Complete Venous Occlusion Research Articles

First Aid for Failing Flaps

Wound coverage with pedicled (local, regional, or distant) or free flaps is commonplace throughout plastic surgery. However, irrespective of the method of tissue transfer or type of tissue being transferred, inflow and outflow remain key parameters for success. Much has been written detailing complex tissue transfers and delineating arterial and venous anatomy. Despite this, simple venous insufficiency causing venous congestion is common. In experimental models, when arterial inflow is impaired, even mild venous inadequacy affects flap survival. Furthermore, studies have shown that venous congestion is more detrimental to the rate and percentage of flap area surviving than arterial ischemia. Obviously, complete venous occlusion typically requires operative exploration and correction, but many instances occur when venous congestion occurs for reasons other than complete venous thrombosis. Here we detail the basic postoperative "first aid" techniques available to optimize venous drainage. Although these techniques are not a substitute for sound anatomic flap selection, good surgical technique, or re-operation when a significant underlying problem exists, they do offer additional options to improve flap outcomes.

VIDEO MICROSCOPE RECORDING OF THE DYNAMIC COURSE OF THROMBOSIS AND THROMBOLYSIS OF THE RETINAL VEIN IN RABBITS

The purpose of this study was to investigate the dynamic course of experimental thrombosis and thrombolysis of the retinal veins. Dynamic changes in the blood flow in the retinal veins were documented on a digital recorder through a microscope-mounted video camera and were analyzed on a monitor by video playback. Photochemical thrombus formation was induced by intravenous injection of 30% Rose Bengal followed by endoillumination of individual branch retinal veins of the eyes of 20 anesthetized pigmented rabbits. Subsequently, 10 rabbits were treated with an infusion in an ear vein of 3 mg/kg recombinant tissue plasminogen activator, whereas 10 control rabbits were administered with similar volumes of normal saline solution. Occlusion and recanalization were confirmed histologically and assessed by video microscopy. At the site exposed to light, photochemical injury resulted in the formation of a white thrombus, stagnation of blood flow, and subsequent complete venous occlusion in 20 rabbits. In this study, of the 10 animals in the recombinant tissue plasminogen activator treatment group, 9 (90%) showed evident thrombolysis, whereas none of the control group animals showed evident thrombolysis. The video showed that the massive thrombus disrupted into nonuniform fragments, which were quickly washed away by the blood flow, and the circulation was reestablished with no recurrence of secondary obstruction. In vivo data suggest that video microscopy may provide a visual approach for observing the dynamic changes occurring during experimental thrombus formation and lysis by the early administration of recombinant tissue plasminogen activator; this approach may assist in future investigation of thrombus research of ocular fundus.

Early detection of complete venous occlusion in a rodent and swine pedicle flap model using modulated imaging, a new novel multispectral imaging technique

Author(s): Pharaon, Michael R; Scholz, Thomas; Bogdanoff, Scott; Cuccia, David; Durkin, Anthony J; Hoyt, David B; Evans, Gregory RD

Successful Treatment of Phlegmasia Cerulea Dolens with Combination Surgical and Catheter-Assisted Thrombectomy

Phlegmasia cerulea dolens is a rare condition caused by complete venous occlusion that leads to impaired arterial flow. Prompt diagnosis and treatment initiation are paramount in preventing progression to gangrene, the need for amputation, and possibly the death of the patient. Thrombolysis or surgical thrombectomy, for advanced disease and cases in which anticoagulation is contraindicated, represent the current standard treatment. Here we report the case of a 47-year-old male who sustained severe trauma during a car accident. After having a prophylactic retrievable inferior vena cava filter placed, he developed caval thrombosis with progression to phlegmasia cerulea dolens. He was successfully treated with a combination of surgical thrombectomy of the lower extremity veins and catheter-assisted thrombectomy of the iliac veins and inferior vena cava, in the setting in which an initial attempt at balloon thrombectomy of the iliac veins and inferior vena cava failed. He was discharged from the hospital in stable condition and on follow-up visits had full resolution of symptoms. Ultrasound evaluation showed no residual venous clot. The presented case illustrates how the use of catheter-assisted thrombectomy alleviated the need for a laparotomy and direct caval evacuation of the thrombus and provided a timely and effective treatment of phlegmasia cerulea dolens with impending gangrene.

