Surgical Reconstruction of the Inferior Vena Cava and Iliofemoral Venous System




Historical Background


The first direct venous reconstruction using a saphenous vein graft for “postphlebitic stasis” was reported in 1954 by Warren and Thayer. In the late 1950s and 1960s venous reconstructions for benign occlusions using a cross-pubic venous bypass were introduced by Palma and Esperon in Uruguay and later popularized in the United States by Dale. Although Perl first described the entity of venous leiomyosarcoma in 1971, descriptions of surgical resection for primary and secondary malignancies of the iliocaval venous system have been largely limited to series reported since 1993.




Indications


Benign Ileofemoral Venous Occlusion


Surgical reconstruction of the inferior vena cava (IVC) and iliac veins for benign disease has been relegated to symptomatic patients with long-segment iliac vein or vena cava occlusions who either are not candidates for stenting or have failed attempts at percutaneous recanalization. The most common cause of benign occlusions is deep venous thrombosis because of May-Thurner syndrome, iatrogenic or blunt trauma, radiation, or external compression from retroperitoneal fibrosis, tumors, or large iliac or abdominal aortic inflammatory aneurysms. Congenital causes of venous obstruction include membranous obstruction of the suprahepatic IVC in either the absence or the presence of hepatic vein occlusion, as in Budd-Chiari syndrome, or hypoplasia of the iliofemoral veins, as observed in Klippel-Trenaunay syndrome.


Malignant IlIofemoral Venous Occlusion


Select patients with primary or secondary malignancies of the iliac veins or IVC may be offered operation ( Box 56-1 ). Candidates include patients without metastatic disease and good cardiopulmonary function who are able to perform daily activities with minimal limitation. Patients with renal cell cancer tumor thrombus extending to the right heart who have limited pulmonary metastases may also benefit from tumor thrombectomy and postoperative chemotherapy.



Box 56-1


Primary





  • Leiomyosarcoma



Secondary





  • Retroperitoneal soft-tissue tumors




    • Liposarcoma



    • Leiomyosarcoma



    • Malignant fibrous histiocytoma




  • Hepatic tumors




    • Cholangiocarcinoma



    • Hepatocellular carcinoma



    • Metastatic (e.g., colorectal)




  • Pancreaticoduodenal cancers



  • Osteosarcoma, osteochondroma, or chordomas involving the lumbar spine or sacrum



Secondary Tumors With Caval Thrombus





  • Renal cell carcinoma



  • Pheochromocytoma



  • Adrenocortical carcinoma



  • Sarcomas of uterine origin




    • Leiomyomatosis



    • Endometrial stromal cell




  • Germ cell tumors




    • Embryonal



    • Teratocarcinoma




TUMORS OF THE INFERIOR VENA CAVA




Preoperative Preparation





  • Duplex ultrasonography and venous plethysmography. Venous duplex ultrasonography, in combination with lower extremity air plethysmography, can be used to determine the site of venous occlusion and assess inflow from the common and deep femoral veins; determine the severity of valve incompetence, which is present in about two thirds of patients; and provide a measure of calf muscle pump function. In addition, exercise testing by conducting 10 ankle dorsiflexions or 20 isometric calf muscle contractions should mimic symptoms and produce a twofold increase in lower extremity ambulatory venous pressure.



  • Three-dimensional computed tomography (CT) or magnetic resonance imaging (MRI). CT and MRI can be used to exclude abdominal or pelvic pathology and with appropriate venous phase imaging to define iliofemoral and vena caval obstruction, as well as collateral veins and the proximity of tumor, if present, to adjacent organs ( Figs. 56-1 and 56-2 ).




    Figure 56-1


    Axial CT images in a caudal to cephalad direction of large vascular renal cell cancer, right liver lobe hepatic metastasis, and intracaval tumor thrombus extending to the hepatic vein–caval confluence. A , A dilated lumbar vein (white arrow) is a consistent finding with suprarenal inferior vena cava (IVC) obstruction and may be a source of significant backbleeding during removal of caval thrombus. A highly vascular renal cell carcinoma is adjacent to the vein. B , The top of the renal cell cancer (white arrow) and beginning of the hepatic metastasis (black arrow) causing compression of the IVC. C , The hepatic metastasis is highly vascular (black arrow), with tumor thrombus within the retrohepatic IVC (white arrow). D , The tumor thrombus extends to the junction of the IVC and right hepatic vein (white arrow).

    (From Bower TC. Venous tumors. In: Cronenwett JL, Johnston KW, editors: Rutherford’s vascular surgery , ed 7. Philadelphia, 2010, Saunders, pp 983-995, Fig. 63-6.)



    Figure 56-2


    Three-dimensional CT venogram confirming occluded left iliac stent with large suprapubic venous collaterals.

    (From Gloviczki P, Oderich GS: Open surgical reconstructions for non-malignant occlusion of the inferior vena cava and iliofemoral veins. In: Gloviczki P, editor: Handbook of venous disorders: Guidelines of the American Venous Forum . London, 2009, Hodder Arnold, pp 514-522.)



  • Transesophageal echocardiography (TEE). TEE may be helpful to determine the proximity of an intracaval tumor thrombus to the hepatic veins or right heart.



  • Ascending and descending venography. Conventional venography via femoral vein access can define venous anatomy, as well as determine whether a stenosis is hemodynamically significant by the presence of a 3 to 5 mm Hg pressure gradient. Normal pressures, however, may be observed at rest because of large collaterals. Intravascular ultrasound is a helpful adjunct in identifying lesions that may otherwise be difficult to identify by conventional, CT, or magnetic resonance venography.



  • Duplex mapping of the saphenous vein. A donor saphenous vein of at least 5 mm in diameter is preferred for a cross-pubic femoral vein bypass (Palma procedure).



