A novel method for long-lasting preservation of arterial grafts.

BACKGROUND: Autologous venous grafts generally give best results for arterial bypass grafting in cases of arterial stenosis. When no suitable venous graft can be found, synthetic prosthetic graft may be an alternative. Prostheses are easily accessible but susceptible to infection. In these cases, the replacement of infected prosthesis by the human arterial allograft is the best treatment option. The question arises whether we could prepare a graft meeting mechanical conditions of an artery immunologically inert and resistant to bacterial infection. MATERIALS AND METHODS: LEW and BN rat aortic segments were placed in dehydrated sodium chloride and stored for 1 to 12 mo. Then, they were transplanted orthotopically as aortic grafts for 3 to 15 mo in syngenic and allogenic combination. No immunosuppression was used. Patency, pulsation, and frequency of development of aneurysms were studied. The tensile strength and maximum intraluminal pressures were measured. Morphology of grafts was evaluated on histology and electron microscopy. The endothelial and infiltrating cells were identified. RESULTS: Transplanted allogeneic aortic grafts preserved in anhydrous sodium chloride up to 12 mo remained patent for 15 mo. Hypertrophy of intima with endothelial cells lining the inner surface and single muscle cells between elastic fibers were seen. Normal structure of collagen and elastic fibers was maintained. Only minor-host mononuclear infiltrates were seen around the preserved allografts. CONCLUSIONS: Rat aortas preserved in anhydrous sodium chloride retain patency and function even 15 mo after transplantation. Such grafts retain their wall structure and evoke only minor recipient reaction. Our results confirm that anhydrous sodium chloride may be used for arterial grafts preservation. Low immunogenicity is additional advantage.

LDL and HDL transfer rates across peripheral microvascular endothelium agree with those predicted for passive ultrafiltration in humans.

The mechanisms by which LDLs and HDLs cross the vascular endothelium from plasma into interstitial fluid are not understood, and have never been studied in humans in vivo. We determined whether the plasma-to-lymph clearance rates of LDL and HDL conform with those predicted by passive ultrafiltration through intercellular pores, or if it is necessary to invoke an active process such as receptor-mediated transcytosis. Plasma and afferent peripheral lymph were collected under steady-state conditions from 30 healthy men, and assayed for seven globular proteins of molecular radii 2.89-8.95 nm, complement C3, and apo AI, apo AII, and apo B. Plasma-to-lymph clearance rates of the seven proteins fitted the relation expected for molecules of their size when transported through two populations of pores of radius 4.95 and 20.1 nm. The same model parameters were then found to accurately predict the clearance rates of both HDL and LDL. The apparent clearance of complement C3, previously shown to be secreted by cultured endothelium, exceeded that predicted by the model. We conclude that the transport of HDL and LDL from plasma into interstitial fluid across the peripheral vascular endothelium in healthy humans can be explained by ultrafiltration without invoking an additional active process such as transcytosis.

IL-6 regulates adipose deposition and homeostasis in lymphedema.

Lymphedema (LE) is a morbid disease characterized by chronic limb swelling and adipose deposition. Although it is clear that lymphatic injury is necessary for this pathology, the mechanisms that underlie lymphedema remain unknown. IL-6 is a known regulator of adipose homeostasis in obesity and has been shown to be increased in primary and secondary models of lymphedema. Therefore, the purpose of this study was to determine the role of IL-6 in adipose deposition in lymphedema. The expression of IL-6 was analyzed in clinical tissue specimens and serum from patients with or without LE, as well as in two mouse models of lymphatic injury. In addition, we analyzed IL-6 expression/adipose deposition in mice deficient in CD4(+) cells (CD4KO) or IL-6 expression (IL-6KO) or mice treated with a small molecule inhibitor of IL-6 or CD4 depleting antibodies to determine how IL-6 expression is regulated and the effect of changes in IL-6 expression on adipose deposition after lymphatic injury. Patients with LE and mice treated with lymphatic excision of the tail had significantly elevated tissue and serum expression of IL-6 and its downstream mediator. The expression of IL-6 was associated with adipose deposition and CD4(+) inflammation and was markedly decreased in CD4KO mice. Loss of IL-6 function resulted in significantly increased adipose deposition after tail lymphatic injury. Our findings suggest that IL-6 is increased as a result of adipose deposition and CD4(+) cell inflammation in lymphedema. In addition, our study suggests that IL-6 expression in lymphedema acts to limit adipose accumulation.