Endovenous Microwave Ablation of Varicose Veins

This study aims to investigate the application of the microwave generator to treat the patients with varicose veins. Phase 1: Explanted saphenous veins in subcutaneous layer of the pork meat were ablated at 0, 40, 50, 60, and 70 W. Phase 2: The forelimb veins and the hindlimb arteries of a 40-kg swine were ablated at 50 and 60 W. Phase 3: The patients were treated with endovenous microwave ablation at 50 W. Phase 1: Perivenous tissue injury was found in groups 50, 60, and 70 W. Phase 2: Less perivenous tissue injury was found in group 50 W. Phase 3: Complete venous occlusion rate was 65% and venous reflux-free was 85% in 1 year. No severe complication was found. The microwave generator with 50-W power setting could be used to ablate the varicose veins safely.

Complete Pulmonary Venous Occlusion After Radiofrequency Ablation for Atrial Fibrillation

Pulmonary vein stenosis is a known, yet under-recognized complication of radiofrequency ablation for atrial fibrillation. We present the case of a patient developing complete left-sided pulmonary venous occlusion following radiofrequency ablation. Recommendations are made to allow earlier diagnosis of this complication.

Local Cooling Provides Muscle Flaps Protection from Ischemia-Reperfusion Injury in the Event of Venous Occlusion during the Early Reperfusion Period

Clinicians often place patients in heated rooms following muscle flap transfers. We hypothesize that exposure of flaps to heated room temperatures could result in an unnecessary hyperthermic ischemic insult if the flaps were to be compromised by venous outflow obstruction, while exposure of elective flaps to local cooling during early perfusion may provide protection in the event of venous occlusion. The rat rectus femoris muscle flap was elevated and clamped for 1 h. The muscle was then exposed to various temperatures for 1 h of perfusion followed by complete venous occlusion for 3 h. Occlusion clamps were removed and flaps were allowed to reperfuse for 24 h. Flaps were assessed for muscle necrosis and edema. Venous occluded muscles demonstrated decreased muscle necrosis and edema in the locally cooled group (8.5 +/- 6.7%, 3.06 +/- 0.14; P < 0.001) compared to the room temperature group (76.2 +/- 23.0%, 3.73 +/- 0.13), and the local warming group (97.3 +/- 1.4%, 3.84 +/- 0.29) respectively. No difference was noted in muscle necrosis nor edema amongst non-ischemic muscles irrespective of temperature exposure. These results suggest a beneficial role for exposure of elective flaps to local cooling during the early perfusion period in order to provide protection from ischemia reperfusion injury in the event of a venous occlusion insult. The prophylactic exposure of flaps to local cooling is further supported by the lack of a harmful effect when flaps were not compromised by venous occlusion.

A Case of Phlegmasia Cerulea Dolens as a Complication Caused by Placement of Inferior Vena Cava Filter

Inferior vena cava filters are increasingly being used as an alternative to anticoagulation therapy for the prevention of pulmonary embolism. However, using an Inferior vena cava filter may result in clinically significant complications. Phlegmasia cerulea dolens is a rare disease that presents with acute complete venous occlusion due to extensive thrombosis in the lower extremity. It is characterized by intense pain, edema, decreased pulses and a cyanotic extremity. We report here on a case of phlegmasia cerulea dolens that was accompanied with disseminated intravascular coagulation (DIC) as a complication of the placement of an inferior vena cava filter in a patient who had been previously diagnosed with pulmonary embolism, and the patient had recently developed a cerebral hemorrhage due to a traffic accident. (Tuberc Respir Dis 2008;65:225-229)

Successful catheter-directed venous thrombolysis in phlegmasia cerulea dolens

Background Phlegmasia cerulea dolens is an extremely rare condition caused by complete venous occlusion and often results in tissue necrosis, limb amputation, or death. Treatment options include systemic anticoagulation, systemic thrombolytic therapy, fasciotomy, or surgical thrombectomy. Rare case reports have described the use of catheter-directed thrombolysis in the treatment of this condition. Prompt diagnosis and treatment initiation are important to prevent gangrene, amputation, and ultimately death. Case We report two unusual cases of phlegmasia cerulea dolens that presented in patients with aggressive gynecologic malignancies and who were successfully treated with catheter-directed thrombolytic therapy. Conclusion To maximize the opportunity for limb salvage, catheter-directed venous thrombolytic therapy should be considered in the treatment of phlegmasia cerulea dolens that presents in the gynecologic oncology patient.

