Where does venous reflux start?

Purpose: This study was designed to identify the origin of lower limb primary venous reflux in asymptomatic young individuals and to compare patterns of reflux with age-matched subjects with prominent or clinically apparent varicose veins.Methods: Forty age- and sex-matched subjects with no symptoms (age, 15 to 35 years; 80 limbs; group A), 20 subjects (age, 19 to 32 years; 40 limbs) with prominent but nonvaricose veins (n = 26 limbs; group B), and 50 patients (age, 17 to 34 years; 100 limbs) with varicose veins (n = 64; group C) were examined with color flow duplex imaging. All proximal veins (above popliteal skin crease), superficial, perforator, and deep, in the lower limb were examined in the standing position, and all the distal veins in the sitting position. Patients who had a documented episode of superficial or deep vein thrombosis, previous venous surgery, or injection sclerotherapy were excluded from the study.Results: The prevalence of reflux in group A was 14% (11 of 80), in group B 77% (31 of 40), and in group C 87% (87 of 100). In more than 80% of limbs in the three groups, reflux was confined to the superficial veins alone. Deep venous reflux or combined patterns of reflux were uncommon even in group C. Reflux was detected in all segments of the saphenous veins and their tributaries. In the 125 limbs that had superficial venous incompetence, the below-knee segment of the greater saphenous vein was the most common site of reflux (85, 68%), followed by the above-knee segment of greater saphenous vein (69, 55%) and the saphenofemoral junction (41, 32%). Nonsaphenous reflux was rare (3, 2.4%). Reflux in the lesser saphenous vein (21, 17%) was seen in all groups, whereas involvement of both greater and lesser saphenous veins (8, 6.4%) was seen in group C alone. The incidence of multisegmental reflux was significantly higher in group C (61 of 64, 95%) than in group A (two of 11, 18%) or group B (14 of 26, 54%). The prevalence of distal reflux was comparable in all groups.Conclusions: Primary venous reflux can occur in any superficial or deep vein of the lower limbs. The below-knee veins are often involved in asymptomatic individuals and in those who have prominent or varicose veins. These data suggest that reflux appears to be a local or multifocal process in addition to or separate from a retrograde process. (J Vasc Surg 1997;26:736-42.)     

Does severe venous insufficiency have a different etiology in the morbidly obese? Is it venous?

OBJECTIVE: Chronic venous insufficiency (CVI) is the most common cause of leg ulcers. Patients with morbid obesity are remarkable for particularly recalcitrant ulcers. Because obesity is not specifically incorporated in CEAP or other venous scoring systems, we sought to characterize this group of patients more completely. METHODS: Patients with severe CVI (CEAP clinical class, 4, 5, and 6), and class III obesity (body mass index [BMI], >40) were reviewed. Findings from clinical and duplex ultrasound scan (DU) examinations were compared with the CEAP classification, its adjunctive venous clinical severity score, and sensory thresholds. RESULTS: A review of clinic records identified 20 ambulatory patients with a mean age of 62 years, a mean BMI of 52, and a mean weight of 164 kg (361 lbs); all but one had bilateral symptoms. No evidence of venous insufficiency was detected with DU in 24 of the 39 limbs. Although some valvular incompetence was detected with DU in 15 of 39 limbs, these abnormalities were widely dispersed between 28 sites; eight limbs had findings at only one site. Ulceration (mean area, 29 cm(2)) was present in 25 limbs and necessitated 7 months for healing; 13 (52%) recurred at least once during a mean observation period of 36 months. The mean sensory threshold of 5.21 exceeded current risk thresholds used in diabetic screening programs. The distribution of CEAP clinical class was C4 (n = 14), C5 (n = 14), and C6 (n = 11). Increasing CEAP class correlated with an increased mean BMI of 47, 52, and 56, respectively (P <.01). CEAP also correlated with a rising mean venous clinical severity score of 10, 11, and 15, respectively (P <.05). CONCLUSION: Patients with class III obesity had severe limb symptoms, typical of CVI, but approximately two thirds of the limbs had no anatomic evidence of venous disease. The association of increasing limb symptoms with increasing obesity suggested that the obesity itself contributes to the morbidity.     

