Techniques used for open iliocaval venous reconstruction

INTRODUCTION — Open surgical reconstruction to restore lower extremity venous outflow might be necessary when endovenous treatments are not anatomically desirable or feasible, or prior attempts at endovenous revascularization have failed. Iliac venous obstruction with or without inferior vena cava involvement, regardless of the underlying etiology, is associated with significant worsening of health-related quality of life and chronic symptoms (eg, swelling, skin discoloration, limb pain, venous claudication, venous ulcers) [1].

Open surgical venous reconstruction of the lower extremity is reviewed. General management issues and endovascular therapies used to manage venous obstruction are reviewed separately. (See "Overview of iliocaval venous obstruction" and "Endovenous intervention for iliocaval venous obstruction".)

POTENTIAL CANDIDATES — For chronic venous obstruction, the first line of treatment is generally limb elevation and extremity compression; however, its utilization may not be advantageous because of the proximal nature of venous obstruction, and it often does not provide sufficient relief [2-4]. Endovascular intervention has been increasingly used to restore venous outflow but is not immune from recurrent stenosis, stent fracture, migration, or collapse. Increasing use of iliocaval stenting has been associated with a noticeable increase in stent occlusion with recurrence of symptoms. These complications have motivated renewed interest and revival of past knowledge on available options for open surgical intervention. In addition, for some patients, endovascular intervention is not an option (eg, vascular anomalies, venous ligation).

Open surgical reconstruction may be needed to manage problems arising from the following situations:

●Recurrent obstruction following iliocaval stenting or unsuccessful stent placement (eg, pelvic irradiation and scarring) [5,6]. (See "Overview of iliocaval venous obstruction".)

●Resection of the inferior vena cava (IVC) or iliac veins, which might be required to achieve goals of oncologic surgery for primary tumor (eg, leiomyosarcoma) or secondary tumor involvement (eg, retroperitoneal sarcoma) [7,8]. (See "Surgical resection of retroperitoneal sarcoma".)

●Thrombotic obstruction following IVC filter placement or caval interruption for venous thromboprophylaxis [9]. (See "Placement of vena cava filters and their complications", section on 'Complications'.)

●Following traumatic injury to the vena cava, iliac veins, or femoral veins. Venous ligation may be necessary for hemodynamically unstable patients as a part of a damage control approach and with subsequent venous reconstruction [10]. Iatrogenic venous injury can also prompt the need for open reconstruction (eg, during anterior exposure of the spine [11]). (See "Abdominal vascular injury", section on 'Abdominal venous injury'.)

●IVC reconstruction may be necessary to complete orthotopic liver transplantation to re-establish the portal and hepatic venous outflow.

Good candidates for venous reconstruction include low-risk surgical patients without significant reflux in the femoropopliteal veins, an unaltered external iliac or common femoral vein suitable for a proximal anastomosis, and a normal vena cava or a contralateral iliac vein available for outflow [12].

PREOPERATIVE EVALUATION — Prior to open venous reconstruction, the patient should undergo complete history and physical examination. Prior surgical interventions should be noted, particularly venous interventions including venous ablation procedures, any history of venous angioplasty or stenting, or prior reconstructions using lower extremity veins.

To evaluate venous anatomy, bilateral lower extremity venous duplex, including evaluation for superficial or deep venous reflux, and vein mapping are required. Cross-sectional imaging, such as computed tomography (CT) angiography with venous phase or magnetic resonance (MR) imaging adds important technical information including objectively characterizing iliocaval segment, identifying any extrinsic compression or oncologic pathology, and also identifying significant venous collaterals that should be preserved during surgical dissection. Lastly, it can guide the selection of the size of conduit grafts needed for iliocaval reconstruction.

Prior to open surgical reconstruction, we perform contrast venography for a detailed assessment of the venous anatomy of the leg, pelvis, and abdomen. Hemodynamically significant venous obstruction is confirmed by measurement of a pressure gradient >5 mmHg measured from distal to proximal of the obstruction [13]. Some clinicians have used doubling of the resting femoral pressure after calf exercise as another objective means of determining the significance of venous obstruction [14].

