Minor complications consisted of two superficial cutaneous necroses (1.2 percent) and 18 seromas (11.2 percent), which were drained without leaving sequelae; 24 patients (14.9 percent) presented postsurgical palpable irregularities, visible in only 8 patients (5 percent); 148 patients (92 percent) expressed important satisfaction with the results of the surgery, with the remaining 13 (8 percent) expressing some disagreement due to persistent irregularities. These complications had a direct relationship to some factors of the surgical technique and some characteristics of the patients. The amount of fat liposuctioned, the ideal height-weight relationship of the patient, the diameter of the cannulas used, and the experience acquired during the time were the most important factors that were associated with the complications. Based on these results, we concluded that large-volume circumferential liposuction with tumescent technique is a viable and sure alternative to achieve improvement of the body contour and weight loss. 相似文献
11.
Rubin JP Bierman C Rosow CE Arthur GR Chang Y Courtiss EH May JW 《Plastic and reconstructive surgery》1999,103(3):990-6; discussion 997-1002
Injection of lidocaine into the subcutaneous tissues by the tumescent technique results in a delayed absorption of the local anesthetic and has allowed clinicians to exceed the maximum recommended dose of lidocaine without reported complications. However, little knowledge exists about the mechanisms that permit such high doses of lidocaine to be used safely with this technique. The presence of low concentration epinephrine and the increased tissue pressure resulting from the tumescent injection have both been implicated as important factors, but neither has been studied in patients whose results were not altered by the variability of the suction procedure. The purpose of this work was to determine the effect of tissue pressure during tumescent injection and presence of low concentration epinephrine on the absorption of lidocaine from subcutaneous tissues in human volunteers. Twenty healthy female human volunteers were randomized into four study groups. After body fat measurements, all subjects received an injection of 7 mg/kg of lidocaine into the subcutaneous tissues of both lateral thighs. The injected solution consisted of 0.1% lidocaine and 12.5 meq/liter sodium bicarbonate in normal saline with or without 1:1,000,000 epinephrine. Tissue pressure was recorded during injection using a specially designed double-barreled needle. The time required for injection was also recorded. Subjects in group 1 received lidocaine with epinephrine injected by a high-pressure technique. Group 2 subjects received lidocaine with epinephrine injected by a low-pressure technique. Group 3 subjects received lidocaine without epinephrine injected under high pressure. Group 4 subjects received lidocaine without epinephrine injected under low pressure. Following injection, sequential blood samples were drawn over a 14-hour period, and plasma lidocaine concentrations were determined by gas chromatography. No suction lipectomy was performed. Maximum tissue pressure during injection was 339 +/- 63 mmHg and 27 +/- 9 mmHg using high- and low-pressure techniques, respectively. Addition of 1:1,000,000 epinephrine, regardless of the pressure of injected fluid, significantly delayed the time to peak plasma concentration by over 7 hours. There was no significant difference in the peak plasma concentration of lidocaine among the four groups. Peak plasma concentrations greater than 1 mcg/ml were seen in 11 subjects. Epinephrine (1:1,000,000) significantly delays the absorption of lidocaine administered by the tumescent technique. High pressure generated in the subcutaneous tissues during injection of the solution does not affect lidocaine absorption. The delay in absorption may allow time for some lidocaine to be removed from the tissues by suction lipectomy. In addition, the slow rise to peak lidocaine concentration in the epinephrine groups may allow the development of systemic tolerance to high lidocaine plasma levels. 相似文献
12.
A V Kurkin B K Idrisov E A Nadyrov S V Lokhvitski? 《Arkhiv anatomii, gistologii i émbriologii》1991,101(9-10):18-20
The general structure and cell composition of the inguinal lymph nodes has been analysed at a direct endolymphatic antibiotic therapy, performed with the aim of prophylaxis of suppurative complications, when surgical interventions are performed in the vessels of the lower extremities. Morphokinetics of the lymph nodes depends on duration of the endolymphatic therapy. During early terms it reflects an increase in transport function of the regional inguinal lymph nodes, during late terms it reflects an increase in their immune role. In the lymph nodes, situating on the contralateral side, an analogous reaction is revealed; this appears to demonstrate presence of well developed collaterals between lymph vessels of the lower extremities. 相似文献
13.
External ultrasonic lipoplasty: an effective method of fat removal and skin shrinkage 总被引:15,自引:0,他引:15
External ultrasonic lipoplasty is an effective method for the removal of localized fat and the fat due to moderate obesity. The ultrasound is externally applied and transmitted through the skin surface. The acoustic waves are selectively absorbed by previously injected tumescent fluid and fat. It is the combination of this acoustic wave and ultrasound-induced fluid streaming that facilitates fat removal. Multiple, 2.5- to 3.7-mm incisions are made, through which standard thin (2.3 to 3.5 mm) suction lipectomy cannulae are used to aspirate the emulsified fat and oil. A major advantage of this procedure is that superficial subdermal liposuction can be used safely, which enhances the thoroughness of fat removal and the contraction of the overlying skin. A total of 160 consecutive patients successfully underwent this procedure. Recovery was rapid, and patients returned to full activities within 24 to 48 hours. The skin remained soft, with minimal to no bruising throughout the entire postoperative period. The problems seen with internal ultrasonic liposuction, such as end hits and skin burns, were avoided. The large incisions required for internal ultrasound liposuction were not necessary. Previous models of externally applied ultrasound support current observations of the safety of external ultrasound lipoplasty. Only one small seroma was seen. External ultrasound lipoplasty is a safe, effective, and low-cost method of ultrasound-assisted removal of localized fat and the fat due to moderate obesity. Physician and patient satisfaction is high. 相似文献
14.