Venous Obstruction After Pacemaker Implantation

Central vein leads are known to predispose to venous obstruction. Although usually asymptomatic, obstruction may render electrode removal difficult. This study aimed at quantifying changes in venous calibers in a prospective fashion by intravenous contrast venography (ICV) before and after pacemaker (PM) or cardioverter-defibrillator implantation. One hundred and fifty (mean age 67; 61% male) consecutive patients were enrolled, and followed for 6 months. A successful ICV was done at baseline prior to implantation and at 6-month follow-up in 136 (91%) patients. Minimum (D(min)) and maximum (D(max)) vessel diameters were obtained from both ICVs. A new stenosis was defined as a 50% diameter reduction in a venous segment when compared to baseline. We implanted a total of 230 electrodes: 47 (34.6%) single lead, 84 (61.8%) 2-lead, and 5 (3.7%) 3-lead systems. At baseline ICV, 10 patients (7%) were found to have venous anomalies, including 8 patients with obstructive lesions, 1 patient with a persistent left superior vena cava, and 1 patient with double axillary vein. At 6 months, a new obstructive venous lesion had developed in a total of 19 (14%) patients, none of whom exhibited any local symptoms. Of these patients 14 (10%) had a stenosis (mean D(min) 4.6 mm and diameter 38% of baseline), and 5 (3.6%) had a complete venous occlusion. In most cases the new stenosis developed in a location where the vessel was narrowest at baseline. Clinical predictors for the development of stenosis were atrial fibrillation at baseline and biventricular PM implantation. This is the first systematic study to quantify venous changes after PM or ICD implantation. Our study shows that venous anomalies rendering PM implantation difficult are not infrequent. The incidence of new venous obstruction was 14%. Atrial fibrillation and biventricular PM implantation were independent predictors of venous obstruction.

Cutaneous Tissue Flap Viability following Partial Venous Obstruction

Venous outflow obstruction is the most common cause of tissue failure after microvascular reconstructive surgery. If it is not recognized early, there is an increased risk of tissue damage and loss. Currently, however, there are no adequate models for the study of this clinical problem. The purpose of this study was to develop a partial congestion model for the study of skin flap physiology in response to varying levels of occluded venous outflow. Nine mixed-breed pigs were equally divided into three experimental groups (0 percent, 20 percent, and 50 percent venous outflow) to determine the effects of varying venous outflow on cutaneous flap color, oxygen tension, and edema. A cutaneous pedicle flap model and a partial congestion system were used to observe changes in variable venous obstruction. Only 0 percent venous outflow resulted in progressive color change across time. In addition, 0 percent venous outflow demonstrated significantly different oxygen tension levels relative to the other groups. Twenty percent venous outflow resulted in significant edema formation relative to the other groups. The 50 percent group showed an increase in oxygen tension from the second hour of venous obstruction to the end of the experiment. Tissue flap color is the clinical standard on which flap health is measured. After 8 hours, only complete venous occlusion resulted in significant color change. However, physiological changes that could affect tissue flap health were noted with only partial venous occlusion, including the development of edema formation. Accordingly, subtle color change could indicate partial venous congestion and may warrant intervention by the surgeon.

Prevalence of Venous Anatomic Variants and Occlusion Among Patients Undergoing Implantation of Transvenous Leads

The implantation of transvenous leads may be prohibited by venous occlusion or anatomical variants. The prevalence of these conditions among patients undergoing transvenous pacing or implantable cardioverter defibrillator (ICD) leads implantation has not been systematically studied. This study examined the prevalence of venous anatomic variants and/or venous occlusion, and related risk factors, prior to lead implantation. The study included 273 consecutive patients scheduled for implantation of transvenous pacing or ICD leads. Before the procedure, the venous network of arms, neck, and thorax was evaluated by bilateral intravenous digital subtraction angiography (DSA). Complete venous occlusion associated with developed collateral circulation was observed in 12 patients (4.4%); at the site of the left innominate vein in 9, left subclavian vein in 2, and right subclavian vein in 1 patient. Of 12 patients with venous occlusion, 7 patients had a history of prior surgical procedure. A persistent left superior vena cava was observed in 1 patient (0.4%). The presence of abnormal findings on DSA was significantly higher on the left than the right side (P < 0.001). The cardio-thoracic ratio (CTR) was significantly greater in patients with venous occlusions than patients with normal circulation (P = 0.012). Asymptomatic venous abnormalities are not rare among patients requiring transvenous pacing lead implantation. Careful attention should be paid when implanting pacing or ICD leads from the left side, especially in patients with an increased CTR or history of prior insertion for central venous catheter.