Lipoprotein remodeling generates lipid-poor apolipoprotein A-I particles in human interstitial fluid.

Although much is known about the remodeling of high density lipoproteins (HDLs) in blood, there is no information on that in interstitial fluid, where it might have a major impact on the transport of cholesterol from cells. We incubated plasma and afferent (prenodal) peripheral lymph from 10 healthy men at 37°C in vitro and followed the changes in HDL subclasses by nondenaturing two-dimensional crossed immunoelectrophoresis and size-exclusion chromatography. In plasma, there was always initially a net conversion of small pre-ß-HDLs to cholesteryl ester (CE)-rich α-HDLs. By contrast, in lymph, there was only net production of pre-ß-HDLs from α-HDLs. Endogenous cholesterol esterification rate, cholesteryl ester transfer protein (CETP) concentration, CE transfer activity, phospholipid transfer protein (PLTP) concentration, and phospholipid transfer activity in lymph averaged 5.0, 10.4, 8.2, 25.0, and 82.0% of those in plasma, respectively (all P < 0.02). Lymph PLTP concentration, but not phospholipid transfer activity, was positively correlated with that in plasma (r = +0.63, P = 0.05). Mean PLTP-specific activity was 3.5-fold greater in lymph, reflecting a greater proportion of the high-activity form of PLTP. These findings suggest that cholesterol esterification rate and PLTP specific activity are differentially regulated in the two matrices in accordance with the requirements of reverse cholesterol transport, generating lipid-poor pre-ß-HDLs in the extracellular matrix for cholesterol uptake from neighboring cells and converting pre-ß-HDLs to α-HDLs in plasma for the delivery of cell-derived CEs to the liver.

Cancer seeding contributes to intestinal anastomotic dehiscence.

BACKGROUND: Surgical wounds in cancer patients have a relatively high dehiscence rate. Although colon cancer resections are performed so as to include macroscopically non-involved tissues, some cancer cells can be present in the line of transection. The local healing process may facilitate proliferation of these localized cancer cells and the high cytokine concentration within the healing wound may also attract cancer cells from distant sites to migrate into the wound area. The growing tumor cells may then stretch the wound, hampering its contraction process. METHODS: The aim of the study was to monitor and compare, using immunohistochemical methods, the healing process of intestinal anastomosis in both normal rats and in rats with disseminated cancer (the CC531 colon cancer model). RESULTS: There was a significantly higher rate of anastomotic dehiscence in the group of rats with disseminated cancer, than in the group of normal rats. There were no significant differences between the two groups in the levels of mononuclear wound infiltration or of formation of connective tissue or new vessels. All anastomotic wounds in animals with disseminated cancer had abundant infiltrates of both migrating and proliferating cancer cells. CONCLUSIONS: We confirmed that the environment of a healing wound attracts cancer cells. Migration of cancer cells to the wound and centrifugal cancer proliferation may adversely affect the healing process and cause wound disruption.

Lower Limb Lipedema-Superficial Lymph Flow, Skin Water Concentration, Skin and Subcutaneous Tissue Elasticity.

