Femoral Vein Ligation Research Articles

Vein Crossover Bypass Surgery for a Chronic Femoral Vein Ligation -A case report-

A twenty six year old man was admitted to our clinic for bleeding from a venous ulcer of the left leg. His left femoral vein had been ligated for bleeding control after a traffic accident that happened when he was 5 years old. He had a varicose vein, stasis dermatitis, and a venous ulcer on his left leg. To shunt left femoral venous return to the right femoral vein, we did a crossover bypass with arteriovenous fistula using the right greater saphenous vein. To get good patency of the arteriovenous fistula, the bypass graft was closed 6 weeks after the initial operation. He maintained his left leg circumference relatively well for 6 months after the operation. We report the case of a patient who had a vein crossover bypass for a chronic femoral vein ligation.

O efeito da sulfadiazina de prata, extrato de ipê-roxo e extrato de barbatimão na cicatrização de feridas cutâneas em ratos

Morphological study of effects of silver sulfadiazine, Tabebuia avellanedae (ipê-roxo) extract and Stryphnodendron adstringens (barbatimão) extract on cutaneous wound healing was done. Ninety six Wistar rats were used. All animals underwent a femoral right vein ligation to induce a venous hypertension. Thirty days after the cutaneous wound was done, they were divided into groups of four animals. Group S received silver sulfadiazine topical application; group IR, Tabebuia avellanedae extract topical application; group B received Stryphnodendron adstringens extract topical application and group C received physiological solution topical application, every day for a period of seven, 14 and 30 days. Histology analyzed the presence vascular proliferation, neutrophil and lymphocite, fibroblast, collagen fiber and epithelization. The macroscopic analysis showed complete epithelization at 14 days in group S, IR e B. The histological data at 14 days of observation only group C still showed incomplete epithelization in six animals. At the same period there was a statistic significant difference between the control group and the others groups as inflammation process and neovascularization. About the presence fibroblasts and collagen, there was statistic significant difference between the control group and the others groups at the 30 days because at this period the control group still showed fibroblasts and collagen lower when compared to the others groups. The morphological analysis of the results permits to infer that the group S, IR and B had a better healing of skin wounds, when compared with the control.

Anatomic location of penetrating lower-extremity trauma predicts compartment syndrome development

Background Compartment syndrome of the lower extremity can be a difficult diagnosis to make with serious consequences if diagnosis and intervention is delayed. Identifying patients who are more likely to develop this syndrome can help prevent the associated complications. The purpose of this study was to evaluate whether the anatomic location of the penetrating lower-extremity injuries can predict development of compartment syndrome. Methods A retrospective chart review was performed of all patients admitted for a minimum of 23 hours to the University of South Alabama trauma center for penetrating lower-extremity trauma during the 8-year period from July 1998 through June 2006. Patients were entered in the study if wound trajectory was confined to the lower extremity between the inguinal ligament and the ankle. Injuries were categorized as above knee (AK) or below knee (BK), and whether the injury was in the proximal or distal half of the extremity segment. Clinical examination or compartmental pressures were used to diagnose BK compartment syndrome. Results A total of 321 patients sustained 393 lower-extremity injuries during the study period, of which 255 (65%) were AK and 138 (35%) were BK. Thirty-one (8%) lower extremities developed BK compartment syndrome with 29 (94%) secondary to penetrating injuries of the BK segment. All BK injuries that developed compartment syndrome were located in the proximal half of the BK segment. Eighteen (7%) AK injuries underwent BK 4-compartment fasciotomy, 16 (6%) of which were prophylactic after surgical intervention for AK vascular injury. Two patients (1%) developed postoperative BK compartment syndrome after superficial femoral vein ligation. All AK injuries that underwent fasciotomy sustained vascular injuries requiring surgical intervention. No BK compartment syndromes occurred in any patients with expectantly managed AK or distal BK injuries. Conclusions Injuries to the proximal half of the BK segment are the most common cause for the development of compartment syndrome from penetrating injuries of the lower extremity. Development of BK compartment syndrome because of penetrating AK injury is rare without an associated surgically significant vascular injury. Observational admission for compartment syndrome development in patients with penetrating injury to the AK segment or distal BK segment is unnecessary.

