Venous valve station changes in "primary" and postthrombotic reflux: an analysis of 149 cases

The purpose of this study was to analyze valve station changes noted during venous valve reconstruction and the associated outcome. One hundred and forty-nine valve reconstructions were available for analysis at the time of surgical exploration; the venous valve was graded according to valve station changes (VS grades) from zero through six. Ascending venography was analyzed by a similar grading system and the two methods were compared. The results of this analysis showed that valve station wall changes are frequently present in patients with deep venous reflux and pose technical challenges during valve reconstruction; the outcome, however, appears unaffected. Grade 0 to 1 valve station changes are predominantly due to "primary" reflux, with an occasional instance of postthrombotic etiology. Grade 2 or 3 valve station changes are roughly evenly divided between phlebosclerosis of primary reflux and postthrombotic etiologies. The mechanism of onset of reflux with preservation of valve cusps in the latter group of postthrombotic cases is probably different from currently accepted theories of evolution of postthrombotic changes. Postthrombotic valve damage is variable, and the valve station anatomy may be sufficiently preserved in some patients to allow direct valve repair.

Popliteal vein entrapment: a benign venographic feature or a pathologic entity?

PURPOSE

Asymptomatic morphologic popliteal vein entrapment is frequently found in the healthy population (27%). In our institution, popliteal vein compression on plantar flexion was observed in 42% of all ascending venograms. Some authorities consider the lesion benign, without pathologic significance. This study examines the pathophysiologic importance in select patients, describes treatment with surgery, and suggests a diagnostic tool.

METHOD

Thirty severely symptomatic patients with venographic evidence of popliteal entrapment were selected to have popliteal vein release after a process of elimination (ie, other causes of chronic venous insufficiency [CVI] were ruled out by means of comprehensive hemodynamic and morphologic studies). In the last nine limbs, popliteal vein pressure was also measured by means of the introduction of a 2F transducer tip catheter. Patients were clinically and hemodynamically assessed before and after surgery, and anatomical anomalies encountered during surgery were recorded.

RESULTS

Popliteal vein release was performed without mortality or serious morbidity. Anomalies of the medial head of the gastrocnemius muscle caused entrapment in 60% of the patients; anatomic course venous anomalies were infrequent (7% of the patients). Significant relief of pain and swelling occurred in the patients who had surgery. Stasis ulceration/dermatitis resolved in 82% of patients. Popliteal venous pressures had normalized in the six patients who were studied postoperatively.

CONCLUSION

Popliteal vein entrapment should be included in the differential diagnosis of CVI in patients in whom other, more common etiologies have been excluded on the basis of comprehensive investigations. Popliteal vein compression can be demonstrated venographically in a large proportion of patients with CVI, but the lesion is likely pathological only in a small fraction of these patients. A technique for popliteal venous pressure measurement is described; it shows promise as a test for functional assessment of entrapment. Immediate results of popliteal vein release surgery are encouraging; long-term follow-up is necessary to judge the efficacy of surgical lysis of entrapment in symptomatic patients who fail to improve with conservative treatment measures.

Balloon dilation and stenting of chronic iliac vein obstruction: technical aspects and early clinical outcome

PURPOSE

To describe the technical aspects of percutaneous balloon dilation and stenting for the treatment of venous outflow obstruction in chronic venous insufficiency.

METHODS

Between March 1997 and December 1998, 94 consecutive patients (median age 48 years, range 14 to 80) with suspected iliac vein obstruction in 102 limbs were studied prospectively with the intent to treat any venous occlusion or stenosis verified during femoral vein cannulation. Data from the history, clinical examination, procedure, and follow-up were recorded. Preoperative indicators of obstruction were venographic evidence of occlusion, stenosis, or pelvic collateral vessels; increased arm-foot venous pressure differential; and abnormal hyperemia-induced venous pressure elevation.

RESULTS

Cannulation and technical success rates were 98% and 97%, respectively, with 118 Wallstents deployed in 77 veins. Primary, assisted primary, and secondary patency rates at 1 year were 82%, 91%, and 92%, respectively. Clinical improvement in pain and swelling was significant.