APPROACH TO VENOUS RECONSTRUCTION — The approach to venous revascularization depends on the level of obstruction, availability of conduit, and whether the occlusion is unilateral or bilateral.

Surgical options — Surgical options differ somewhat depending on whether venous occlusion is unilateral or bilateral. For patients with extensive iliocaval venous occlusion with bilateral or unilateral common femoral venous occlusion, hybrid reconstruction is sometimes used. (See "Endovenous intervention for iliocaval venous obstruction" and 'Open venous patch angioplasty' below.)

Unilateral occlusion — Unilateral occlusion is likely to be encountered in cases of traumatic ligation of iliac veins in which case a femoroiliac or femorofemoral venous reconstruction may be offered, or if iliac vein was removed as part of oncologic resection, an iliocaval bypass may be offered. (See 'Femoro-femoral venous bypass' below and 'Femoroiliac or iliocaval bypass' below.)

Bilateral occlusion — Bilateral occlusion is likely related to multiple failed iliac stents, chronic iliocaval occlusion from inferior vena cava (IVC) filter, or oncologic pathology. The proximal extent of occlusion is commonly to the level of renal veins and to both common iliac veins distally, and bifemoral-caval bypass may be offered. (See 'Bifemoral-caval bypass' below.)

Conduit options and selection — Conduits for venous reconstruction can be autologous or prosthetic. Most clinical practice is based on institutional experience with venous reconstruction, and evidence is still lacking on long-term durability and patency. Conduits are generally:

●Autologous great saphenous vein (GSV) graft

●Autologous spiral saphenous vein graft

●Externally supported expanded polytetrafluoroethylene (ePTFE) grafts [15,16]

When selecting a conduit for venous reconstruction, factors important to selecting a conduit for venous reconstruction include the necessary diameter (often large), the length of the venous lesion, and the desire to maintain venous collateral flow. Because of tendency for kinking and compression associated with vein conduits, externally supported ePTFE is commonly used. Even when GSV is used as a crossover graft, many respected authorities report passing the vein inside an ePTFE graft to minimize the possibility of kinking or compression [13,17].

Another potential benefit to ePTFE for iliocaval venous reconstruction is the preservation of lower extremity collateral venous flow. In the author's opinion, every effort should be made to preserve the GSV and avoid ligation of any venous collateral circulation in the groin during iliocaval reconstruction, particularly when associated with chronic distal (femoropopliteal) vein occlusions. Distal obstructions are often better tolerated because of parallel venous drainage. However, harvesting one or both saphenous veins would disturb this parallel system, albeit if the outflow obstruction is corrected, this might not be felt. However, if the outflow is reobstructed, the patient may have worsening clinical symptoms.

For autologous reconstruction of the IVC, a 12 to 14 diameter vein is needed. This size is often not available for veins, but an appropriately sized conduit can be made by creating a spiral graft using available GSV. To create a spiral vein graft, a longitudinal incision is made in the medial thigh and leg, and the GSV is removed from its bed and opened along its length [18]. The vein valves are removed, and the vein is sutured to itself in a spiral fashion. Usually, this can be performed by wrapping the opened vein onto a 36 Fr chest tube and suturing the margins of the vein together with 6-0 or 5-0 polypropylene suture.

TECHNIQUES

Incisions and venous exposure

●Groin – A groin incision is used to expose the common femoral vein (CFV), deep femoral vein (DFV), and the origin of the great saphenous vein (GSV). Either a transverse or longitudinal incision can be used; ultrasound guidance facilitates the exposure. The incision is extended through the subcutaneous tissue to the femoral sheath, which is incised longitudinally. The CFV is visible medial to the common femoral artery.

●Retroperitoneal – To expose the iliac veins, a limited retroperitoneal flank incision (ie, renal transplant incision) can be used on the right or on the left.

For right-sided iliac venous occlusion, the right retroperitoneum is entered by dividing the avascular line of Toldt and a right medial visceral rotation used to expose the inferior vena cava (IVC). A Kocher maneuver is rarely needed, as we aim to stay below the renal veins to clamp the IVC.