LYVE-1, a new homologue of the CD44 glycoprotein, is a lymph-specific receptor for hyaluronan 总被引:76,自引:0,他引:76
Banerji S Ni J Wang SX Clasper S Su J Tammi R Jones M Jackson DG 《The Journal of cell biology》1999,144(4):789-801
The extracellular matrix glycosaminoglycan hyaluronan (HA) is an abundant component of skin and mesenchymal tissues where it facilitates cell migration during wound healing, inflammation, and embryonic morphogenesis. Both during normal tissue homeostasis and particularly after tissue injury, HA is mobilized from these sites through lymphatic vessels to the lymph nodes where it is degraded before entering the circulation for rapid uptake by the liver. Currently, however, the identities of HA binding molecules which control this pathway are unknown. Here we describe the first such molecule, LYVE-1, which we have identified as a major receptor for HA on the lymph vessel wall. The deduced amino acid sequence of LYVE-1 predicts a 322-residue type I integral membrane polypeptide 41% similar to the CD44 HA receptor with a 212-residue extracellular domain containing a single Link module the prototypic HA binding domain of the Link protein superfamily. Like CD44, the LYVE-1 molecule binds both soluble and immobilized HA. However, unlike CD44, the LYVE-1 molecule colocalizes with HA on the luminal face of the lymph vessel wall and is completely absent from blood vessels. Hence, LYVE-1 is the first lymph-specific HA receptor to be characterized and is a uniquely powerful marker for lymph vessels themselves. 相似文献
15.
Mounzer R Shkarin P Papademetris X Constable T Ruddle NH Fahmy TM 《Lymphatic research and biology》2007,5(3):151-158
BACKGROUND: Evaluation of lymphedema and lymph node metastasis in humans has relied primarily on invasive or radioactive modalities. While noninvasive technologies such as magnetic resonance imaging (MRI) offer the potential for true three-dimensional imaging of lymphatic structures, invasive modalities, such as optical fluorescence microscopy, provide higher resolution and clearer delineation of both lymph nodes and lymphatic vessels. Thus, contrast agents that image lymphatic vessels and lymph nodes by both fluorescence and MRI may further enhance our understanding of the structure and function of the lymphatic system. Recent applications of bimodal (fluorescence and MR) contrast agents in mice have not achieved clear visualization of lymphatic vessels and nodes. Here the authors describe the development of a nanoparticulate contrast agent that is taken up by lymphatic vessels to draining lymph nodes and detected by both modalities. METHODS: A unique nanoparticulate contrast agent composed of a polyamidoamine dendrimer core conjugated to paramagnetic contrast agents and fluorescent probes was synthesized. Anesthetized mice were injected with the nanoparticulates in the hind footpads and imaged by MR and fluorescence microscopy. High resolution MR and fluorescence images were obtained and compared to traditional techniques for lymphatic visualization using Evans blue dye. RESULTS: Lymph nodes and lymphatic vessels were clearly observed by both MRI and fluorescence microscopy using the bimodal nanoparticulate contrast agent. Characteristic tail-lymphatics were also visualized by both modalities. Contrast imaging yielded a higher resolution than the traditional method employing Evans blue dye. MR data correlated with fluorescence and Evans blue dye imaging. CONCLUSION: A bimodal nanoparticulate contrast agent facilitates the visualization of lymphatic vessels and lymph nodes by both fluorescence microscopy and MRI with strong correlation between the two modalities. This agent may translate to applications such as the assessment of malignancy and lymphedema in humans and the evaluation of lymphatic vessel function and morphology in animal models. 相似文献
16.
V P Misnik 《Arkhiv anatomii, gistologii i émbriologii》1975,69(7):40-45
The anatomy and topography of the right and left axillary nodes were studied by the method of polychrome injections in 25 corpses of adult people dead from trauma or illnesses not related to lesions of axillary lymph nodes. Injections were made into the skin of fingers, palm and back of the hand, in the delta-shaped area, lateral surface of the chest and exterior half of the mamillary gland and also immediately into the lymph vessels of the upper extremity found with the help of interstitial injections. Detailed data on the topography of axillary lymph nodes relative to the walls, blood vessels and nerves of the axillary fossa were obtained, and the relations between the nodes were specified. From the topography of the axillary lymph nodes under study and approaching the lymph vessels as well as from literature data it is expedient to divide the axillary lymph nodes into 6 groups: lateral, medial, posterior, inferior, central and apical. 相似文献
17.