Background: Lipedema of lower limbs is characterized by bilateral accumulations of excess adipose tissue starting from the ankle to the hips and buttocks. The studies with lymphoscintigraphy (LSC) and magnetic resonance (MR) lymphography show altered transport index and enlarged lymphatic vessels (LVs). Our studies aimed to investigate the superficial lymph flow, water accumulation, skin and subcutaneous tissue elasticity, and the possibility of using this information to diagnose lipedema. Methods and Results: Fifty patients with lipedema and 50 control subjects (women) were included. The Indocyanine Green (ICG) lymphography, LSC, skin water measurement, skin durometry, and deep tissue tonometry were done in all participants. ICG lymphography revealed: (1) Slower lymph flow in lipedema patients; after 3 minutes of feet movement in a horizontal position, the ICG-dyed lymph reached the upper calf level in 8% of lipedema patients compared with 56% in the control group (p ˂ 0.0001). (2) More than three LVs were noticed more often in lipedema patients. (3) The higher number of abnormal LV images at all limb levels and during each observation stage with a statistically significant number of foggy and dilated. (4) Statistically significant higher fluorescent intensity in all limb levels. Skin water concentration was higher in the feet in lipedema (p = 0.000189). Conclusion: Our studies have shown the differences in superficial lymph flow and water concentration between lipedema and normal limbs. Data proove the usefulness of ICG lymphography, skin water concentration and skin and subcutaneous tissue elasticity measurements in diagnosing lipedema.

Simulation-based reasoning of residual tissue deformations in a two-chamber test of a lymphedematous leg.

A two-chamber inflation-deflation test was recently proposed as a diagnostic method to determine parameters of the intermittent pneumatic compression used as an effective therapeutic modality for lymphedematous limbs. It is crucial that the recorded trends for residual tissue deformations are understood in terms of specific properties of subcutaneous tissue and skin to support diagnostic process. This paper presents a mechanical model of lymphedematous legs in two-chamber tests. The cylindrical geometry composed of layers of skin, modeled as hyperelastic medium, and subcutaneous tissue, modeled as fluid saturated hyperporoelastic medium, is assumed. The results of finite element simulations show the possibility of such combinations of the properties of skin (rigidity) and subcutaneous tissue (rigidity and permeability), which ensures that the model predictions resemble the evolution of tissue residual deformations observed in the two-chamber test. The stiffness and permeability appeared to be the most crucial tissue property determining trend lines of residual deformations. The analysis of the components of displacement of solid matrix and pore fluid pressure explains the mechanisms that are responsible for particular tissue behavior. The moderate role of skin and limitations related to the mechanical and geometrical model assumptions are indicated. Recommendations for treating lymphedema using intermittent compression therapy in relation to the results of the two-chamber test and properties of tissues are discussed.

Secretion of adipokines by human adipose tissue in vivo: partitioning between capillary and lymphatic transport.

Peptides secreted by adipose tissue (adipokines) may enter blood via capillaries or lymph. The relative importance of these pathways for a given adipokine might influence its biological effects. Because this has not been studied in any species, we measured the concentrations of seven adipokines and eight nonsecreted proteins in afferent peripheral lymph and venous plasma from 12 healthy men. Data for nonsecreted proteins were used to derive indices of microvascular permeability, which in conjunction with the molecular radii of the adipokines were used to estimate the amounts leaving the tissue via capillaries. Transport rates via lymph were estimated from the lymph adipokine concentrations and lymph flow rates and total transport (secretion) as the sum of this and capillary transport. Concentrations of nonsecreted proteins were always lower in lymph than in plasma. With the exception of adiponectin, adipokine concentrations were always higher in lymph (P < 0.01). Leptin and MCP-1 were secreted at the highest rates (means: 43 µg/h or 2.7 nmol/h and 32 µg/h or 2.4 nmol/h, respectively). IL-6 and MCP-1 secretion rates varied greatly between subjects. The proportion of an adipokine transported via lymph was directly related to its molecular radius (r(s) = +0.94, P = 0.025, n = 6), increasing from 14 to 100% as the radius increased from 1.18 (IL-8) to 3.24 nm (TNFα). We conclude that the lymph/capillary partitioning of adipokines is a function of molecular size, which may affect both their regional and systemic effects in vivo. This finding may have implications for the physiology of peptides secreted by other tissues.

Lack of effect of the CD14 promoter gene C-159T polymorphism on nutritional status parameters in hemodialysis patients.

