Subfascial Endoscopic Perforating Vein Surgery (SEPS) for the Treatment of Venous Ulcers
V enous ulcers are a significant health problem, affecting 2% of the population in Western countries.1 These ulcerations are disabling due to their chronicity, tendency to become infected, and associated pain. Often, patients are affected by venous ulcers during their most productive years of life. Treatment involves significant amounts of medical resources, placing a substantial financial burden on modern healthcare systems.2-4
Venous ulcers typically form posterior to the medial malleolus (see Figure 1). They frequently present in an area of thickened skin and soft tissue described as lipodermatosclerosis. Hemosiderin deposition, a brawny brown pigmentation of the skin, often is seen in a circumferential pattern between the medial malleolus and the upper part of the calf. This distribution of abnormal pigmentation and thickening of the skin and soft tissue is called gaiter distribution. The skin is frequently friable and scaly, leading to venous eczema (see Figure 2).
The etiology of venous ulcers is related to venous hypertension in the lower extremity; specifically, ambulatory venous pressure (AVP) is significantly related to the prevalence of ulcers. Ambulatory venous pressure is typically measured by cannulating a dorsal foot vein and transducing a resting venous pressure. The pressure is then measured after muscle contractions (toe raises) with a subsequent fall in pressure as the veins empty. If the AVP is consistently >90 mm Hg, venous ulceration is inevitable. Similarly, ulcers are rare if patients have AVPs that measure 5 This association of AVP with occurrence of ulceration is maintained regardless of the specific abnormality in the vein. Increased AVPs can occur as a result of valvular incompetence, chronic obstruction (which usually occurs after a thrombotic event), or a combination of these two factors.
The lower extremity venous system is divided into superficial and deep systems. The deep venous system is located immediately adjacent to the arterial system. The names for these arteries and veins are shared (ie, for every artery there is a pair of deep veins). They include the superficial femoral, popliteal, posterior tibial, anterior tibial, and peroneal veins. The superficial system includes the greater and lesser saphenous veins. The lesser saphenous vein courses between the gastrocnemii muscles in the lower calf, typically entering the deep system in the popliteal fossa. The greater saphenous vein originates at the ankle. It follows a course through the medial aspect of the leg all the way into the upper thigh. At that point, the vein courses in the lateral direction and eventually joins the common femoral vein. Both of these named superficial veins have significant tributaries. One of these branches, the posterior arch vein, courses in the posterior aspect of the calf and joins the greater saphenous vein below the knee. Perforating veins are short-segment veins that join the superficial system to the deep system.6 They are named for the fact that they perforate the muscle fascia. Cockett perforating veins connect the posterior arch vein with the posterior tibial veins.7 Under normal circumstances, they provide a conduit for blood flow from the superficial system to the deep system. Perforating veins also have valves that prevent reflux. When these veins become incompetent, they allow significant reflux into the superficial system. These incompetent perforating veins are associated with both location and prevalence of venous ulceration. Boyd perforating veins are located between the upper calf and lower thigh8 and Dodd’s perforators are located in the thigh.
History of Perforator Ligation Surgery
In 1938, Linton9 described a technique (which came to bear his name) for the treatment of venous ulcers. This involved a large incision across the calf and formation of a skin, soft tissue, and fascial flap. Once the flap was elevated, perforating veins were identified and could be ligated. The procedure is effective in healing venous ulcers but has a high wound infection rate (50%), resulting in significant morbidity.10
Modification of Linton’s original open procedure has been reported with some improvement in wound infection rates.8 In 1985, Hauer11 published his efforts using an endoscopic approach to ligating Cockett perforating veins. The endoscopic approach allows the surgeon to incise through normal skin located in more superior portions of the lower leg. In 1997, Pierik et al,10 in a randomized prospective trial using endoscopic techniques, demonstrated no wound infections using endoscopic approaches but a 53% wound infection rate in patients randomized to the traditional open perforating vein ligation.
Subfascial Endoscopic Perforating Vein Surgery (SEPS)
Procedure. A tourniquet is placed above the knee and an Esmarch band is placed tightly around the lower extremity to empty the blood from the surgical site. The tourniquet is inflated to supra systolic blood pressure (usually 300 mm Hg). An incision is made one-hand’s width below the tibial prominence and two-finger’s breadth posterior to the anterior border of the tibia. This provides access for the camera and carbon dioxide insufflation. A large balloon trocar is placed through this incision into the subfascial plane (see Figure 3) and filled with 180 cc of saline to expand the space. The balloon is emptied and removed. Carbon dioxide insufflation is started through the trocar, maintaining a pressure of 30 mm Hg to keep the subfascial space expanded and to allow visualization of the structures. Frequently, a second incision is placed inferior and posterior to the first, allowing insertion of the instruments that perform the vein ligation (either cautery hook or clip applier and scissors). The camera follows the instruments in a caudal direction and perforating veins are identified traversing the subfascial space. The veins are divided and the instruments are removed. The incisions then are closed in two layers and a pressure dressing is applied before the tourniquet is released.
