Treatment of chronic venous insufficiency (CVI) has largely focused on reflux. Minimally-invasive techniques to address superficial and perforator reflux have evolved, but correction of deep reflux continues to be challenging. The advent of intravascular ultrasound (IVUS) scan and minimally invasive venous stent technology have renewed interest in the obstructive component in CVI pathophysiology. The aim of this study is to assess stent-related and clinical outcomes following treatment by iliac venous stenting alone in limbs with a combination of iliac vein obstruction and deep venous reflux.
A total of 528 limbs in 504 patients, ranging in age from 15 to 87, underwent IVUS-guided iliac vein stent placement to correct obstruction over an 11-year period. The etiology of obstruction was nonthrombotic in 196 (37%), post-thrombotic in 285 (54%) limbs, and combined in 47 (9%). Clinical severity class of CEAP was C3 in 44%, C4,5 in 27%, and C6in 25% of stented limbs. Deep venous reflux was present in all limbs, associated with superficial and/or perforator reflux in 69%. Reflux was severe in 309/528 (59%) limbs (reflux multisegment score ≥3) and 224/528 (42%) limbs had axial reflux. Venography and other functional tests had poor diagnostic sensitivity to detect obstruction, which was ultimately diagnosed by IVUS. The IVUS-guided iliac vein stenting was the only procedure performed and the associated reflux was left uncorrected.
There was no mortality; morbidity was minor. Cumulative secondary stent patency was 88% at 5 years; no stent occlusions occurred in nonthrombotic limbs. Cumulative rates of limbs with healed active ulcers, freedom of ulcer recurrence in legs with healed ulcers (C5), and freedom from leg dermatitis at 5 years were 54%, 88%, and 81%, respectively. Cumulative rate of substantial improvement of pain and swelling at 5 years was 78% and 55%, respectively. Quality of life improved significantly. Reflux parameters did not deteriorate after stenting.
Iliac venous stenting alone is sufficient to control symptoms in the majority of patients with combined outflow obstruction and deep reflux. Partial correction of the pathophysiology in limbs with multisystem or multilevel disease can provide substantial symptom relief. Percutaneous stent technology in concert with other minimally-invasive techniques to address superficial and/or perforator reflux offers such partial correction in limbs with advanced CVI and complex venous pathology. Open correction of obstruction or reflux is now required only infrequently as a “last resort”.
Reflux is considered the dominant pathology in chronic venous insufficiency (CVI). The diagnosis and treatment of reflux has been the main focus of managing symptomatic patients with CVI for over a century. It has, however, been recognized that obstruction alone may cause symptoms in a small subset of patients with CVI with post-thrombotic limbs1 or those with primary disease (May-Thurner syndrome). Venovenous bypass was the standard in treating the obstruction in such cases. With the use of intravascular ultrasound scans and other modern imaging technologies, it is now known that morphologic obstruction of the iliac veins is ubiquitous and can be demonstrated to be present in the majority of patients with CVI alone or in association with reflux. The pathophysiologic significance of this finding is unclear. Whether or not it is necessary to correct this iliac vein obstruction in limbs with combined obstruction/reflux is unknown. The indications for intervention are not well defined. The advent of percutaneous stent technology allows for a relatively simple way to correct iliac vein obstructions, and endovenous stenting has largely replaced Palma bypass with excellent stent patency and clinical outcome. Stenting was initially performed in patients with CVI with isolated iliac vein obstruction without associated reflux. After having established its safety and efficacy, stenting was performed as the initial treatment of patients with combined obstruction and deep venous reflux. The intention was to later perform valve reconstruction with the aim of achieving better symptom relief than with valve reconstruction alone. Surprisingly, symptom relief with initial iliac vein stenting was so effective that additional valve repair was found to be unnecessary in the majority of patients. The aim of this study is to assess stent-related and clinical outcomes following treatment by iliac venous stenting alone in limbs with a combination of iliac vein obstruction and deep venous reflux. The reflux remained untreated.
Patients and methods
Iliac vein stenting was performed in a total of 1640 limbs during 1997-2008 (11 years). Of these, 1112 limbs were excluded from this analysis because deep reflux was absent or other procedures were carried out concurrent with stent placement, preventing stent-specific outcome analysis: limbs with intravascular ultrasound (IVUS)-detected iliac vein stenosis with no associated reflux (n = 445); limbs with associated reflux confined to the superficial system (n = 255); limbs with concurrent saphenous ablation performed along with the stenting (n = 366); and limbs with incomplete information regarding concomitant reflux (n = 46). Current analysis pertains to the remaining 528 stented limbs (32%) with deep venous reflux alone (n = 172) or in combination with untreated superficial or perforator reflux (n = 356). Iliac vein stenting was the sole corrective procedure and the reflux component was not treated.
Indications for iliac vein stenting
Patients with significant symptoms of pain (visual analog scale [VAS] ≥5/10), marked swelling, stasis skin changes including ulcers, or combinations of signs and symptoms unresponsive to conservative measures were considered for iliac vein stenting. As a tertiary referral center, most patients had been under the care of other physicians before referral for persistent symptoms and treated conservatively, including compression therapy.
The study endpoint of legs with stasis ulceration was complete epithelialization. Primary nonhealing ulcers were marked as such and censored at 4 months. Any breakdown of an ulcer after healing was considered a recurrence. The degree of pain was evaluated perioperatively using a VAS from 0-10, wherein 10 is the most severe pain. Swelling was assessed as grade 0 (absent); grade 1 (pitting, not obvious); grade 2 (visible ankle edema); and grade 3 (massive, encompassing the entire leg). Patients were asked to fill out a health-related quality of life (QoL) questionnaire (CIVIQ) assessing subjective leg pain, leg symptoms affecting sleep, work, morale, and social activities before intervention, and again at each subsequent postoperative visit. The CIVIQ form has a proven specificity and relevance to chronic venous disease. The last available clinical evaluation was used in postoperative outcome analysis.
Preoperative investigations included duplex examination, arm/foot venous pressure test, ambulatory venous pressure (AVP) measurement, percentage drop, venous filling time (VFT), air plethysmography (venous filling index [VFI90, mL/second]), and ascending and transfemoral venography with exercise femoral pressure measurements. Tests were performed through the same venous access, if possible, to minimize venipunctures. An IVUS examination was the definitive diagnostic test and was also essential in guiding the stent placement. IVUS makes it possible to accurately identify the degree of stenosis and extent of the lesion by using incorporated software to use planimetry to measure lumen size and allows calculation of the cross-cut area stenosis. Intraluminal lesions, outside compression, and wall thickness can be better shown by IVUS than venography