Surgical treatment of profunda femoral vein insufficiency

To study the role and curative effect of encircling construction of the popliteal vein and ligation of the profunda femoral vein (PFV) to treat profunda femoral vein insufficiency (PFVI). Thirty-four patients were diagnosed as having PFVI through phlebography and color ultrasound system. (CEAP clinical scale: C(4) 31, C(5) 1, C(6) 2). The forms of the profunda femoral veins (PFV) were Raju grouping, type II: 22, type III: 10, type IV: 2. Thirty-two patients' popliteal veins were annularly constructed in the distal communication of the PFV and the popliteal vein, and in the abouchement of gastrocnemius vein into the popliteal vein. The other two PFV trunks were ligated at the communication of PFV trunk and the popliteal vein. Thirty-one patients (91.1%), 4, 6-year follow-up in average, threw off their aching pain in the leg. Pigmentation from the ankle to the middle of the leg subsided; the ulcers were healed and did not relapse. The postoperative ambulatory venous pressure detected was distinguishable from the preoperative data (P < 0.01), venous pressure recovery time > 22 seconds. A standing position (60 degrees from the vertical) is used in the postoperative phlebography. And the development time of the contrast media reaching the superior margin of patellar level, together with the regurgitation volume per minute of the popliteal vein detected through color ultrasound system in a standing position, was recorded. The patients' physical status had been greatly improved after the surgery (P < 0.01). The back flow caused by PFVI has a deep impact on the hemodynamics of the lower limb. In the popliteal fossa, it is operable and effective to use encircling construction of popliteal vein and the ligation of the PFV to treat PFVI.

Pressure gradients and transport in the murine femur upon hindlimb suspension

Interstitial fluid flow (IFF) is important in a number of processes, including stimulation of cells and nutrient and waste transport. In bone, it arises from the vascular pressure gradient between the medullary cavity and the lymphatic drainage at the periosteal surface and is enhanced by mechanical loading events. However, little is known about the pressure gradients experienced by bone cells in vivo and the role of the induced IFF in bone adaptation. This study investigated IFF changes in bone, in a disuse model and in ambulatory mice, from pressure gradients measured by telemetry, and by fluorescent tracers. The role of IFF-mediated transport of oxygen was assessed by the levels of hypoxic osteocytes in mouse femur after disuse by hindlimb suspension and with or without femoral vein ligation. Femoral intramedullary pressures in alert mice decreased to 77% upon hindlimb suspension and increased by 25% upon ligation, relative to baseline. To determine relative perfusion of cortical bone by IFF, the localization of intracardiac-injected fluorescent albumin conjugate with osteocytes was monitored. The number of osteocytic lacunae per bone area positive for Texas Red albumin was increased by 31% within 20–40 s, in the ligated femur compared to the contralateral sham femur. This confirmed that interstitial fluid flow was increased by femoral vein ligation and indicated that the increase was proportional to the pressure increase. Unloaded bone osteocytes were not hypoxic when compared to loaded controls and venous ligation did not alter these levels significantly. These results support the hypothesis that disuse by hindlimb suspension leads to decreased pressure gradients, which indicate lower IFF. Similarly, the increased pressure gradients, seen upon venous ligation, increased IFF from marrow to periosteum. While a decrease in intramedullary pressure in disuse suggests a decrease in IFF, this did not lead to hypoxia in osteocytes. We conclude that decreased oxygen convective transport in the mouse hindlimb disuse model does not account for cortical bone loss. This study is important in increasing our understanding of the mechanotransductory pathways involved in bone loading and unloading.