Prophylaxis against venous thromboembolism in orthopedic surgery

Venous thromboembolism (VTE), which is manifested as deep vein thrombosis (DVT) and pulmonary embolism (PE), represents a significant cause of death, disability, and discomfort. They are frequent complications of various surgical procedures. The aging population and the survival of more severely injured patients may suggest an increasing risk of thromboembolism in the trauma patients. Expanded understanding of the population at risk challenges physicians to carefully examine risk factors for VTE to identify high-risk patients who can benefit from prophylaxis. An accurate knowledge of evidence-based risk factors is important in predicting and preventing postoperative DVT, and can be incorporated into a decision support system for appropriate thromboprophylaxis use. Standard use of DVT prophylaxis in a high-risk trauma population leads to a low incidence of DVT. The incidence of VTE is common in Asia. The evaluation includes laboratory tests, Doppler test and phlebography. Screening Doppler sonography should be performed for surveillance on all critically injured patients to identify DVT. D-Dimer is a useful marker to monitor prophylaxis in trauma surgery patients. The optimal time to start prophylaxis is between 2 hours before and 10 hours after surgery, but the risk of PE continues for several weeks. Thromboprophylaxis includes graduated compression stockings and anticoagulants for prophylaxis. Anticoagulants include Warfarin, which belongs to Vitamin K antagonists, unfractionated heparin, low molecular weight heparins, factor Xa indirect inhibitor Fondaparinux, and the oral IIa inhibitor Melagatran and ximelagatran. Recombinant human soluble thrombomodulin is a new and highly effective antithrombotic agent. Prophylactic placement of vena caval filters in selected trauma patients may decrease the incidence of PE. The indications for prophylactic inferior vena cava filter insertion include prolonged immobilization with multiple injuries, closed head injury, pelvic fracture, spine fracture, multiple long bone fracture, and attending discretion. Multiple-trauma patients are at increased risk for DVT but are also at increased risk of bleeding, and the use of heparin may be contraindicated. Serial compression devices (SCDs) are an alternative for DVT prophylaxis. Compression devices provide adequate DVT prophylaxis with a low failure rate and no device-related complications. Immobilization is one of important reasons of VTE. The ambulant patient is far less Ukely to develop complications of inactivity, not only venous thrombosis, but also contractures, decubitus ulcers, or osteoporosis ( with its associated fatigue fractures), as well as bowel or bladder complications.     

Treatment of superficial and perforator venous incompetence without deep venous insufficiency: is routine perforator ligation necessary?

PURPOSE: We investigated whether routine ligation of incompetent perforator veins is necessary in treatment of symptomatic chronic venous insufficiency (CVI) due to combined superficial and perforator vein incompetence, without deep venous insufficiency. METHODS: This was a retrospective review of prospectively collected data. Twenty-four limbs with both superficial and perforator venous incompetence but no deep venous insufficiency were identified at venous duplex scanning. Air plethysmography (APG) was performed preoperatively, to obtain venous volume (VV), venous filling index (VFI), ejection fraction (EF), and residual volume fraction (RVF) of the affected limb. Saphenous vein stripping from the groin to knee and powered transilluminated phlebectomy for varicosity ablation were performed in all patients. Postoperatively, all patients underwent duplex scanning and APG to determine the status of the perforator veins and hemodynamic improvement from surgery. RESULTS: Average patient age was 55.8 years; 62% of patients were women. CVI was class 3 in 4 limbs, class 4 in 12 limbs, and class 5 and class 6 in 4 limbs each. Postoperative duplex scans demonstrated that 71% of previously incompetent perforator vessels were now competent or absent. Significant improvement in all APG values was documented after superficial surgery. VFI improved from 6.0 +/- 2.9 preoperatively to 2.2 +/- 1.3 after surgery (P <.001); EF improved from 56.3 +/- 18 to 62 +/- 21 (P =.02); and RVF improved from 40.1 +/- 19 to 28.3 +/- 18 (P =.009). Mean preoperative symptom score (5.3 +/- 1.9) was significantly improved at mean follow-up of 18.3 months (1.4 +/- 1.2; P <.001). CONCLUSION: Patients with superficial and perforator vein incompetence and a normal deep venous system experienced significant improvement in APG-measured hemodynamic parameters and clinical symptom score after superficial ablative surgery alone. This suggests that ligation of the perforator veins can be reserved for patients with persistent incompetent perforator vessels, with abnormal hemodynamic parameters or continued symptoms after superficial ablative surgery.     

Is portal venous outflow better than systemic venous outflow in small bowel transplantation? Experimental study in syngeneic rats

Background/Purpose

Blood drainage of the graft into the recipient portal vein reestablishes the physiological venous outflow after small bowel transplantation (SBT). However, although this approach is likely beneficial for the host, it may be technically more demanding making portocaval venous drainage the preferred arrangement during human SBT. The aim of this study was to examine in a syngeneic model of SBT the possible benefits of portoportal anastomosis (PPA) vs portocaval anastomosis (PCA) in terms of body and organ weights and bacterial translocation.

Methods

Syngeneic SBT was carried out in 25 Brown-Norway male rats weighing 249 ± 17.5 g using either PPA (n = 13) or PCA (n = 12). Half the animals in each group were killed, respectively, on postoperative day 2 or 7. Liver, spleen, and lungs were weighed and under sterile conditions the regional lymph nodes were excised. The nodes and venous samples from the cava and portal veins were cultured for aerobes and anaerobes. Bacterial components were detected in blood by polymerase chain reaction. The findings in both groups were compared by χ² or Mann-Whitney U tests.