BACKGROUND: CD14 is a membrane glycoprotein that acts as a co-receptor for the detection of bacterial lipopolysaccharide (LPS). Mutual interaction between CD14 and LPS plays an important role in the innate immune system. Increased serum soluble CD14 levels have been described in hemodialysis (HD) patients, and linked to increased mortality risk, inflammation and protein-energy wasting. The expression of CD14 may be influenced by CD14 promoter gene C-159T polymorphism. This study aimed to clarify the possible association between CD14 promoter gene C-159T polymorphism and nutritional status in hemodialysis patients. MATERIAL/METHODS: The study population consisted of 185 (104 males; 81 females) long-term HD patients treated in 5 dialysis centers. The control group consisted of 112 apparently healthy volunteers (32 males and 80 females). Nutritional status was assessed using a modified SGA scale, and anthropometric methods (BMI, WHR, waist, hip and mid-arm circumferences, biceps, triceps, subocular and subscapular skinfolds). Biochemical parameters evaluated included: CRP, albumin, creatinine, urea, cholesterol, triglycerides and TIBC. CD14 promoter gene C-159T polymorphism was determined by restriction fragment length polymorphism, after digestion of the PCR product with Hae III restriction endonuclease. RESULTS: Genotype and allele frequencies were similar to controls and compliant with Hardy-Weinberg equilibrium. No between-group differences were detected in measured variables with the exception of lower triglyceride levels in carriers of C allele in comparison to TT genotype. CONCLUSIONS: CD14 promoter gene C-159T polymorphism does not seem to be associated with nutritional status parameters in HD patients. It does seem, however, to influence triglyceride blood levels.

Genetic factors responsible for long bone fractures non-union.

INTRODUCTION: Approximately 10-15% of all fractures of long bones heal with delay, prolonged immobilization and repetitive operative interventions. Despite intense investigations, the pathomechanism of impaired healing of skeletal tissue remains unclear. An important role in the pathomechanism of mal-union of close fractures plays subclinically proceeding infections. AIM: The question arises whether colonization and proliferation of bacteria in the fracture gap could be related to the mutation of genes for factors regulating local antimicrobial response, such as pathogen recognizing receptors (PRR), cytokines and chemokines. METHODS: We carried out studies in patients with delayed long bone fractures estimating the frequency of mutation of genes crucial for pathogen recognition (TLR2, TLR4 and CD14), and elimination (CRP, IL-6, IL-1ra), as well as wound healing (TGF-ß). The molecular milieu regulating healing process (IGF-1, COLL1a, TGF-ß, BMP-2, and PDGF) was validated by Western blot analysis of the gap tissue. RESULTS: Microbiological investigations showed the presence of viable bacterial strains in 34 out of 108 gaps in patients with non-healing fractures (31.5%) and in 20 out of 122 patients with uneventful healing (16.4%) (P < 0.05). The occurrence of mutated TLR4 1/W but not 2/W gene was significantly higher (P < 0.05) in the non-healing infected than sterile group. In the non-healing infected group 1/W mutated gene frequency was also higher than in healing infected. In the TGF-ß codon 10 a significantly higher frequency of mutated homozygote T and heterozygote C/T in the non-healing infected versus non-healing sterile subgroup was observed (P < 0.05). Similar difference was observed in the non-healing infected versus healing infected subgroup (P < 0.05). The CRP (G1059C), IL1ra (genotype 2/2), IL-6 (G176C), CD14 (G-159T), TLR2 (G2259A) and TLR4/2 (Thr399Ile) polymorphisms did not play evident role in the delay of fracture healing. CONCLUSIONS: Individuals bearing the mutant TLR 4 gene 1/W (Asp299Gly) and TGF-ß gene codon 10 mutant T and T/C allele may predispose to impaired pathogen recognition and elimination, leading to prolonged pathogen existence in the fracture gaps and healing delays.

Long-Term Benzathine Penicillin Prophylaxis Lasting for Years Effectively Prevents Recurrence of Dermato-Lymphangio-Adenitis (Cellulitis) in Limb Lymphedema.