Percutaneous treatment of symptomatic central venous stenosis angioplasty

Objectives The increased use of central venous access primarily for hemodialysis has led to a significant increase in clinically relevant central venous occlusive disease (CVOD). The magnitude of and the optimal therapy for CVOD are not clearly established. The purpose of this study is to define the problem of CVOD and determine the success of percutaneous therapy for relieving symptoms and maintaining central venous patency. Methods Patients presenting with disabling upper-extremity edema suggestive of central venous stenosis or occlusion during a 3-year period were evaluated by venography of the upper extremity and central veins. Percutaneous venous angioplasty (PTA) and/or stent placement was performed as clinically indicated. The success of therapy was assessed, and the patients were observed to determine the incidence of recurrence and additional procedures. Recurrent lesions underwent similar evaluation and treatment. Results A total of 32 sides were treated in 29 patients with a mean of 1.9 interventions per side treated. Hemodialysis-related lesions were the underlying cause in 87% with the remaining 13% related to previous central venous catheterization. The lesions involved the axillary, subclavian, and innominate veins with complete venous occlusion in six (19%) cases. Percutaneous angioplasty was followed by stent placement in six (19%) cases. The procedure was a technical success and was performed without complications in all cases (100%). Mean follow-up was 16.5 months (range, 4-36 months). On average, patient symptoms were controlled for 6.5 months after the initial intervention. Recurrent edema led to additional PTA in 20 (63%) cases. Fifty percent (n = 14) of patients with an arteriovenous fistula (AVF) experienced recurrent symptoms after initial and/or repeat PTA and required AVF ligation. Complete resolution after the initial PTA was predictive of long-term success. Conclusions Central venous occlusive disease has emerged as a significant clinical problem. Percutaneous venous angioplasty can provide temporary symptomatic relief; however, multiple procedures are often required and long-term relief is rarely achieved.

Tissue Carbon Dioxide Tension:

Free flap surgical procedures are technically challenging, and anastomosis failure may lead to arterial or venous occlusion and flap necrosis. To improve myocutaneous flap survival rates, more reliable methods to detect ischemia are needed. On the basis of theoretical considerations, carbon dioxide tension, reflecting intracellular acidosis, may be suitable indicators of early ischemia. It was hypothesized that tissue carbon dioxide tension increased rapidly when metabolism became anaerobic and would be correlated with acute venoarterial differences in lactate levels, potassium levels, and acid-base parameters. Because metabolic disturbances have been observed to be less pronounced in flaps with venous occlusion, it was hypothesized that tissue carbon dioxide tension and venoarterial differences in lactate and potassium levels and acid-base parameters would increase less during venous occlusion than during arterial occlusion. In 14 pigs, latissimus dorsi myocutaneous flaps were surgically isolated, exposed to acute ischemia for 150 minutes with complete arterial occlusion (seven subjects) or venous occlusion (seven subjects), and reperfused for 30 minutes. After arterial occlusion, pedicle blood flow decreased immediately to less than 10 percent of baseline flow. Blood flow decreased more slowly after venous occlusion but within 3 minutes reached almost the same low levels as observed during arterial occlusion. Venous oxygen saturation decreased from approximately 70 percent to approximately 20 percent, whereas oxygen uptake was almost arrested. Tissue carbon dioxide tension increased to two times baseline values in both groups (p < 0.01). The venoarterial differences in carbon dioxide tension, pH, base excess, glucose levels, lactate levels, and potassium levels increased significantly (p < 0.01). Tissue carbon dioxide tension measured during the occlusion period were closely correlated with venoarterial differences in pH, base excess, glucose levels, lactate levels, and potassium levels (median r2, 0.67 to 0.92). After termination of arterial or venous occlusion, more pronounced hyperemia was observed in the arterial occlusion group than in the venous occlusion group (p < 0.05). Oxygen uptake (p < 0.05) and venoarterial differences in lactate and potassium levels (p < 0.05) were significantly more pronounced in the arterial occlusion group. In the venous occlusion group, with less pronounced hyperemia, venoarterial differences in acid-base parameters remained significantly different from baseline values before occlusion (p < 0.01). The data indicate that tissue carbon dioxide tension can be used to detect anaerobic metabolism, caused by arterial or venous occlusion, in myocutaneous flaps. The correlations between carbon dioxide tension and venoarterial differences in acid-base parameters were excellent. Because carbon dioxide tension can be measured continuously in real time, such measurements are more likely to represent a clinically useful parameter than are venoarterial differences.