Venous ligation-mediated bone adaptation is NOS 3 dependent

Interstitial fluid flow (IFF) in bone has been hypothesized to mediate bone modeling in the absence of mechanical strain. The mechanism of this effect has not been clearly defined, though previous studies indicate that nitric oxide (NO) may play an important role in mediating IFF. In the current study, mice with a targeted disruption of the NOS 3 gene were used according to a previously established model of altered interstitial fluid flow in bone. Femoral vein ligation was performed in one limb to increase intramedullary pressure and consequently its IFF; a sham operation was performed on the contralateral limb. The mice were then hindlimb suspended to uncouple the effects of altered flow in the limb from mechanical loading. Differences in radiographic bone density and bone strength were compared for the sham and venous-ligated femurs in wild-type (WT) mice and NOS 3 knockout (KO) mice. Suspension-induced bone loss in the femurs, as evidenced by a loss in radiographic bone mineral density (BMD), was seen in both groups. Differences between sham and venous-ligated femurs were significant only for the WT mice, in which there appeared to be a protective effect of venous ligation against bone loss [−6.69% (ligated) vs. −12.36% (sham), P < 0.05]. Furthermore, the difference in bone density between sham and venous-ligated femurs was muted by NOS 3 knockout, suggesting that the protective effect of venous ligation against bone loss observed in the WT group was NO dependent. The differences in relative BMD were mirrored in the mechanical testing experiments, where maximum load to fracture was significantly higher in the venous-ligated limbs relative to the sham limbs of the WT mice, but not in the NOS 3 group. Taken together, these data further support the hypothesis that fluid flow can modulate bone modeling and suggest that IFF-mediated bone adaptation is NOS 3 dependent.

Thrombolysis for experimental deep venous thrombosis maintains valvular competence and vasoreactivity

Purpose: Thrombolysis protects the structural and functional integrity of vein wall in an experimental model of acute deep venous thrombosis (DVT) immediately after treatment, but late sequelae have not been studied. We designed experiments to compare the effects of thrombolysis and surgical thrombectomy at 4 weeks after the treatment of DVT.Methods: DVT was produced bilaterally in male mongrel dogs by proximal and distal femoral vein ligation. Five dogs underwent sham operation. After 48 hours, the ligatures were removed, and the thrombosis was treated with either Fogarty balloon catheter thrombectomy (shear force, 60 g; n = 6) or catheter-directed urokinase infusion (4000 U/min for 90 minutes; n = 6). At 4 weeks, patency and valvular competence were determined by duplex ultrasound scanning. Thrombogenicity was studied by the measurement of radiolabeled fibrin and platelet deposition. Veins were explanted and prepared for histologic examination, scanning electron microscopy, and functional studies in organ chambers.Results: All veins were patent at 1 month. Recanalized thrombus was observed histologically in four (66%) thrombectomized veins, one (17%) thrombolyzed vein, and none of the sham-operated veins (P = .04). Scanning electron microscopy demonstrated similar luminal endothelial cell loss (11%–25%) in all three groups. Platelet and fibrin depositions were not different among groups. Valvular incompetence (reflux duration, >0.5 sec) did not differ significantly in the groups (thrombectomized veins, 2 of 12 (17%); thrombolyzed veins, 0 of 12 (0%); P = NS). In organ chamber studies, endothelium-dependent relaxations to calcium ionophore, but not adenosine diphosphate, were inhibited by an antagonist of nitric oxide production after thrombectomy (P < .05, thrombectomy vs sham- and thrombolysis-treated veins). All veins relaxed to exogenous nitric oxide.Conclusion: Both thrombectomy and thrombolysis restored patency and achieved similar valvular competence. Surgical thrombectomy, however, resulted in more residual thrombus and contributed to changes in endothelium-mediated relaxations at 4 weeks. Thrombolysis maintained both structural integrity and endothelial function.