CONCLUSIONS

Stenting of benign iliac vein obstruction is a safe method with good short-term results. Venous lesions should always be stented; when treating iliocaval junction lesions, stents should be inserted well into the inferior vena cava. Absence of collateral vessels does not exclude the existence of significant obstruction, and their presence may indicate an obstruction not visualized. No gold standard for accurate pre- or intraoperative patient selection is currently available.

A multicenter, phase I evaluation of cryopreserved venous valve allografts for the treatment of chronic deep venous insufficiency

PURPOSE

A phase I feasibility study was conducted to determine whether cryopreserved venous valved segments would remain patent/competent in a short-term period (6 months).

METHODS

The target group consisted of 10 patients (C(4-6), E, A(D), P(R)). The exclusion criteria included untreated superficial/perforator venous disease, significant venous or arterial obstruction, hypercoagulability or coagulopathy, and significant preexisting medical conditions. Required preoperative tests were venous duplex, ascending/descending venography, and a physiologic study (eg, APG, blood typing, an ankle/brachial index, and if post-thrombotic, a hypercoagulability work-up). A single-valve transplant was placed below all reflux, aided by anticoagulation with or without a distal arteriovenous fistula. Postoperative assessment included duplex scanning/clinical examination (at 1, 3, and 6 months), descending venogram (at 1 month), and physiologic study (at 1 and 6 months). The primary end point was valve patency/competence, with clinical outcome as a secondary end point. Adverse events were recorded.

RESULTS

After eliminating protocol violations, nine patients with superficial femoral (5) or popliteal (4) vein valve transplants were studied. Six-month actuarial results show a patency rate of 67% +/- 16% and 78% +/- 13%, respectively, a primary and secondary competency rate of 56% +/- 17% and 67% +/- 16%, respectively, and a 100% patient survival rate. Clinical outcome averaged 1.1, with healing and/or freedom from ulcer recurrence, in six of nine patients. A postoperative risk of seroma formation (3) and cellulitis (1) exists.

CONCLUSION

In patients with few remaining therapeutic options, one can achieve a 6-month assisted patency and competency rate of 78% and 67%, respectively, with an improved clinical outcome.

Axillary vein transfer in trabeculated postthrombotic veins

PURPOSE

This study assessed whether axillary vein transfer can be successfully performed in trabeculated veins and whether patients with this severe form of postthrombotic syndrome can be helped by an aggressive approach.

METHODS

A total of 102 axillary vein transfer procedures were carried out in 83 limbs with trabeculated veins. More than one venous segment was repaired in 38 limbs with a second axillary valve in 19, and a different technique was used in the remainder. The superficial and deep femoral veins were the most common target sites. "Bench repair" of leaky axillary valves was performed before the transfer in 32 cases. Venous stasis dermatitis or ulceration was present in 90% of the limbs. The operability rate and chance of successful valve reconstruction was high, even in the presence of severe venographic appearance.

RESULTS

The actuarial transplant patency rate was 83% at 10 years. The actuarial freedom from recurrent ulceration rate was more than 60% at 10 years, similar to the results obtained in a matched group of axillary vein transfers to nontrabeculated veins. Severe preoperative ambulatory venous hypertension (venous filling time [VFT] of less than 5 seconds), which was present in 67% of patients, did not adversely affect outcome, but short VFTs that persisted after surgery did. VFT and VFI90 (venous filling index, air plethysmography) improved after valve transfer. Swelling disappeared or was significantly reduced in 55% of patients (11 of 20 patients) who had moderate or severe preoperative swelling. In 82% of patients (31 of 37 patients) who had mild or no preoperative swelling, the swelling remained stable after surgery, and in 18% of patients (6 of 37 patients), it became worse. Pain was significantly diminished in 70% of patients; 23% of patients with severe pain had complete resolution.

CONCLUSION

Axillary vein transfer, in combination with other antirefluxive procedures when indicated, is safe, effective, and durable in patients with trabeculated veins and severe forms of postthrombotic syndrome. It may be considered as an option when conservative therapy or other types of surgery fail.

Studies in calf venous pump function utilizing a two-valve experimental model

OBJECTIVES

to explore the hydrodynamic mechanisms involved in the regulation of ambulatory venous pressure.

DESIGN

an experimental model of calf venous pump was constructed with collapsible tubes and valves.

MATERIAL

the model consisted of a conduit and a pump with an intervening competent valve. Another valve that could allow reflux into the pump was mounted above the pump.