Exposure of right external iliac vein is gained by dissecting the right external iliac artery and passing a vessel loop to reflect the artery laterally. A limited left visceral rotation exposes the left external iliac vein, which can be done in conjunction with a groin incision for a femoroiliac bypass, or together with a transperitoneal IVC exposure for an iliocaval bypass. Exposure of the common iliac veins is rarely done given that the veins are commonly occluded in iliocaval obstruction (and therefore bypassed), and the dissection is technically difficult due to the overlying common iliac arteries. In addition, collateral veins are usually well-developed, and inadvertent injury to them can cause serious bleeding.

●Transperitoneal – A transperitoneal midline approach with right medial visceral rotation can also be used to expose the IVC. For more proximal exposure of the IVC, adding a Kocher maneuver exposes the IVC to its retrohepatic termination.

If suprarenal caval exposure is required, the suprarenal segment of IVC can be exposed by retracting the left and caudate lobes of the liver to the right to expose the left border of the retrohepatic segment of IVC. Separation of the duodenum from the pancreas gives access to its intrahepatic segment. The entire suprarenal segment of the vein can thus be exposed.

Open venous patch angioplasty — For open venous angioplasty, once the selected vein is exposed and proximal and distal control is obtained, a longitudinal venotomy is made through the area of obstruction. A vein or prosthetic patch (eg, xenograft [bovine], polyester, expanded polytetrafluoroethylene [ePTFE]) is fashioned and sutured into place using continuous, permanent monofilament suture. The wound is closed in layers.

For a hybrid approach, endovascular stenting of iliocaval occlusive disease can be combined with endophlebectomy and patch angioplasty. Some surgeons perform endophlebectomy with patch angioplasty and then cannulate the patch and perform the angioplasty/stenting extending the distal end of the stent into the apex of the surgical repair. While the iliac artery may be divided to repair an acute iliac vein injury, this is mostly unnecessary.

Venous bypass techniques

Femoro-femoral venous bypass — Femoral-to-femoral venous bypass (ie, the Palma procedure) uses a transposed contralateral saphenous vein for unilateral iliac vein obstruction. An adequate diameter and length of vein is required. This procedure has been used for over seven decades since Palma and Esperson reported their first successful cross-femoral venous bypass in 1960 [17,19-25]. Since that time, the Palma procedure has been used as an effective treatment for chronic venous symptoms in the setting of ipsilateral iliac vein obstruction, particularly for chronic venous leg ulcer due to postphlebitic changes [20,21]. In a retrospective review from the Mayo clinic of 400 Palma procedures, reported patency rates were 70 and 83 percent at three and five years, respectively. Predictors of success were good inflow and no significant infrainguinal venous obstruction or incompetence. These results were confirmed by other studies reporting that the Palma procedure using autologous saphenous vein offered the best long-term patency (78 percent at five years) [20,21].

The main limitations for Palma procedure are the availability of adequate-caliber saphenous vein (preferred lumen is 6 mm throughout) and the long-term risk of external compression of the vein graft. When small bypass conduits (6 mm or less) are used, residual symptoms can occur, and patency rates are lower [25]. Concerns about graft kinking or compression can generally be mitigated by passing the vein within a ePTFE graft [13,17]. Low flow can be augmented by creating an arteriovenous fistula.

Performing an arteriovenous (AV) fistula is advocated by some for all prosthetic femoro-femoral vein bypasses, and selectively in patients with vein (Palma) grafts if the vein is small (<5 mm) or if pressure gradient between the right and left femoral veins is low (<2 mmHg) [21]. However, this adjunctive procedure remains controversial given that outcomes have been inconsistent [13]. The AV fistula is constructed between the graft (saphenous vein, ePTFE) and the ipsilateral superficial femoral artery using one of the side branches or by using a 4 × 7 mm tapered ePTFE graft. The fistula is marked for later identification. For patients in whom an AV fistula was not initially performed who develop graft thrombosis, an AV fistula can be added at the time of graft thrombectomy.

To perform the Palma procedure:

●Donor vein exposure and isolation – An ultrasound-guided groin incision ipsilateral to the obstruction is made and carried down to the CFV. Preservation of all venous collateral is imperative. The CFV and DFV are exposed. The anterior surface of the CFV is dissected. Patency of CFV is confirmed by palpation and Doppler flow (augmented flow). If the CFV is diseased and DFV is patent, endophlebectomy from the CFV to the DFV with patch angioplasty will be required prior to the cross venous anastomosis.