Femoral vein ligation increases bone mass in the hindlimb suspended rat

Bone remodeling in response to changing mechanical demands is well recognized. It has been hypothesized that alterations in interstitial fluid flow (IFF), due to intraosseous pressure changes, influence bone remodeling. The goal of this study was to investigate the role of IFF in bone in the absence of mechanical strain using an in vivo model, the hindlimb suspended rat. Bone remodeling was assessed by direct measurements of weight, dimensions, bone mineral content (BMC) and bone mineral density (BMD) by dual-energy X-ray absorptiometry (DEXA), and trabecular density using peripheral computed tomography (pQCT). Ligation of one femoral vein was performed as a means to alter the IFF within the ipsilateral femur; the contralateral limb was sham-operated as control. Animals were suspended for a period of 19 days. Intramedullary pressure in the venous-ligated femurs increased relative to the sham-operated control femurs (27.8 mmHg vs. 16.4 mmHg, p < 0.05), suggesting venous ligation increased IFF proportional to the pressure drop across the bone. Bone mineral content (BMC), when normalized to body weight, increased significantly in the venous-ligated femurs relative to control limbs (115.9 ± 15.6% vs. 103.8 ± 13.2%, p < 0.001); similarly, gains in length (106.2 ± 2.4% vs. 104.5 ± 2.1%, p < 0.05) and distal width (110.8 ± 10.3% vs. 106.2 ± 8.2%, p < 0.05) for the femurs with venous ligation were significantly greater relative to sham control. Furthermore, trabecular density was significantly higher in the femurs with venous ligation (351 ± 12 g/cm3 vs. 329 ± 11 g/cm3, p < 0.05). Daily administration of the cyclooxygenase inhibitor, indomethacin, via drinking water, suppressed the length increases observed for the venous ligated femur, suggesting a role for prostaglandins in IFF-mediated remodeling. These results suggest that IFF can directly influence bone adaptation independent of mechanical loading, and supports the hypothesis that fluid flow modulates bone remodeling.

Ultrastructure of Evolving Deep Venous Collaterals

Objective: To explore the structure of obstructive venous collaterals. Design: A total of 25 rats underwent unilateral ligation of the distal common femoral vein. Bilateral (control and test) vein segments with collaterals were harvested and studied with conventional light microscopy and electron microscopy at 2-week intervals for 10 weeks post-ligation. Results: Obstructive collaterals were quite unlike normal controls throughout the study. Initially, post-obstructive collateral walls showed disorganization of collagen, elastin, smooth muscle cells, and adventitia, while endothelial cells became more rounded and compact. The dense protein subendothelial deposits noted early became organized and moved more deeply into the wall at subsequent study intervals. Minimal motivation of smooth muscle cells, coalescence of elastic lamina, condensation of collagen and some organization of the wall were noted. Conclusion: Inability of deep collaterals to function with normal wall properties is likely to be secondary to the disruption of connective tissue and sustained disorganization of the vein wall noted throughout the evolution of collateral formation.

Increased Lymphoscintigraphic Flow Pattern in the Lower Extremity Under Evaluation for Lymphedema

To analyze the clinical and scintigraphic features in four postoperative patients with lower limb edema. Four case reports are presented, and causes of increased lymphatic flow are discussed. Filtered 99mTc-sulfur colloid (0.1 mL; 20 MBq) was administered by subcutaneous injection into the second web space of each foot. Sequential local (inguinal) and whole-body imaging was performed periodically up to 24 hours after the injections. The patients were three women who were 40, 51, and 86 years of age and an 81-year-old man. Each patient had unilateral lower extremity swelling and had recently undergone an ipsilateral lower limb operation. One female patient had previously undergone proximal femoral vein ligation, and another female patient had venous insufficiency demonstrated by Doppler ultrasonography. The male patient had a history of severe arterial insufficiency, and the remaining female patient had no venous or arterial abnormalities. On lymphoscintigraphy, all patients showed increased lymphatic flow in the edematous lower limb. Only the male patient also demonstrated abnormal dermal backflow pattern. Increased lymphatic flow most likely is a normal response to lower limb edema in the presence of normal peripheral lymphatic structures. In the four described cases, a recent lower limb surgical procedure may have resulted in disturbance of normal proximal lymphatic channels. The role of sympathetic innervation of the peripheral lymphatic system is a potential factor determining lymphatic response to trauma or surgical intervention. Increased flow on lymphoscintigraphy may not necessarily represent normal flow, especially if other scintigraphic features of abnormal lymphatic function-such as dermal backflow pattern-are present.