Background: The lymphedema-affected limbs are predisposed to acute and, subsequently, chronic dermato-lymphangio-adenitis (DLA) episodes in around 40%-50% of cases, irrespective of what the primary etiological factor is for the development of this condition. DLA is of bacterial etiology, and it needs antibiotic control and prevention of recurrence. Our aim was to follow the effects of years-long continuous no-break administration of benzathine penicillin on the recurrence of acute DLA episodes. Methods and Results: Two hundred thirty-one patients were affected with lymphedema of lower and upper limbs. The mean duration of lymphedema was 10.2 ± 7.3 (range 2-30) years, and the number of DLA attacks/patient was 3.3 ± 3.2 (range 1-10). The total number of DLA episodes was 805. Benzathine penicillin injections 1,200,000 units were given i.m. at 14-21 days intervals (mean 18 ± 9 days) with short accidental breaks only. The period of therapy was 39.2 ± 38.7 (median 32) months. Recurrence occurred in 23 out of 231 (10%) (p < 0.01). There were 42 DLA incidents compared with 805 before introduction of therapy (5.2%) patients (hazard ratio 0.05, 95% confidence interval 0.034-0.079) (p < 0.01). Among patients with recurrence, there was a decrease of DLA episodes from 6.2% ± 3.6% to 1.7% ± 1.0%/patient. There were no differences in effectiveness of penicillin prophylaxis between etiological groups, depending on stages of lymphedema. Conclusions: Long-term years-long benzathine penicillin prophylaxis is extremely effective in prevention of DLA recurrence. It can be applied for years with no breaks, without clinical side-effects, and raising resistance to antibiotics. Microbial colonization and evoked inflammatory reaction of hosts should be controlled from the first symptoms of lymph stasis, irrespective of the etiology of lymphedema.

Estimation of hydromechanical parameters of limb lymphedematous tissue with the use of chamber tests.

PURPOSE: In this paper, in vivo methods of estimation of the shear modulus and hydraulic permeability of subcutaneous tissue of lower limb are presented. METHODS: The experimental technique is based on single- or two-chamber inflation-deflation tests in which temporal changes in limb circumference under the test chamber for cyclic loading are registered. Simplified models for fast undrained deformation and slow creep of oedematous tissue with squeezing out interstitial liquid were considered. Finite element simulations of the chamber test within a finite deformation poroelastic model were elaborated. RESULTS: Formulas necessary to estimate the shear modulus and permeability of subcutaneous tissue were derived and then tested or calibrated using the results of poroelastic simulations. An example of application of the derived formulas for clinical data obtained from the chamber test was discussed. CONCLUSIONS: A simple in vivo methods of estimation of the hydromechanical properties of lymphedematous tissue (shear modulus and permeability) were proposed. The strengths and weaknesses of the proposed methodology were discussed.

Tissue Structure and Edema Fluid Events During Treatment of Lymphedema of Limbs with a Manual Pressure-Calibrated Device, Linforoll.

Background: Linforoll is a device composed of handpiece with roller and pressure sensor connected wireless to the computer displaying the pressure curve of the applied force. In a previous study, we proved it to regulate the applied force according to the hydromechanic conditions of the massaged tissues. Standardization of massage based on applied force was repeatable in the same patient; it decreased limb volume and provided evident increase in tissue elasticity. Methods and Results: In this study, we measured additional parameters useful for the understanding of tissue and fluid events and approval of the device for general practice. These were skin stiffness, subcutaneous tissue stiffness independent of skin, skin water concentration, changes in skin temperature, skin capillary blood flow, subcutaneous tissue fluid pressure, volume of the moved edema fluid, and visualization of movement on indocyanine green (ICG) lymphography. Measurements were done before and during the massage. The data were obtained from a group of 20 patients with obstructive lymphedema of lower limbs during the Linforoll massage. There was a lack of significant changes in skin stiffness, skin water concentration, skin surface temperature, and capillary blood flow, but evident increase in the subcutaneous tissue elasticity (tonometry) and lymphography-shown flow of the edema fluid. Conclusions: The skin tissue hydromechanic parameters remained normal proving lack of destructive changes under high massaging pressures. The obtained data evidently show that not the skin but the subcutis accumulated edema fluid that can successfully be moved proximally under pressures of 80-120 mmHg.