METHODS

conduit pressure and recovery times were monitored under conditions of different degrees of ejection fraction and reflux into the pump. Model variables included using poorly compliant tubes for the pump, the conduit and for both the pump and conduit.

RESULTS

the latex tube exhibited a non-linear volume-pressure relationship and a bi-modal regimen of compliance. This bestowed pressure-buffering properties. Ambulatory venous hypertension resulted when reflux beyond buffering capacity occurred. Substituting less compliant PTFE for latex at the pump had a relatively minor effect on post-ejection pressure and recovery times. Using PTFE at the conduit had a profound but divergent effect on both of these parameters. Conduit capacitance reduction had a similar effect.

CONCLUSION

conduit elastance plays a significant role in the regulation of ambulatory venous pressure in this experimental model. The hydrodynamic principles illustrated by the model may enhance our understanding of the human calf venous pump.

Hemangioma of penis

Hemangioma of the shaft of the penis in a young man is presented for rarity of the growth and rarity of the site encountered in venereology practice.

Enterotoxigenicity of Klebsiella pneumoniae associated with childhood gastroenteritis in Madras, India

Klebsiella pneumoniae was isolated as the predominant growth from 12 of 100 children under 3 years of age suffering from acute diarrhea. Of the 12 isolates, SA1, SA2, SA4, SA5, SA6 produced a secretogenic response in the ligated rabbit ileal loop, and one isolate, SA3, induced a diarrheagenic response in suckling mice. Two isolates, SA7 and SA8, were diarrheagenic in both assays. Strains SA9, SA10, SA11, and SA12 were found to be non-enterotoxigenic. These isolates belonged to serotypes K6, 16, 25, 30, 39, 46, 49, 53, 66, and 81. All eight enterotoxigenic strains were resistant to ampicillin, streptomycin, ceftazidime, cefuroxime, and cotrimoxazole. Only quinolones such as ciprofloxacin and norfloxacin appear to be effective against enterotoxigenic K. pneumoniae.

Dapsone induced pulmonary eosinophilia without cutaneous allergic manifestations--an unusual encounter--a case report

Dapsone is a drug of choice in the treatment of leprosy. In addition it is very useful in the treatment of many other dermatological conditions. The "dapsone-induced hypersensitivity" is not unknown. However, to the best of our knowledge, pulmonary eosinophilia induced by dapsone without any cutaneous allergic manifestation has not been reported in leprosy patients. Pulmonary eosinophilia (Loeffler's syndrome) induced by dapsone without cutaneous manifestation has been reported in a non leprosy patient by Janier et al. We report a case of pulmonary eosinophilia associated with dapsone therapy in a patient with lepromatous leprosy without allergic cutaneous manifestations and our experience in the management of this patient.

Saphenectomy in the presence of chronic venous obstruction

BACKGROUND

The results of saphenectomy in patients with morphologic and functional obstruction were compared with those in patients without obstruction. Excision of secondary saphenous varices associated with deep venous obstruction has long been considered contraindicated for fear of compromising its collateral contribution. Recent advances in accurate functional assessment of venous obstruction make it possible to test this concept.

METHODS

Saphenectomy was carried out in 51 limbs without morphologic or functional obstruction and 64 limbs with varying grades of venous obstruction. Significant deep venous obstruction on ascending venography was present in the latter group. Functional assessment of obstruction was based on the arm/foot venous pressure differential technique, outflow fraction measurements, and outflow resistance calculations. Valve reconstruction was carried out in conjunction with saphenectomy in 81% of cases.

RESULTS

Saphenectomy was clinically well tolerated in both groups, and there was no difference in outcome as measured by objective tests for obstruction; improvement in reflux and calf venous pump function was largely similar. Among seven limbs with severe preoperative venous obstruction (grade III or IV), five (70%) had significantly improved obstructive grading, presumably as a result of elimination of reflux flow.

CONCLUSIONS

The traditional admonition against removal of secondary varices should be reexamined. Saphenectomy may be indicated in postthrombotic syndrome with mixed obstruction/reflux. The procedure is clinically well tolerated and without malsequelae. Improvement in reflux parameters without significant worsening of objective measures of obstruction is documented in this group.

Axial transformation of the profunda femoris vein

PURPOSE

To highlight a special subset of cases of venous stasis in which the profunda femoris vein enlarges to a variable extent (axial transformation) to compensate for severe postthrombotic changes in the accompanying superficial femoral vein.