Carotid surgery: the past is prologue. The John Homans lecture.

Carotid surgery: the past is prologue. The John Homans lecture.

Infusion of Phospholipid Vesicles Amplifies the Local Thrombotic Response to TNF and Anti-Protein C into a Consumptive Response

Inflammation often is considered a contributing factor to both thrombosis and disseminated intravascular coagulation. The molecular mechanisms that dictate which of these clinical manifestations will result from the inflammatory stimulus remain obscure. Bacterial infection and certain tumors are common initiators of the disseminated intravascular coagulant response. Complement activation resulting from bacterial infection shares with selected tumors the capacity to generate or release membrane particles that lack functional adhesion receptors and hence could circulate to amplify a disseminated intravascular coagulant response. We developed a model of venous thrombosis that resulted in localized thrombus formation without disseminated intravascular coagulation. The model involves infusion of tumor necrosis factor, blockade of protein C and a partial decrease in venous flow caused by ligation of the superficial femoral vein without obstruction of the deep formal vein. Infusion of phospholipid vesicles into this model resulted in amplification of a localized thrombotic response into a consumptive response. Seven different groups of animals were studied. The first three groups established the conditions necessary to produce deep vein thrombosis. The second four groups established the conditions necessary to produce disseminated intravascular coagulation. The infusion of phospholipid vesicles plus tumor necrosis factor and anti-protein C antibody resulted in consumption of fibrinogen, the production of thrombin/antithrombin complexes, a fall in platelet count, and venous thrombosis. Without ligation and catheterization phospholipid vesicles failed to produce the consumptive response. We conclude, therefore, that phospholipid vesicles can amplify a local thrombotic response into a consumptive response, and that vesiculation accompanying inflammation is one means by which localized coagulant activity may be amplified to produce disseminated intravascular coagulation.

Energy metabolism and adenine nucleotide degradation in twitch-stimulated rat hindlimb during ischemia-reperfusion.

The purpose of this study was to characterize twitch tension and energy metabolism in ischemic, stimulated rat hindlimb to determine its suitability as a rapid time course model of ischemia-reperfusion injury. After 15 min equilibration, rat hindlimbs were stimulated (1-Hz twitches, 0.2 ms pulse duration, 15 V) for 5 min (control, n = 8). This twitch protocol was maintained throughout the ischemic and reperfusion periods. The control period was followed by 5, 20, or 40 min of ischemia (ligation of femoral artery and vein) or 40 min of ischemia with 0, 5, or 20 min of reperfusion (removal of ligature). The soleus [89% slow oxidative (SO)] and the white gastrocnemius [WG; 91% fast glycolytic (FG)] were analyzed for phosphocreatine (PCr), adenine nucleotides, glycogen, and glycolytic intermediates. Ischemia was characterized by progressive decreases in twitch tension, high-energy phosphagens, total adenine nucleotides (TAN), and glycogen. Also, energy metabolism was altered at a greater rate in WG than in soleus. Reperfusion resulted in a recovery in PCr and lactate, with little change in ATP, TAN, or glycogen. The inability to resynthesize adenine nucleotides and glycogen during reperfusion is characteristic of damaged skeletal muscle. The extent of the metabolic alterations in SO and FG muscles during twitch stimulation was comparable with previously reported noncontracting ischemia protocols of 2-4 and 4-7 h in length, respectively. The present study demonstrates that twitch stimulation of ischemic skeletal muscle is a useful model for inducing rapid metabolic changes and an ischemic insult comparable to prolonged noncontracting ischemia-reperfusion models.