The Neglected Leg Lymphatic Vascular Changes in the Pathomechanism of Delayed Onset Muscle Soreness in Runners.

Background: Delayed onset muscle soreness (DOMS) in runners is classified as a leg muscle strain injury and presents with tenderness or stiffness to palpation and movement limitation. Most attention is directed at muscles but not at the mass of other limb soft tissues, including their lymphatic vasculature, although they undergo mechanical stress and bruises, edema, nail destruction, and pains contributing to symptoms. Methods and Results: The study was done on lower limbs of long-distance runners suffering from DOMS complaints. There were 16 runners, 11 males and 5 females, age 22-28, practicing long-distance running over the last 5 years, with body mass index (BMI) 23 ± 4. Inclusion criteria: three to five marathon runs per year and daily 3-5 km slow runs. Last long distance run 3 to 7 days before the investigation. Controls were six subjects initiating running, of the same age group and BMI. Testing of blood and lymph flow was done before and after standard ergometer 300 W 30 minutes cycling. The measurement methods were leg and big toe venous plethysmography, big toe capillary Doppler, tonometry of skin and deep tissues, lymphoscintigraphy, and indocyanine green (ICG) fluorescent lymphography. (a) Strain gauge plethysmography of the calf and big toe revealed a two- to three-times higher venous capacity in runners than in controls, (b) the increased toe venous capacity was confirmed by point Doppler recordings showing two- to three-times higher blood capillary flow compared to controls, (c) lymphoscintigraphy revealed retention of tracer in feet, dilated superficial and deep lymphatics, and enlarged popliteal and inguinal lymph nodes, and (d) ICG lymphograms showed confluents of accumulated fluid in foot and calf subcutaneous tissue with fluorescence level reaching 40%-50% compared to 20% in controls. Conclusion: Our results show that, 3-5 days after run, not only muscles but also skin and subcutaneous tissue reveal major tissue fluid accumulation, an overload bringing about functional lymphatic transport insufficiency. This may be an additional factor responsible for DOMS symptoms.

The Effectiveness of Intermittent Pneumatic Compression in Therapy of Lymphedema of Lower Limbs: Methods of Evaluation and Results.

BACKGROUND: Evaluation of intermittent pneumatic compression (IPC) in lymphedema is classically based on measurements of circumferences and volume of the edematous limb. However, although important, it provides only a general information without insight into what proceeds under the skin with respect to hydromechanical and structural changes. AIM AND METHODS: We present the multimodal evaluation of the effectiveness of IPC device in limb edema by measuring tissue stiffness, fluid pressure, and flow volume, and lymphoscintigraphic and near-infrared fluorescence (NIRF) indocyanine green (ICG) lymphography imaging of edema fluid movement, before and after one 45-60 minute compression cycle in over 50 patients with lymphedema stage II and III. RESULTS: (1) Tissue fluid pressures were lower than those applied by IPC device. (2) The higher the applied compression force, the larger the flow volume. (3) Skin stiffness (superficial tonometry) decreased mainly in the calf, whereas, subcutaneous tissue (deep tonometry) was observed at all limb levels. (4) Skin water concentration (dielectric constant) was only insignificantly decreased, but subcutaneous extracellular water (bioimpedance Ldex index, fluid movement force test) was effectively moved away to limb proximal regions. (5) Imaging tissue (edema) fluid flow pathways on lymphoscintigram and real-time flow on NIRF ICG video could be observed and were evaluated semiquantitatively. CONCLUSIONS: Adjustment of compression parameters to tissue stiffness, fluid accumulation volumes, and fluid movement ability (hydraulic conductivity of tissues) at various limb levels is indispensable for effective therapy. Redesigning of compression devices will be needed to enable applying differentiated compression pressures and prolonged timings at various limb levels.

