Per Ohlin

Venous function assessed during a 5 year period after acute ilio-femoral venous thrombosis treated with anticoagulation

To determine the chronological changes of venous physiology following major thromboses, 20 patients were repeatedly examined for over 5 years after an acute ilio-femoral thrombosis which was treated with conventional anticoagulation. Radionuclide angiography showed that 70% of the patients had obstructive lesions of the iliac vein with only minor changes occurring from 6 months to 5 years. In spite of this, the plethysmographic maximum venous outflow increased from 31 to 45 ml/min/100 ml (P less than 0.001). The foot volumetric reflux did not change with time and about half of the patients had abnormal values. Venous reflux assessed by the refill time of foot vein pressure, deteriorated with time (P less than 0.05), and at 5 years all but one patient had a refill time less than 20 s. The muscle pump function, examined by foot volumetry, was abnormally low in about half of the patients throughout the study. The ambulatory foot vein pressure was constantly pathological (greater than 60 mmHg) in half of the patients and only two of 18 patients had normal values (less than 45 mmHg) at 5 years. Five patients with thromboses involving only the proximal veins had better physiological results than 15 patients with thromboses that extended to the peripheral veins. Three patients who developed venous claudication had iliac vein obstruction and an impaired venous outflow and three patients who developed venous ulcers had venous reflux and severe venous hypertension. Although venous outflow continuously improves following ilio-femoral thromboses, valvular competence and muscle pump function are constantly pathological, creating severe venous hypertension with a risk of post-thrombotic sequelae.

Thrombectomy with temporary arteriovenous fistula: The treatment of choice in acute iliofemoral venous thrombosis

The treatment of choice in acute iliofemoral venous thrombosis is still controversial. This prospective randomized study compares the results of conventional anticoagulation of 32 patients with the results obtained in 31 patients undergoing acute thrombectomy combined with a temporary arteriovenous fistula and anticoagulation. Early complications were few in both treatment groups, and significant pulmonary embolism developed in only one conservatively treated patient. At 6-month follow-up in all surviving patients, leg swelling, varicose veins, and venous claudication were more frequent after conservative treatment. Only 7% (2 of 27) of these patients were completely free from postthrombotic symptoms compared with 42% (10 of 24) of the operated patients (p less than 0.005). Contrast phlebography demonstrated an excellent venous outflow through the iliofemoral segment in 35% (9 of 26) of the conservatively treated and in 76% (16 of 21) of the operated patients (p less than 0.025). Open femoropopliteal veins with competent valves were recorded in 26% (7 of 27) in the conservative group and in 52% (12 of 23) in the thrombectomy group (p less than 0.05). Thus thrombectomy combined with arteriovenous fistula decreases early symptoms and preserves venous outflow and valvular function better than conservative treatment. This procedure is therefore recommended for young patients with acute iliofemoral thrombosis to avoid development of incapacitating postthrombotic sequelae.

Long-term results of venous thrombectomy combined with a temporary arterio-venous fistula*

Forty-one patients with acute iliofemoral venous thrombosis were randomised to conventional anticoagulation or acute thrombectomy combined with a temporary arterio-venous fistula (AVF) and anti-coagulation. Follow-up after 5 years in 22 medical and 19 surgical patients revealed slightly more asymptomatic patients (37 vs. 18%) and less frequent severe post-thrombotic sequelae (16 vs. 27%) in the surgical group (N.S.). The iliac vein was more frequently (P less than 0.05) normal following thrombectomy (71 vs. 30%) as demonstrated by radionuclide angiography, but occlusion plethysmography showed an outflow capacity (61 vs. 45 ml/min/100 ml) that was not significantly better. There was no obvious difference in muscle pump function (EVrel) and reflux (Q/EVrel) assessed by foot volumetry. Still, the ambulatory venous pressure was significantly (P less than 0.05) lower in the surgical group. There was a tendency towards better results following thrombectomy in patients with fresh thrombosis and a successful initial procedure. Although the numbers of observations in many cases were too small to provide statistical evidence of benefit with venous thrombectomy + AVF, this procedure seems to improve the long-term outcome following acute iliofemoral venous thrombosis. Since the difference in outcome is not very striking, anticoagulation treatment is still an acceptable alternative.

Intramuscular pressure, muscle blood flow, and skeletal muscle metabolism in chronic anterior tibial compartment syndrome.

One hundred eight patients with lower leg pain of unknown cause underwent intramuscular pressure measurements by the wick technique. Fifteen patients (14%) were found to have a chronic anterior tibial compartment syndrome. In these patients the intramuscular pressure was significantly increased at rest and during and after exercise as compared with normal subjects. The pressure increase after exercise was long-lasting (40 minutes). Biopsies of the anterior tibial muscles showed increased water content, which may explain the elevated pressures. Muscle blood flow during exercise as measured by the xenon-133 clearance technique was decreased, and muscle lactate concentration was increased in the anterior tibial muscles. Fasciotomy relieved pain and normalized intramuscular pressure, muscle blood flow, and skeletal muscle metabolism.

Pressures recorded in ulnar neuropathy

The pressure between the ulnar nerve and the arcade bridging the two heads of the flexor carpi ulnaris muscle was recorded peroperatively in ten patients with electrophysiologically confirmed ulnar neuropathy at the elbow. At rest, with the elbow extended, pressures ranged from 0 to 19 mm Hg but increased in flexion and during isometric contraction of the flexor carpi ulnaris muscle to maximal values above 200 mm Hg.