METHODS

Among 500 consecutively treated patients with severe venous stasis, 57 patients had axial transformation of the profunda femoris vein. Venous obstruction and reflux were assessed by means of arm-foot pressure differential, ambulatory venous pressure measurement, air plethysmography, and duplex examination. Ascending and descending venograms also were obtained. A variety of valve reconstruction techniques were useful in correcting reflux in the enlarged profunda femoris vein and the companion postthrombotic superficial femoral vein.

RESULTS

In 55% of patients the profunda femoris vein was larger than normal and provided partial outflow from the leg through a profunda-popliteal connection, but the superficial femoral vein was still the dominant outflow tract (grades I and II). In 36% of patients the profunda femoris was the dominant outflow tract from the leg, and in another 9% it was the sole axial outflow tract (grades III and IV). The skin changes of advanced venous stasis were present among 92% of patients and frank ulceration among 88%. Antireflux operations on the profunda femoris vein and companion superficial femoral vein, including ligation and division in some instances, were well tolerated. Despite a postthrombotic cause, obstruction did not worsen after surgical treatment, and reflux improved according to most laboratory measurements. Complete ulcer healing was obtained with the surgical techniques described. The actuarial recurrence-free survival rates were 90% 1 year and 66% 5 years after treatment.

CONCLUSION

Axial transformation of the profunda femoris vein is present in a subset of instances in which severe postthrombotic changes are present in the companion superficial femoral vein. Profunda femoris reflux is invariably present in these instances because of compensatory dilatation and enlargement of this vessel. Simultaneous valve repair of the axially transformed profunda femoris vein and companion superficial femoral vein to abolish reflux yields excellent long-term results and healing of stasis ulceration.

Tube collapse and valve closure in ambulatory venous pressure regulation: studies with a mechanical model

PURPOSE

To determine the role of valve closure and column segmentation in ambulatory venous pressure regulation.

METHODS

Using a mechanical model consisting of a graduated adjustable valve and a collapsible tube, we studied the differential effects of valve closure and tube collapse on venous pressure regulation. By utilizing materials with differing wall properties for the infravalvular tube, the influence of wall property changes on tube function and pressure regulation was explored.

RESULTS

Valve closure, per se, does not cause venous pressure reduction. Collapse of the tube below the valve is the primary pressure regulatory mechanism. The nonlinear volume-pressure relationship that exists in infravalvular tubes confers significant buffering properties to the collapsible tube, which tends to retain a near-constant pressure for a wide range of ejection fractions, residual tube volumes, and valve leaks. Changes in tube wall property affect this buffering action, at both the low and high ends of the physiological venous pressure range.

CONCLUSIONS

The valve and the infravalvular venous segment should be considered together in venous pressure regulation. Tube collapse of the segment below the valve is the primary pressure regulatory mechanism. An understanding of the hydrodynamic principles involved in pressure regulation derived from this model will provide the basis for construction of more complex models to explore clinical physiology and dysfunction.

Where angels fear to tread? Mapping women and men in India

"The authors have produced the ¿Atlas of Women and Men in India', using material from the 1991 Census, mainly at district level. The Atlas may be unacceptable to Indian geographers because it seeks to question the authority of numerical data and of maps, and to Western geographers because this is ¿mapping before we understand the process'. The authors introduce maps of the sex ratio in India and explore through a map of changes in the sex ratio 1981-91 some numerical, analytical, and ethical problems of such mapping. The Indian feminist activists consulted want the Atlas for advocacy: does this justify its production?"

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.

Technical options in venous valve reconstruction

PURPOSE

Several modifications and details of techniques that were found useful in venous valve reconstruction are described. Related technical outcome data are also presented.

METHODS

Five hundred eighty-two valve segments were reconstructed in 347 limbs using a variety of different techniques.

RESULTS

Intraoperative valve competence was achieved in 86% of 347 limbs. The incidence of technical stenosis was 4%, thrombosis of repair <1%, loss due to hematoma/infection <1%, and operative mortality 0%. Postoperative duplex competence was achieved fully in 78% and partially in 16%; 6% remained refluxive. Rapid postoperative healing of stasis ulcer occurred in 93%.