Retropharyngeal rhabdomyosarcoma mimicking pseudotumor cerebri

A 6-year-old male presented with headache, vomiting, visual obscuration, and papilledema. Clinical presentation, initial laboratory data, and radiologic evaluation suggested a diagnosis of pseudotumor cerebri. The development of lower cranial nerve palsies after transient resolution of symptoms prompted reassessment of the diagnosis, which revealed retropharyngeal rhabdomyosarcoma involving the right jugular vein. Cerebral angiography demonstrated the complete venous occlusion at the jugular foramen. Careful neurologic follow-up is essential in a patient with pseudotumor cerebri or idiopathic intracranial hypertension.

Vena cava occlusion with balloon to control blood pressure during deployment of transluminally placed endovascular graft

Transluminally placed endovascular graft (TPEG) replacement has been applied to treat various aortic diseases. At the moment of deployment, TPEG receives a pressure pulse force to shove it distally, which possibly results in misplacement. Moreover, deploying the TPEG in the aorta increases cardiac afterload, which may damage myocardial function. To avoid these risks, we developed a new technique to control blood pressure by almost complete venous return occlusion. Two occlusion balloon catheters are inserted into the superior and inferior vena cava via the femoral vein. TPEG is deployed at the proper position during inflation of the vena cava balloon to maintain a blood pressure as low as 60 mm Hg by cardiac preload blockage. We, thus far, have not experienced even a trivial sequela with this technique.

Renal transplant vein stenosis: Demonstration and percutaneous venoplasty of a new vascular complication in the transplant kidney

Stenosis of the renal transplant vein has been demonstrated in eight patients undergoing investigation for renal dysfunction arising 3 weeks to 3 years after transplantation. The stenoses were diagnosed by duplex Doppler ultrasound in three cases and by angiography in the presence of arterio-venous fistula in five cases. In four patients percutaneous venous dilatation was performed with technical success in three. In two patients this was repeated for recurrent stenosis but sustained improvement in renal function was not observed. Progression of the venous stenoses was documented with one patient suffering graft loss due to complete venous occlusion.

Evaluation of the Microcirculation in a Sheep Island Pedicle Flap with Laser Doppler Flowmeter And99m-Tc-Labelled Red Blood Cells

The aim of the study was experimentally to evaluate the capability and reliability of laser Doppler flowmetry (LDF) in conditions of circulatory deficiency, by correlating it to flow-related parameters measured by a radionuclide-imaging technique and using 99m-Tc red blood cells (RBCs). For this purpose, a pedicle island flap in the sheep was used, with well-perfused proximal parts and with evident stasis in the distal third of the flap. No correlation was found between results obtained with the two techniques. In regions with evident stasis, falsely high LDF readings were recorded. This may be due to a back-and-forth motion of the RBCs under the probe, rather than to true flow. It was concluded that, while LDF seems reliable in detecting complete arterial occlusion, it is unreliable in predicting either complete venous occlusion or partial obstruction of the flow to and from the flap. Clinical use for this purpose cannot be recommended.

Transanal and intraperitoneal prolapse in intussusception

An infant with intussusception who developed an unusual complication of transanal and intraperitoneal prolapse is reported. Complete venous occlusion of the intussusceptum for a prolonged period in a patient with congenital anomalous vascular supply of the colon is suggested as a mechanism responsible for rupture of the intussuscepiens.

Automated venous occlusion plethysmograph.

A self-contained automated system for venous occlusion plethysmography is described. The system is microprocessor controlled and performs the complete venous occlusion plethysmographic process of measurement, analysis and printout of results at the command of two keypresses on a keypad. Limb circulation is modelled by a linear model. Limb volume change is measured by electrical impedance plethysmography. The system is convenient to use clinically, either for the measurement of blood flow in the legs or for the diagnosis of venous thromboembolic disease. The hardware and data processing software of the system are described and examples from clinical use of the system are presented.