Hägerling R Pollmann C Kremer L Andresen V Kiefer F 《Biochemical Society transactions》2011,39(6):1674-1681
Lymphatic vessels, the second vascular system of higher vertebrates, are indispensable for fluid tissue homoeostasis, dietary fat resorption and immune surveillance. Not only are lymphatic vessels formed during fetal development, when the lymphatic endothelium differentiates and separates from blood endothelial cells, but also lymphangiogenesis occurs during adult life under conditions of inflammation, wound healing and tumour formation. Under all of these conditions, haemopoietic cells can exert instructive influences on lymph vessel growth and are essential for the vital separation of blood and lymphatic vessels. LECs (lymphatic endothelial cells) are characterized by expression of a number of unique genes that distinguish them from blood endothelium and can be utilized to drive reporter genes in a lymph endothelial-specific fashion. In the present paper, we describe the Prox1 (prospero homeobox protein 1) promoter-driven expression of the fluorescent protein mOrange2, which allows the specific intravital visualization of lymph vessel growth and behaviour during mouse fetal development and in adult mice. 相似文献
18.
Miles G. Johnston Andrew Kanalec John L. Gordon 《Prostaglandins & other lipid mediators》1983,25(1):85-98
Lymphatic vessels exhibit rhythmical contractility and and this activity appears ti regulate lymph flow. A technique for measuring the cicurlar muscle contractions of isolated bovine mesenteric lymphatic vessel segments has been devised and utilized to study the pharmacological properties of these vessels. Non-contracting lympahtic vessels can be induced to contract rhythmically with a variety of mediators, the most potent being a stable PGH2 analogue (compound U46619), and the leukotrienes B4, C4 and D4 (threshold concentrations in the nanomolar range). Prostagladin F2α, noradrenaline, serotonin and histamine also elicited rhythmical activity but much higher concentrations were required. PGE2 and PGE1 were potent inhibitors of spontaneous contractions or those induced with U46619. In keeping with the diverse pharmacological effects of the metabolites of arachidonic acid, the addition of arachidonate to an isolated lymphatic vessel generated both stimulatory and inhibitory activities.It is concluded that arachidonic acid products (produced in the lymphatic vessel or entering the vessel in lymph draining the tissues) regulate lymph flow through their effects on lymphatic smooth muscle. 相似文献
19.
Richard R. Uwiera Rabban Mangat Sandra Kelly Trina C. Uwiera Spencer D. Proctor 《Journal of visualized experiments : JoVE》2016,(109)
Catheterization of the intestinal lymph trunk in neonatal pigs is a technique allowing for the long-term collection of large quantities of intestinal (central) efferent lymph. Importantly, the collection of central lymph from the intestine enables researchers to study both the mechanisms and lipid constitutes associated with lipid metabolism, intestinal inflammation and cancer metastasis, as well as cells involved in immune function and immunosurveillance. A ventral mid-line surgical approach permits excellent surgical exposure to the cranial abdomen and relatively easy access to the intestinal lymph trunk vessel that lies near the pancreas and the right ventral segment of the portal vein underneath the visceral aspect of the right liver lobe. The vessel is meticulously dissected and released from the surrounding fascia and then dilated with sutures allowing for insertion and subsequent securing of the catheter into the vessel. The catheter is exteriorized and approximately 1 L/24 hr of lymph is collected over a 7 day period. While this technique enables the collection of large quantities of central lymph over an extended period of time, the success depends on careful surgical dissection, tissue handling and close attention to proper surgical technique. This is particularly important with surgeries in young animals as the lymph vessels can easily tear, potentially leading to surgical and experimental failure. The video demonstrates an excellent surgical technique for the collection of intestinal lymph. 相似文献
20.
Ny A Koch M Schneider M Neven E Tong RT Maity S Fischer C Plaisance S Lambrechts D Héligon C Terclavers S Ciesiolka M Kälin R Man WY Senn I Wyns S Lupu F Brändli A Vleminckx K Collen D Dewerchin M Conway EM Moons L Jain RK Carmeliet P 《Nature medicine》2005,11(9):998-1004
Lymph vessels control fluid homeostasis, immunity and metastasis. Unraveling the molecular basis of lymphangiogenesis has been hampered by the lack of a small animal model that can be genetically manipulated. Here, we show that Xenopus tadpoles develop lymph vessels from lymphangioblasts or, through transdifferentiation, from venous endothelial cells. Lymphangiography showed that these lymph vessels drain lymph, through the lymph heart, to the venous circulation. Morpholino-mediated knockdown of the lymphangiogenic factor Prox1 caused lymph vessel defects and lymphedema by impairing lymphatic commitment. Knockdown of vascular endothelial growth factor C (VEGF-C) also induced lymph vessel defects and lymphedema, but primarily by affecting migration of lymphatic endothelial cells. Knockdown of VEGF-C also resulted in aberrant blood vessel formation in tadpoles. This tadpole model offers opportunities for the discovery of new regulators of lymphangiogenesis. 相似文献