Results

Mean postoperative body weight change was −3.6% ± 1.5% in PPA and −6.0% ± 1.2% in PCA animals (ns) on day 2 and −6.5% ± 2.6% and −8.0% ± 5.0% (ns) on day 7. Liver, spleen, and lung weights were not significantly different between both groups on either end point. Gram-negative enteric bacteria were found in 3 of 7 PCA animals and 2 of 6 PPA animals at day 2 (ns) and in 1 of 6 and 4 of 6 on day 7 (ns). Aerobic gram-positive bacteria were found in 1 of 7 and 1 of 6 (ns), 3 of 6 and 3 of 6 (ns), respectively, in the 4 groups. Most positive cultures corresponded to portal blood and lymph node samples. There were no anaerobic growths.

Conclusions

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No body or organ weight change suggesting significant functional advantages of one technical alternative over the other could be demonstrated.

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Bacterial translocation in the absence of rejection was frequent after SBT independently of the variety of venous outflow used. No difference in bacterial translocation between both anastomosis could be demonstrated.

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Orthotopic venous drainage did not seem to be advantageous in the present experimental setting.

     

Do multiple venous anastomoses reduce risk of thrombosis in free-flap transfer? Efficacy of dual anastomoses of separate venous systems

Whether or not multiple venous anastomoses reduce the risk of free-flap failure is a subject of controversy. We report here, for the first time, on the importance of selecting 2 separate venous systems of the flap for dual anastomoses. The efficacy of multiple anastomoses was verified through a retrospective review of 310 cases of the free radial forearm flap transfer. Dual anastomoses of separate venous systems (the superficial and the deep) showed a lower incidence of venous insufficiency than single anastomosis did (0.7% versus 7.5%; P < 0.05). On the other hand, dual anastomoses of a sole venous system showed no significant difference in the incidence of venous insufficiency compared with single anastomosis (11.5% versus 7.5%; P = 0.48). Our results suggest that dual venous anastomoses of separate venous systems is conducive to reduced risk of flap failure and affords protection against venous catastrophe through a self-compensating mechanism that obviates thrombosis of either anastomosis.     

Central venous cannulation - always with ultrasound support?

Central Venous Cannulation - Always with Ultrasound Support?.Ultrasound guided puncture (UGP) improves success and complication rates of central venous cannulation. By some authors UGP with imaging devices are strongly recommended for all cannulations of subclavian or internal jugular veins. In order to review the current literature a computer based abstract search in Medline was performed for the period from January 1972 to May 2000 limited by the key words "catheterization, central venous catheter, internal jugular vein, subclavian vein, axillary vein, femoral vein, ultrasound, ultrasonography, Site-Rite und Smart Needle". UGP of the internal jugular vein was recommended in 29 prospective randomized studies, 21 prospective and three retrospective studies as well as in several clinical reports. UGP of the subclavian vein was supported by only 4 studies, whereas two studies did not show any improvement of puncture results with UGP. Due to the visualisation of the vessel and the cannula imaging techniques represent the "gold standard". However, with conventional Doppler devices nearly the same success rates can be obtained. It does not seem to be justified to perform every central venous cannulation with Doppler or ultrasound support. Each anaesthetist and intensive care physician should be able to perform central venous cannulation without a Doppler or ultrasound device. However, in cases of abnormal anatomy UGP can be helpful to prevent complications. Especially children, patients with coagulation disorders and physicians with limited experience in central venous cannulation can benefit from UGP.     

Surgeons’ experience of venous risk with CPA surgery

Neurosurgical Review - The study aims to systematize neurosurgeons’ practical knowledge of venous sacrifice as applied to the posterior fossa region and to analyze the collected data to...     

Microvascular changes in chronic venous insufficiency—a review

Chronic venous insufficiency is the result of an impairment of the main venous conduits, causing microvascular changes. The driving force responsible for the alterations in the microcirculation is probably the intermittently raised pressure propagated from the deep system into the capillaries. The capillaries are dilated, elongated and tortuous and their endothelium is injured (irregular luminal surface, increased cytopempsis, dilated interendothelial spaces). Through the latter an increased extravasation can be observed, leading to an enlarged pericapillary space, oedema in the interstitial tissue and to the clinical finding of swelling. Haemoglobin from extravasated erythrocytes and erythrocyte fragments in the pericapillary space is degraded to haemosiderin which is responsible for hyperpigmentation. Microthrombosis in the capillaries causes microinfarction and micronecrosis. Skin areas with severe microangiopathy have reduced numbers of perfused nutritional capillaries and are characterized by a low transcutaneous (tc) po₂. The increased blood flow in the deeper skin layers does not contribute to nutrition of the superficial skin layers. The microvascular ischaemia is patchy and appears to be the main factor determining trophic changes and venous ulceration. The process of microinfarction and micronecrosis is followed by the formation of a granulation tissue, proliferation of capillaries and fibroblasts and finally wound healing by formation of scar tissue destroying the microlymphatic network. Clinically this process leads to lipodermatosclerosis, atrophy and in its most extreme form to ulceration where the compensating mechanisms are no longer able to repair the damage.