Does the Correction of Insufficient Superficial and Perforating Veins Improve Venous Function in Patients with Deep Venous Insufficiency

Thirty limbs in 25 patients with chronic deep venous insufficiency and recurrent ulceration were examined by ascending and descending contrast phlebography, occlusion plethysmography, foot volumetry and ambulatory venous pressure. Superficial venous insufficiency was surgically corrected by stripping of the saphenous vein and local excision of the varicosities (op1) in 12 limbs. Perforating venous insufficiency was then corrected by extensive subfascial ligation of perforating veins (op2) in all limbs. Venous outflow capacity, measured by occlusion plethysmography, and muscle pump function, measured by foot volumetry, were not affected by either procedure. Venous reflux, measured by foot volumetry, (Q/EVrel) and by venous pressure return time (RT90) improved significantly with op1 but no change was seen after op2. Venous hypertension decreased significantly with op1 but did not change after op2, and 59% of the limbs still had severe venous hypertension (> 60 mmHg) after both procedures. Initial clinical results were good, ulcers persisting in only three limbs, but recurrences occurred in an additional six limbs within 27 months. The limbs with persistent or recurrent ulcers had severe phlebographic reflux and severe venous hypertension. These results demonstrate that improvement in venous reflux and hypertension may be achieved by correction of superficial venous insufficiency, but the addition of ligation of perforating veins seems to be of less benefit to the venous circulation.

Intramuscular pressure in the lower leg in deep vein thrombosis and phlegmasia cerulae dolens.

The influence of deep vein thrombosis on intramuscular pressure was evaluated in 22 patients by means of the wick technique. Intramuscular pressure was measured in the anterior tibial and the deep posterior compartments in both legs before and during treatment. The intramuscular pressure was significantly (p less than 0.001) higher in the thrombosed leg than in the contralateral leg (0-16 mmHg). The increase in intramuscular pressure was related to the extension of the thrombus. Iliofemoral thrombosis caused a significantly (p less than 0.001) higher pressure (17-28 mmHg) than calf thrombosis (16-23 mmHg). A compartment syndrome was found to be a part of the entity phlegmasia cerulea dolens (rest pressure 47-56 mmHg). In the treatment of phlegmasia cerulea dolens, fasciotomy is suggested additional to other therapeutic procedures.

Intracompartmental forearm pressure during rest and exercise.

To investigate whether effort-related dorsal forearm pain could be due to an increase of the intracompartmental pressure (ICP) in the dorsal forearm compartment, the normal range of the ICP at rest and during exercise was first determined in 11 volunteers using a wick catheter. The ICP at rest was 6 mm Hg (range, 2-11 mm Hg), and during exercise the pressure rose to about six times the resting level. Fourteen patients with pain in the dorsal forearm during exercise were similarly examined. In six patients the pressure at rest and/or during exercise was more than twice that of the normal persons or that of the healthy forearm. After fasciotomy four of these six patients were relieved of pain within three weeks, which might suggest a relation between ICP and pain.

Physiologic and therapeutic aspects in congenital vein valve aplasia of the lower limb.

Ten patients with congenital vein valve aplasia verified at contrast phlebography were evaluated clinically and by physiologic examinations. All had orthostatic edema and varicose veins, but leg ulcers and other “postphlebitic” sequelae were infrequent. Foot volumetry and measurement of ambulatory foot vein pressures revealed a severe deep venous incompetence with a defective muscle pump function and considerable reflux. Eight limbs were operated on with conventional varicose vein surgery and physiologically re-examined six to 26 weeks after the operation. All had an improved ambulatory pressure reduction (p > 0.001). Foot volumetry revealed better muscle pump function (p > 0.01), while the reflux flow was unchanged. Surgery of the incompetent superficial venous system is therefore recommended in cases with deep venous insufficiency due to congenital vein valve aplasia.

Pysiological Evaluation of Venous Obstruction in the Post-Thrombotic Leg

The accuracy and value of occlusion plethysmography (OP) in assessing post-thrombotic iliac and femoral vein obstruction was determined in 45 patients (85 legs) six months after an acute iliofemoral venous thromboses using contrast phlebography (CP) as reference method. The additional value of femoral venous pressure (FVP) measurements in assessing the physiological importance of iliac vein obstructions was determined in 34 of these patients (60 legs). The sensitivity and specificity of OP in detecting femoral and iliac vein obstructions was 79% and 84% respectively. OP was unable to distinguish femoral from iliac lesions and stenosis from obstructions. A maximum venous outflow (MVO) <30 ml·100 ml−1 ·min−1 was greatly associated with venous obstruction which was very uncommon if the MVO >50 ml·100 ml−1 ·min−1. Resting FVPs were of little value in assessing iliac venous outflow. Exercise pressures and comparison with normal contralateral veins improved the association with anatomical obstruction. A difference in FVP change with exercise exceeding l mmHg as compared to the contralateral leg was most predictive of an iliac vein obstruction. Patients with obvious clinical symptoms of venous outflow obstruction (venous claudication) all had iliac vein obstruction, abnormal OP and an FVP change with exercise exceeding 5 mmHg. This demonstrates the ability of OP and FVP to reflect physiological rather than morphological post-thrombotic venous obstruction.