CONCLUSIONS

The expanded variety of technical options in valve reconstruction allows optimization for the individual patient. Regardless of pathology, a functional venous valve can be reconstructed in most patients utilizing one of the described techniques.

Durability of venous valve reconstruction techniques for "primary" and postthrombotic reflux

PURPOSE

The durability of the variety of valve reconstruction techniques in "primary" reflux and postthrombotic reflux was studied.

METHODS

A total of 423 valve repairs in 235 patients with a follow-up period ranging from 1 to 12 years were analyzed. End points for assessment consisted of ulcer recurrence and Doppler competence in serial duplex examination. Multivariate analysis with Cox proportional hazards model was used.

RESULTS

Ulcer-free survival curves were similar for "primary" and postthrombotic reflux. No significant difference in ulcer recurrence was seen regardless of the technique used. Different results were obtained when valve competence instead of ulcer recurrence was used for assessment of durability. Reconstructions in "primary" reflux were more durable than those in postthrombotic reflux. Durability differences were also noted among different techniques. A cohort of posterior tibial repairs proved extraordinarily durable (0 failures in 23 repairs).

CONCLUSION

Valve reconstruction in postthrombotic reflux can yield clinical results similar to those in "primary" reflux. Although any of the several described techniques can produce similar clinical results, Doppler competence suggests the following order for choice of procedures: (1) internal valvuloplasty, (2) prosthetic sleeve in situ, (3) external valvuloplasty, and (4) axillary vein transfer.

Light and electron microscopic observations of epithelial shedding in stored canine small intestine

Simple cold storage of canine small intestine is accompanied by ischemic damage to the intestinal mucosa. Progression of damage observed during cold storage is unique and has not been observed with other organs. The mucosal damage begins within 15 min after the onset of the storage, with progressive involvement of the gut as the storage period lengthens. Cytoplasmic blebs develop from the base of the epithelial cells and detach the epithelium from the basal lamina. While the process begins uniformly along the length of the villus, separation of the epithelium occurs first at the villus tip. The epithelium, which is shed into the intestinal lumen, is otherwise undamaged. Blebbing occurs in enteroendocrine and goblet cells and is not restricted to enterocytes. Early blebs occur in proximity to mucosal mast cells and subepithelial nerves. Tissue damage in cold is possibly related to enzymes that are still active at storage temperatures.

The pressure/volume relationship of the calf: a measurement of vein compliance?

OBJECTIVES

The role of compliance changes in the patho-physiology of venous disease is not well known mainly because of difficulty to measure compliance of veins in situ. This study suggests a method to determine the calf pressure/volume relationship by utilizing venous occlusion plethysmography combined with dorsal vein pressure.

DESIGN

Comparison between two techniques of measuring calf pressure/volume relationship using air plethysmography with validation against popliteal vein diameter changes detected by duplex ultrasound. SETTING Vascular laboratory.

MATERIALS

In 6 normal and 6 radiographically confirmed post-thrombotic lower limbs, the calf pressure/volume relationship was determined. The dorsal vein pressure was continuously recorded. Simultaneously calf volume changes were obtained by an air plethysmograph during venous occlusion plethysmography (outflow slope coefficient) and fractionated tilting of the subject from erect to supine position (volume at 40 mmHg). During the tilt, sagittal diameter of the popliteal vein was measured (% change/mmHg = distensibility).

RESULTS

The outflow pressure/volume slope coefficient correlated significantly with the volume at 40 mmHg during tilt maneuver (r = 0.92) and the popliteal vein distensibility (r = 0.86). Variations in arterial inflow, venous outflow obstruction, or reflux did not affect the occlusion plethysmographic method. Plethysmographic changes related directly to venous volume changes, i.e. vein expansion suggesting that the pressure/volume relationship described vein compliance.

CONCLUSION

The result show a direct relationship between the pressure/volume curve of the calf and deep vein distention. Shifts of the pressure/volume curve are likely to be mainly caused by vein wall changes, but other factors (e.g. condition of surrounding tissue, reduced venous volume) may also contribute and this needs further investigation.

Compliance of the normal and post-thrombotic calf

OBJECTIVE

In addition to degree of outflow obstruction and reflux and poor calf muscle pump function, vein wall compliance changes are important in understanding pathophysiology of venous disease. This study compares the pressure/volume relationship in post-thrombotic and healthy legs.