●Recipient vein exposure – An ultrasound-guided groin incision is made contralateral to the obstruction to dissect and mobilized the GSV. This step can be performed simultaneously if two vascular surgeons are available. The saphenofemoral junction (SFJ) is exposed. All tributaries of the GSV at the SFJ are isolated and preserved. The length of GSV needed for the bypass is measured. The GSV is isolated to the knee, ideally using small, interrupted incisions guided by intraoperative ultrasound (linear probe/B-Mode). Tributaries are ligated while harvesting the vein. The transected saphenous vein distally is ligated with silk 0-0. The GSV is distended carefully with heparinized solution to check for leaks, and the anterior surface is marked to prevent twisting during the tunneling.

●Graft tunneling – A suprapubic subcutaneous tunnel is created between the two groin incisions using a tunneler that is left in place. The patient is heparinized (80 U/kg bolus) intravenously. The GSV (attached at the SFJ proximally) is marked on its anterior surface and carefully passed through the tunnel fully distended to avoid any twisting or kinking.

●Anastomosis – The recipient CFV and DFV are controlled individually. A vertical venotomy is made in the CFV using a #11 blade and extended with Potts scissors. An end-to-side anastomosis is constructed between the reversed saphenous vein graft and GSV using 5-0 or 6-0 Prolene suture. Following completion of the anastomosis, the clamps are removed, and duplex ultrasound is used to confirm patency of the saphenous graft and CFV.

●Closure – Hemostasis is achieved. Wounds in the donor thigh are closed in two layers. A closed suction drain is placed in both groin incisions. The vertical groin incisions are closed in layers. Two hours after surgery, intravenous unfractionated heparin is started to obtain an activated partial thromboplastin time between 60 and 70 seconds for a period of at least 72 hours.

Femoroiliac or iliocaval bypass — Femoroiliac or iliocaval bypass are venous reconstructions that provide inline flow between the groin and iliac vein, or iliac vein and vena cava, respectively. Depending on availability of vein, either a spiral vein conduit (12 to 14 mm) or externally ringed ePTFE can be used. Exposures of the various vessels are described above. (See 'Incisions and venous exposure' above.)

●Femoroiliac bypass – Femoroiliac bypass is used for isolated CFV or external iliac vein occlusion for patients in whom a Palma procedure is not an option secondary to the absence of adequate contralateral saphenous vein, or contralateral venous occlusive disease. A vertical groin incision may be extended to suprainguinal groin as a retroperitoneal flank incision or separate groin and retroperitoneal incisions can be used.

●Iliocaval bypass – For isolated common iliac vein obstruction even in presence of proximal external iliac or distal IVC occlusion, an ePTFE bypass from the external iliac vein to IVC is feasible. The IVC can be exposed through a retroperitoneal incision (right-sided iliac vein occlusion) or via a transperitoneal approach (left-sided iliac vein occlusion). The graft is tunneled retroperitoneally, and the distal and proximal anastomoses created.

Bifemoral-caval bypass — For patients with extensive distal vena caval obstruction including bilateral common and external iliac veins, bifemoral-caval bypass is needed. This operation requires midline laparotomy and bilateral groin incisions. Options include a bifurcated ePTFE (eg, 16mm x 8mm x 8 mm graft) or a unilateral femorocaval graft (eg, 16mm x 8 mm) with a cross-femoral ePTFE graft (8 mm) to the contralateral groin.