Long-term effects of superficial femoral vein ligation: Thirteen-year follow-up

This study examines the late clinical, hemodynamic, and anatomic results of superficial femoral vein ligation performed in 35 extremities that were followed an average of 1312 years (range, 5 to 22 years). Indications for interruption were to prevent recurrent embolization from distal deep venous thrombosis (14 cases), to prevent emboli in patients with contraindication to anticoagulants (eight cases), to prevent distal reflux in selected patients undergoing iliofemoral thrombectomy (11 cases), and to control reflux in failed venous reconstruction (two cases). Ligation was effective in the prevention of pulmonary emboli as indicated by no significant clinical events and 15 negative postligation ventilation-perfusion scans. Long-term clinical follow-up showed normal (class 0) or near-normal (class 1) extremities in 83%. Fourteen percent developed mild to moderate symptoms of pain or swelling but without ulceration (class 2), and only one case (3%) had ulcerative sequelae (class 3). The only two findings that correlated with worse clinical outcome were the presence of an incompetent profunda femoris or an obstructed greater saphenous vein. Profunda femoris reflux was found in 60% (35) of patients with class 2 or 3 sequelae, which was significantly higher than the 14% (322) found in those patients with class 0 or 1 results (p < 0.05). Obstruction of the greater saphenous vein was found in 50% of those patients with class 2 or 3 results as opposed to 9% with class 0 or 1 results (p = 0.05). A large collateral vessel between the profunda femoris and the distal superficial femoral or popliteal vein was associated with poor long-term results. We could not identify a clear correlation between physiologic obstruction and the clinical state. These findings indicate that superficial femoral vein ligation is effective and can be used as an alternative treatment to prevent emboli arising from lower extremity deep venous thrombosis in cases of contraindication to or failure of anticoagulation. Superficial femoral vein obstruction appears to be well tolerated over the long-term when the profunda femoris is patent and competent or the greater saphenous vein is unobstructed.

Long-term effects of superficial femoral vein ligation: Thirteen-year follow-up

Long-term effects of superficial femoral vein ligation: Thirteen-year follow-up

The effect of venous flow alterations upon patency of rat femoral vein anastomoses.

The rat femoral vein has become a standard model for laboratory training in microvascular anastomotic technique as well as for research investigations into factors affecting venous patency. This study examined the short-term patency (1 and 7 days) of rat vein anastomoses. The influences upon patency of epigastric flap creation and distal femoral vessel ligation (epigastric flow only) were explored. In a separate experiment, blood flow from the femoral vein was determined through catheter collection of venous efflux; the influences of island epigastric flap creation and distal femoral ligation on flow rates were explored. It was found that 82% of basic femoral vein anastomoses were patent at one day, while 100% of anastomoses associated with an epigastric flap and ligated/transected distal femoral vessel circulation (creating a low-tension anastomosis) were patent (P less than 0.01). With distal femoral vessel ligation and no transection (normal tension at the repair), anastomoses were patent in 90% of the veins when an epigastric flap was also raised, and in 60% when a flap was not created. When a flap was raised without disturbing the distal femoral circulation, vein patency was 75% at one day. When the vein anastomosis was performed with distal femoral vein ligation, the patency rate was 50%. All veins patent at 1 day were also patent at 7 days post-op; 96% of veins clotted at 1 day were found to be patent at 7 days. The venous efflux was not found to vary significantly when an epigastric flap was raised.(ABSTRACT TRUNCATED AT 250 WORDS)

Venous blood flow in the leg after ligation of the femoral vein during cardiac catheterization in young children

In the period from 1963 to 1973, 143 heart catheterizations were carried out in children under two years of age. In 33 patients, the femoral vein was exposed by cutdown and ligated afterward. Ten of these patients (the other 23 having died in the intervening years) were available for follow-up and the venous outflow of the lower extremities was studied. Nine of the ten patients showed no abnormality, but one patient had developed varicose veins. In this patient, plethysmography showed reduced venous outflow, and phlebography showed narrowing of the common femoral vein at the site of earlier ligation, indicating recanalization. It is concluded that, if the femoral vein must be used, careful dissection is necessary to secure the bifurcation of the femoral vein and avoid ligation of the common femoral vein.

Management of symptomatic deep venous thrombosis and pulmonary embolism on a neurosurgical service.