EXPERIMENTAL DESIGN

Prospective and comparative study.

SETTING

Vascular laboratory.

PARTICIPANTS

Investigations were performed on 24 apparently normal legs and 30 post-thrombotic limbs as confirmed by phlebography.

METHOD

Dorsal vein pressure and absolute calf volume decrease were recorded simultaneously during outflow form the leg after release of the cuff during venous occlusion air-plethysmography with and without reactive hyperemia. The slope of the pressure/volume outflow curve was calculated. In addition, the distensibility (= collapsibility) was determined as % volume decrease/mmHg. The popliteal and femoral vein diameters were measured in supine and erect position by ultrasound.

RESULTS

With and without induced hyperemia the mean slope coefficients of post-thrombotic legs were significantly higher (0.52 +/- 0.22 and 0.53 +/- 0.18) than in normal (0.15 +/- 0.10 and 0.29 +/- 0.11), i.e., the curve steeper since the calf was stiffer, less compliant. The degree of outflow obstruction and severity of skin changes did not affect the slope measurement substantially. Collapsibility during venous outflow was significantly less in post-thrombotic legs. The post-thrombotic veins were less distended on standing.

CONCLUSIONS

Post-thrombotic calves are less compliant than normal legs mainly due to less compliance of the vein wall, although theoretically reduced venous volume may contribute.

Chronic venous insufficiency

Chronic venous insufficiency has been known as a distinct pathologic entity at least since the time of Hippocrates, yet many pathologic features of this common ailment remain obscure. A recent resurgence of investigative effort in chronic venous insufficiency has occurred, spurred by the development of valve reconstruction surgery. The advent of newer diagnostic devices and techniques such as duplex scan and air plethysmography allow for a more detailed examination of the venous system than was possible previously.

Persistent sciatic artery: embryology, pathology, and treatment

PURPOSE

The purpose of this article is to describe the embryologic development and anomalous persistence of the sciatic artery, pathologic changes that may occur in the persistent sciatic artery, and management of complications related to these pathologic changes.

METHODS

Two patients with persistence of the sciatic artery treated in the authors' experience are reported. In addition, the computerized data base of the University of Mississippi Medical Center was searched for patients with other lower extremity arterial aneurysms, and their records were reviewed for possible aneurysm of a persistent sciatic artery. A review of the literature was undertaken to determine the embryologic development of the persistent sciatic artery, the pathologic changes that have been observed in the sciatic artery, clinical findings associated with these pathologic changes, and methods of treatment.

RESULTS

Two patients with persistence of the sciatic artery were treated by the authors. No other cases were identified in 43 patients with 66 lower extremity aneurysms treated at our institution. The first patient presented with acute lower extremity ischemia caused by thrombosis of a sciatic artery aneurysm and was treated successfully with intraarterial thrombolytic therapy followed by interposition graft repair. In the second case an incidental unilateral persistent sciatic artery was identified in a patient with bilateral Buerger's disease presenting with digital gangrene of the contralateral extremity in whom below-knee amputation was eventually required. Bilateral tibial artery occlusion was observed on arteriography. Histologic examination of the amputated limb confirmed findings typical of Buerger's disease, and no microemboli were seen.

DISCUSSION

The sciatic artery is a continuation of the internal iliac artery and is the primary blood supply to the lower limb bud during early fetal development. The sciatic artery normally involutes during fetal development, but remnants persist as the popliteal and peroneal arteries after the superficial femoral artery develops and establishes continuity with the popliteal artery. Persistence of the sciatic artery as the major blood supply to the lower extremity in adults is a rare vascular anomaly that may be of surgical significance. Failure to appreciate the persistent sciatic artery as the major inflow into the lower extremity may lead to inappropriate bypass of apparent occlusive disease of the superficial femoral artery. The persistent sciatic artery is also frequently aneurysmal, which may cause critical limb ischemia resulting from thrombosis or embolization of aneurysm thrombus. Options for vascular reconstruction include interposition graft replacement and standard femoropopliteal bypass grafting if the common femoral artery is sufficiently developed to provide adequate inflow. As with other peripheral arterial aneurysms resulting in thrombosis and extensive distal arterial embolization and thrombosis, intraarterial thrombolytic therapy may be useful in selected cases before definitive surgical revascularization.