FACTORS AFFECTING GRAFT PATENCY — Open surgical venous reconstruction is challenging, and long-term patency is affected by the type of conduit, graft material, venous pressure, and any coagulation abnormalities. In a review of 44 venous reconstructions for nonmalignant obstruction, primary and secondary patency rates at a median of 2.5 years follow-up were 77 percent (CI 60 to 100 percent) and 83 percent (CI 67 to 100 percent), respectively, for the femoro-femoral vein bypass (Palma procedure) [20]. For iliocaval and femorocaval bypass grafts, primary and secondary patency were 38 percent (CI 19 to 76 percent) and 54 percent (CI 33 to 89 percent), respectively. The main challenge for open venous reconstruction is graft thrombosis with loss of patency because of low venous pressure, particularly when performed with prosthetic conduit. In addition, the presence of robust anterior abdominal wall venous collaterals from chronic venous occlusion can further reduce flow by a competitive flow phenomenon that may compromise graft patency. Many patients with iliocaval venous obstruction also have coagulopathy that can contribute to postoperative thrombosis, especially for prosthetic grafts. Finally, increased intra-abdominal pressure or technical concerns related to extrinsic compression on these grafts from an overlying artery, organs, or ligaments may further compromise graft patency.

Postoperative anticoagulation — There is no consensus about anticoagulation following venous bypass. The author's opinion is to use oral anticoagulation only for patients with a history of deep vein thrombosis if not contraindicated. Long-term anticoagulation can also be considered following creation of Palma bypass for chronic iliac vein occlusion. Oral anticoagulation can be started on third postoperative day and continued for at least three months.

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Superficial vein thrombosis, deep vein thrombosis, and pulmonary embolism" and "Society guideline links: Chronic venous disorders".)

SUMMARY AND RECOMMENDATIONS

●Potential candidates for venous reconstruction – Despite good outcomes with endovenous intervention, complications (eg, stent migration, collapse, thrombosis) can occur, and for some patients, stenting is not an option. Open surgical reconstruction can be used to manage unsuccessful iliocaval stent placement, recurrent obstruction following iliocaval stenting, vena cava filter thrombosis not amenable to endovenous intervention, or for reconstruction following vein resection for tumor or trauma or hepatic transplantation. (See 'Potential candidates' above.)

●Evaluation – Prior to open surgical venous reconstruction, we obtain bilateral lower extremity venous duplex to verify venous obstruction, but also to evaluate for superficial or deep venous reflux and to map the lower extremity veins. Cross-sectional imaging using CT or MR venography is useful to characterize the iliocaval segment, identify any extrinsic compression, and to identify significant venous collaterals. We also perform catheter-based venography for a detailed assessment of venous anatomy and to verify the severity of obstruction (pressure gradient of ≥5 mmHg). (See 'Preoperative evaluation' above.)

●Options for reconstruction and selection – The technique selected for open reconstruction depends on the length of the venous lesion, diameter of the affected vein, and availability of conduit. Techniques for focal lesions or segmental loss include venous patch angioplasty and vein interposition grafts. For reconstructing segmental loss of larger veins, a spiral vein graft is an option. For longer obstructions or loss, options include venous bypass and in-line venous reconstruction. (See 'Techniques' above and 'Approach to venous reconstruction' above.)

•Unilateral occlusion – For unilateral iliocaval venous obstruction, femoro-femoral, femoroiliac, or femorocaval venous bypass restores outflow using great saphenous vein (GSV) or prosthetic graft material, typically using expanded polytetrafluoroethylene (ePTFE). Vein grafts at risk for kinking may be placed through an ePTFE graft. (See 'Femoro-femoral venous bypass' above and 'Femoroiliac or iliocaval bypass' above.)

•Bilateral occlusion – For bilateral iliocaval venous obstruction, bypass from the femoral vein to the inferior vena cava (IVC) or even superior vena cava is used to restore venous outflow. These reconstructions are usually long, and ePTFE is often selected as the conduit. (See 'Bifemoral-caval bypass' above.)

●Patency and postoperative anticoagulation – There is no consensus regarding anticoagulation following open surgical venous obstruction. The risk of postoperative thrombosis is increased for patients with a history of chronic venous obstruction, particularly following deep vein thrombosis (ie, postthrombotic syndrome [PTS]). For patients with PTS, we initiate postoperative anticoagulation starting on the third postoperative day and continue it for at least three months. It may be reasonable to initiate anticoagulation for other factors that reduce graft patency (eg, hypercoagulability) or others identified at the time of the operation (eg, low flow, long segment graft reconstruction), or to extend the duration of anticoagulation. (See 'Factors affecting graft patency' above and 'Postoperative anticoagulation' above.)