The long-term arterial assist intermittent pneumatic compression generating venous flow obstruction is responsible for improvement of arterial flow in ischemic legs.

BACKGROUND: There is a large group of patients with ischemia of lower limbs not suitable for surgical reconstruction of arteries treated with the help of external assist by intermittent pneumatic compression devices (IPC). Until recently the generally accepted notion was that by compressing tissues below the knee, veins become emptied, venous pressure drops to zero and the increased arterial-venous pressure gradient enables greater arterial flow. We used a pump that, in contradiction to the "empty veins" devices, limited the limb venous outflow by venous obstructions and in a long period therapy expanded the perfusion vessels and brought about persistent reactive hyperemia. AIM: To check the toe and calf arterial inflow measured by venous stasis plethysmography and capillary flow velocity during arterial assist IPC in a long-term therapy of ischemic legs. MATERIAL AND METHODS: Eighteen patients (12M, 6F) age 62 to 75 with leg peripheral arterial disease (PAD, Fontaine stage II) were studied. Pneumatic device with two 10cm wide cuffs (foot, calf) (Bio Compression Systems, Moonachie, NJ, USA) inflated to 120 mmHg for 5-6 sec to obstruct the venous flow, deflation time 16 sec, applied for 45-60 min daily for a period of 2 years. RESULTS: At pump inflation increase in toe arterial pressure, volume, capillary blood flow velocity and one-minute arterial inflow test was observed. Increased toe volume appeared concomitantly with the inflated chamber venous obstruction. Resting pressure in the great saphenous vein increased. The two years therapy showed persistence of the resting limb increased toe capillary flow. Intermittent claudication distance increased by 20-120%. After two years arterial assist TBI increased from 0.2 to 0.6 (range 0.3 to 0.8) (p<0.05 vs pre-therapy). The toe arterial inflow dominated over that in calf skin and muscles, nevertheless, there was prolongation of the claudication distance presumably due to dilatation of exchange vessels also in muscles. CONCLUSIONS: Our arterial assist IPC brought about increase in the toe capillary flow, long lasting dilatation of toe capillaries and extension of painless walking distance. The crucial factor of rhythmic repeated venous outflow obstructions should be taken into account in designing effective assist devices.

Edema Fluid Can Be Successfully Evacuated from the Lymphedematous Limbs by Implantation of Silicone Tubings Bypassing the Site of Flow Obstruction Long-Term Observations.

Background: Lymphedema of limbs is caused by partial or total obstruction of lymphatic collectors. In advanced cases all main lymphatics are obstructed and tissue fluid accumulates in the interstitial spaces. The microsurgical lympho-venous shunts cannot be performed. We propose in such cases drainage of fluid accumulations by creating artificial flow pathways to the nonobstructed regions by implantation of silicone tubes. Aim: To present the 3 to over 6 year follow-up results of therapy by subcutaneous implantation of silicone tubes. Methods: In 150 patients with obstructive limb lymphedema after pelvic or axillary lymphadenectomy and irradiation in uterine or breast cancer or following soft tissue inflammation silicone tubes were implanted subcutaneously. Results: There was (1) immediate decrease of limb circumference within days after implantation; (2) in lower limbs in a 3-year follow-up a decrease in mid-calf circumference by a mean -8.7% (p < 0.05) with range of -3.2% to -31.0% corresponding to 90-900 mL volume and in the mid-thigh a mean -1.8% (p < 0.05) with range of -9.3% to +3% equal to 0-900 mL. In the upper limb in the 2-year follow-up the decrease in the mid-forearm was -8.5% (p < 0.01) with a range of -3.0% to -22.0% and in the mid-arm a mean -12% (p < 0.05) with a range of -7% to -22%. That corresponded to 180-700 mL volume for the limb; (3) decreased tissue stiffness; (4) maintenance of tubes patency on control lymphoscintigraphy, contrast opacification, and ultrasonography; and (5) lack of reaction to foreign body and effective control of inflammation at the site of implantation using low doses of benzathine penicillin. Conclusions: The technical simplicity of the surgical procedure, fast decrease of limb edema, and lack of tissue reaction to the implant make the method worth applying in advanced stages of lymphedema.