The procedure is frequently performed in an ambulatory care setting. The pressure dressing is left in place for 2 to 5 days. Lower extremity activity is limited for 5 to 7 days. Full recovery is usually attained in 2 weeks. The incidence of complications after the SEPS procedure range from 0% to 9%, with hematoma (9%), transient neuralgia (7% paresthesia, hypesthesia), and wound infections (6%) accounting for the majority of complications. Deep venous thrombosis has been reported after the procedure.12
Current results. Numerous retrospective and prospective trials have demonstrated that endoscopic techniques for the ligation of incompetent perforating veins are safe and effective.13-16 In 1999, Gloviczki et al17 reported the preliminary results of the North American Subfascial Endoscopic Perforator Surgery Registry. In this initial evaluation, 148 SEPS procedures were performed in 17 centers across the US and Canada. Cumulative ulcer healing after SEPS was 88% in 1 year; the median time for ulcer healing was 54 days. The cumulative ulcer recurrence rates at 1 and 2 years were 16% and 28%, respectively. The study by Pierik et al10 in 1997 is the only prospective, randomized trial comparing the SEPS procedure with the open Linton procedure to date — the trial demonstrated an unacceptably high wound complication rate associated with the open procedure. Recently, the long-term data from this study, which was terminated prematurely, demonstrated no statistically significant difference in overall ulcer healing rate (95% versus 100%) or recurrence rate (12% versus 11%) between the SEPS procedure and the Linton procedures.16 In a retrospective meta-analysis of the surgical management of venous ulcers using the SEPS procedure, Tenbrook et al12 found a similar recurrence rate of 13% with a mean time of 21 months for 1,140 treated limbs. The authors further identified several risk factors for recurrence, including postoperative incompetent perforators, obstruction, secondary causes for the venous insufficiency, and ulcers greater than 2 cm.
A number of studies document significant improvement in hemodynamics following the SEPS procedure.18–20 In addition, these hemodynamic results highlight an important aspect of the SEPS procedure. Improved outcomes, including improved hemodynamic measurements, are significantly better when superficial venous reflux has been treated, either before or at the same time of the SEPS procedure.20 In cases where the incompetent saphenous vein is left without treatment, outcomes are significantly worse. Typically, this occurs in patients with a post-thrombotic syndrome where ablation of the saphenous vein may significantly worsen leg drainage because the deep system is obstructed. In this clinical scenario, most clinicians elect to leave the incompetent saphenous vein without treatment. Unfortunately, these patients have a significantly higher rate of initial ulcer persistence or recurrence.
Over the past century, clinicians have developed a better understanding of chronic venous insufficiency, which has led to more effective treatments. Compared to conservative management with compression treatment, exercise, and elevation, the SEPS procedure demonstrates overall improved wound healing rates (>95% versus 65%) and decreased incidence of ulcer recurrence (13% versus 28%).21 While SEPS is an invasive procedure and has a higher incidence of associated complications, the rate of complications is
The major advantage of the SEPS procedure is the ability to create incisions that are distant from the venous ulceration and lipodermatosclerosis that occurs with chronic venous insufficiency. This advancement is responsible for dramatic improvement in wound complications related to the ligation of perforating veins. However, further advances in the size of the incision and in the technical ease of the procedure could be realized if small endoscopic instruments were available to perform this procedure. Cameras and trocars measuring 5 mm are available for other endoscopic procedures and their use in this application would significantly reduce the incision size required. In addition, because subfascial space is limited, smaller instruments would improve the ease with which this procedure is performed, disrupt less tissue, reduce postoperative discomfort, and shorten recovery time.
Despite the safety and efficacy of the SEPS procedure, this intervention is probably under-utilized, given the significant prevalence of venous ulceration. Review of the literature demonstrates a significant number of single institution reports. Most of these reports include fewer than 40 treated limbs.10,19,20,22 Several explanations are possible. First, patients with venous ulcers are not commonly referred to surgeons for treatment; rather, they are frequently seen by wound care specialists or dermatologists. Similarly, patients with deep venous thrombosis are treated by their primary care physicians and may not be evaluated for post-thrombotic syndrome by vascular specialists. In addition, substantial recurrence rates lead to frustration with operative interventions for venous ulcerations. Continued clinical research efforts should be directed at clearly defining the etiology of recurrent ulcerations and careful patient selection to derive the maximum benefits from these interventions.
Although a clear relationship exists between increased AVP and the occurrence of venous ulcerations, the exact mechanism of this relationship is still not known. Many possible etiologies have been explored. Currently, an immunologic disturbance is thought to be the missing link between increased AVP and skin breakdown.23 Once the cascade of events between the onset of increased AVP and skin ulceration is defined, further non-invasive methods may be available for treatment of metabolic derangement.
Subfascial endoscopic perforating vein surgery is a safe and effective method for treating incompetent perforating veins. Performed as an outpatient procedure, it is an important adjunct to ablation of superficial venous incompetence and the overall treatment of venous ulcers. This procedure utilizes minimally invasive endoscopic techniques that have low morbidity. Primary wound healing rates are reported to be as high as 88% in the first few months following surgery. Recurrence of venous ulcers is highest among patients with post-thrombotic syndrome and patients not treated with ablation of superficial venous incompetence. Future research efforts hopefully will define the exact mechanism of skin breakdown for these patients. In addition, subtle improvements in technique will help make the SEPS procedure more valuable as an important intervention in the treatment of these patients.