The authors present a retrospective analysis of the management of deep vein thrombosis (DVT) and pulmonary embolism (PE) in neurosurgical patients at the Massachusetts General Hospital from January, 1978, through June, 1982. There were 44 cases of DVT and 13 cases of PE. Management modalities included observation only, femoral vein ligation, inferior vena cava clipping, transvenous placement of an inferior vena cava filter or umbrella, and anticoagulation therapy. Six (75%) of eight patients with symptomatic DVT who were managed by observation alone had subsequent pulmonary emboli, and three (38%) died. Femoral vein ligation was followed by PE in one of four cases and led to significant leg swelling in two others. Neither observation alone nor femoral vein ligation can be recommended as routine management options. Partial inferior vena cava interruption with a De Weese clip, Kim-Ray Greenfield filter, or Mobin-Uddin umbrella all successfully prevented pulmonary emboli. The major problem associated with these methods was leg edema, which occurred in 47% of patients with clip placement, 25% with filter placement, and 21% with a Mobin-Uddin umbrella. Anticoagulation therapy was associated with a complication rate of 29% and a mortality rate of 15%. Fatal PE and paradoxical hypercoagulability with gangrene of a lower extremity were the causes of death. In one patient, hemorrhage into a glioblastoma occurred following discontinuation of anticoagulation therapy when the coagulation parameters were normal. The authors conclude that: 1) management with observation alone of patients with symptomatic DVT places the patient at risk for the development of life-threatening pulmonary emboli; 2) the safety and timing of therapeutic anticoagulation in postoperative neurosurgical patients or patients with tumors is unclear; and 3) partial interruption of the inferior vena cava with a transvenous filter successfully prevents PE and may represent a safer alternative to anticoagulation therapy.

Interstitial compliance and transcapillary Starling pressures in cat skin and skeletal muscle.

Interstitial compliance, defined as change in local interstitial fluid volume (delta IFV) divided by the corresponding change in local interstitial fluid pressure (delta IFP), has been measured in skin and muscle of pentobarbital-anesthetized cats. IFP was measured with micropipettes and IFV as the difference between 51Cr-ethylenediaminetetraacetic acid space and 125I-human serum albumin space. IFV was altered by overhydration (saline infusion, 10% of body wt, or by femoral vein ligation plus saline infusion, 20% of body wt) or by dehydration (peritoneal dialysis with 20% glucose). Control IFV in skin and muscle averaged 1.45 (SD 0.44, n = 22) and 0.37 (SD 0.04, n = 22) ml/g dry wt, respectively, with corresponding IFP of -1.9 (SD 0.4, n = 22) and -0.8 (SD 0.6, n = 22) mmHg. During dehydration, IFV fell by 5.5 and 10.4% per mmHg fall in IFP in skin and muscle, respectively. The maximal rise in IFP during overhydration was about 2 mmHg in both tissues. Analysis of covariance showed that compliance was lower in cats than in rats during dehydration (P less than 0.05). At subnormal IFV, IFP will therefore be more powerful in opposing capillary absorption of interstitial fluid in cats than in rats. IFP is, however, of similar importance in edema prevention in the two species.

Amputation risk factors in concomitant superficial femoral artery and vein injuries.

Only a small subset of patients with combined superficial femoral artery and vein injuries results in amputation. The importance of the venous component as a risk factor for amputation is uncertain. Ligation vs. reconstruction of venous injuries is controversial. For clarification of these issues, we analyzed retrospectively multiple risk factors for amputation in combined superficial femoral artery and vein injuries in a civilian population. There were 25 patients treated in a 20-year period. Sixteen injuries were caused by small caliber missiles, six by shotgun blasts, and three by knife wounds. Three patients (12%) ultimately underwent amputation. The major risk factor for amputation was method of vascular reconstruction. All three amputations underwent ligation of the superficial femoral vein with arterial reconstruction by placement of a reversed interposition saphenous vein graft (p = 0.0009). None of the remaining 22 patients with salvaged limbs underwent reconstruction by this combination of techniques. Consequently, the authors emphasize the importance of venous reconstruction, particularly in combined injuries with major arterial involvement requiring interposed grafts.