Contractility patterns of human leg lymphatics in various stages of obstructive lymphedema.

In healthy human leg, lymphatics contract spontaneously, rhythmically propelling lymph. The pressures generated by lymphatic contractions constitute the main force for lymph flow. This mechanism is of utmost importance during night rest, anesthesia, and immobilization, as well as in those with damaged peripheral motor neurons. Under physiological conditions, limb muscular activity and position only slightly change lymph flow. In obstructive lymphedema, lymphatic wall muscular fibers become damaged and the spontaneous contractility becomes ineffective in lymph transport because of low generated pressures and lymphatic valve insufficiency. The lymph-propelling task is taken over by leg muscle contractions. Measuring intralymphatic pressures and flow gives some insight into the mechanism of lymph flow in healthy limbs and loss of this function in lymphedema. This knowledge will be useful in the derivation of rational treatments for lymphedema.

Bacteriology of callus of closed fractures of tibia and femur.

BACKGROUND: More than 1% of closed fractures of lower limbs and 6% of orthopedic implants are complicated by inflammation caused by infection despite of all precautionary methods taken. The question arises whether this clinical complication is not caused by bacteria dwelling in limb tissues. METHODS: Skin, subcutaneous fat, muscle, and fracture gap callus were obtained from 71 adult patients operated on due to closed fractures of tibia or femur; 28 because of comminuted fractures and mal-alignment of bone axis with nonoperative means, and 43 due to delayed healing and unstable union. RESULTS: Aerobic bacteria were isolated from gap callus of 14% healing and 35% nonhealing fractures. No isolates were found in subcutis and only in 3% in muscles. No anaerobic bacteria were detected. Polymerase chain reaction amplifications of 16S rRNA were found positive in 42% of callus specimens proving presence of bacterial DNA even when no isolates were found. The 95% similarity of the genetic pattern of some strains from foot skin and callus, estimated with random amplification of polymorphic DNA technique, suggested their foot skin origin. CONCLUSIONS: The colonizing bacterial cells and their DNA were detected in fracture callus but not in other deep tissues. Contamination was precluded by lack of isolates in disinfected cutis, subcutis, muscles, and materials used for sampling cultured after surgery. We suggest that certain strains of bacteria dwell in normal tissues of lower limbs and may cause inflammation upon stimulation by trauma. Their source may be tissue fluid, superficial and deep lymphatics, and lymph serving the physiologic transport to the regional lymph nodes of microorganisms penetrating foot skin during microinjuries.

Indocyanine green near-infrared lymphangiography for evaluation of effectiveness of edema fluid flow under therapeutic compression.

The commonly used modalities for therapy of limb lymphedema are manual lymphatic drainage, manual devices moving edema fluid and intermittent pneumatic compression (IPC). What seems to be necessary for validation of the effect of the compression procedure is imaging of the mobilized moving edema fluid. Picture of edema fluid flow would allow the therapist to use force adjusted to the tissue volume and stiffness differing in various limb regions as well as identify sites of abundant accumulation of fluid requiring more compression. The purpose of the present study was to visualize tissue edema fluid flow during manual drainage, Linforoll massage, IPC and bandaging. To obtain data how high compression pressures should be used to mobilize indocyanine green (ICG)-stained fluid, concomitantly tissue fluid pressure measurements were performed. The following observations were obtained: (1) the possibility of real-time observation of edema fluid movement using various compression modalities, (2) the threshold pressures necessary to move edema fluid to be over 80 mm Hg in the compression device and over 40 mm Hg in the tissue fluid and (3) inefficacy of compression in some cases despite applying high compression force. These observations point to the need of ICG lymphangiography before compression therapy in each patient. The images observed during the compression procedure give an insight into the distribution of edema fluid, sites of its accumulation and efficacy of applied external force on fluid mobilization.