  • Cardiopulmonary function. Cardiopulmonary function is assessed with dobutamine stress echocardiography or perfusion studies of the heart.



  • Pulmonary function. Pulmonary function studies and arterial blood gases are performed in those patients with moderate to severe chronic obstructive lung disease.



  • Preoperative embolization of the renal artery. In patients with a large renal cell cancer, renal artery embolization 24 hours before operation may shrink the tumor. Preoperative embolization of internal iliac artery and venous branches may be helpful in patients with large immobile tumors of the sacrum and pelvis to minimize blood loss during resection ( Fig. 56-3 ).




    Figure 56-3


    Axial ( A ) and sagittal ( B ) views of a large pelvic sarcoma partially encasing the left iliac arteries, highlighted with contrast. Venous phase images are not shown, but veins were encased by tumor. The tumor was large and immobile, and endovascular occlusion of distal internal iliac artery and vein branches was performed.

    (From Bower TC: Primary and secondary tumors of the inferior vena cava and iliac veins. In: Gloviczki P, editor: Handbook of venous disorders: Guidelines of the American Venous Forum . London, 2009, Hodder Arnold, pp 574-582.)





Pitfalls and Danger Points





  • Early failure of a cross-femoral venous bypass. A cross-femoral venous bypass may occlude because of small saphenous vein (<4 mm), poor inflow related to obstruction or venous incompetence in the femoral-popliteal and deep femoral systems, inadequate cross-pubic tunnel, kinking at the donor saphenofemoral junction, or lack of an arteriovenous fistula when a prosthetic bypass is used.



  • Selection of cross-femoral bypass conduit. An 8- to 10-mm-diameter expanded polytetrafluoroethylene (ePTFE) bypass should be used when the donor saphenous vein is of small caliber, diseased, or absent.



  • Common femoral vein as an inflow source. If there are thrombophlebitic changes in the common femoral vein, an endovenectomy should be considered.This consists of excising the dense synechiae and endoluminal fibrous tissue with placement of a vein patch ( Fig. 56-4 , A ).




    Figure 56-4


    A , A partially recanalized femoral vein is identified after venotomy. Endovenectomy i performed to remove the organized thrombus and improve inflow into a femoral-femoral crossover venous polytetrafluoroethylene (PTFE) bypass. B , An arteriovenous fistula is placed between the superficial femoral artery and the hood of the cross-femoral PTFE graft. C , A small Silastic sheath is placed around the fistula and marked with metal clips to facilitate identification at reoperation to close the fistula.

    (Courtesy Mayo Foundation for Medical Education and Research.)



  • Cross-femoral pubic tunnel. The suprapubic tunnel should admit two fingers throughout its course.



  • Kinking of a cross-femoral venous bypass. If the saphenous vein kinks at the donor saphenofemoral junction, it should be disconnected from the femoral vein with a 2-mm cuff, rotated 180 degrees, and reanastomosed to the femoral vein.



  • Arteriovenous fistula. The addition of an arteriovenous fistula is important if a prosthetic bypass is used. A 4-mm-diameter branch of saphenous vein or ePTFE graft between the superficial femoral artery and the hood of the donor venous anastomosis is preferred (see Fig. 56-4 , B ). A larger-diameter arteriovenous fistula increases the pressure within the venous system and should be avoided.



  • Internal iliac or lumbar vein bleeding. Ineffectual ligation of short, broad-based internal iliac or lumbar vein branches may lead to hemorrhage. Ligation of only the internal iliac vein trunk in the course of sacral resection or hemipelvectomy increases blood loss when the bone is transected. As many branches of the internal iliac vein as are possible should be ligated and divided to minimize blood loss. To avoid distention of internal iliac vein branches, it is best to initially isolate but not ligate the main trunk or trunks of the internal iliac vein, after which the branches are ligated. Dilated lumbar veins at the renal vein–IVC confluence are a source of significant bleeding when extracting intracaval thrombus ( Fig. 56-1 , C ).



  • Thromboembolism. Malposition of the upper (cephalad) caval clamp during removal of the intracaval tumor thrombus may inadvertently fracture the thrombus and result in pulmonary embolism. Early renal artery ligation to promote tumor thrombus retraction and the use of intraoperative transesophageal echocardiography to be certain that the suprahepatic IVC is free of tumor thrombus may help avoid this problem. Some patients with intracaval tumor thrombus also have occlusive or partially occlusive bland thrombus in the infrarenal cava ( Fig. 56-5 ). If there is concern about maintaining IVC patency, the infrarenal thrombus must be removed in its entirety. Otherwise, a caval filter should be placed.




    Figure 56-5


    A , Schematic of a renal cell carcinoma and tumor thrombus extending from the renal vein into the suprarenal and infrarenal vena cava with associated chronic occlusive bland thrombus. B , Once the tumor thrombus is removed, the IVC is obliquely transected and either oversewn or stapled to avoid a cul-de-sac.

    (Adapted from illustrations created by David Factor, Mayo Foundation. Courtesy Mayo Foundation for Medical Education and Research.)



  • Air embolism. Retrograde and prograde flushing of the iliocaval prosthesis should be performed with the patient in a head-down position and the lungs inflated to a pressure of 30 cm of water to avoid inadvertent air embolism. The graft can also be filled with heparinized saline, and punctures of the graft with a 25-Ga needle can be used to remove air before restoration of blood flow.



  • Iliocaval graft thrombosis and stenosis. Early thrombosis of a large-diameter iliac or caval graft is uncommon. Failure occurs if there is purse stringing of the suture line, causing stenosis, redundancy or compression of the graft, or inadequate inflow. Anastomotic stenosis is avoided by beveling the graft, triangulating the suture lines, and when tying the suture, incorporating at least 2 mm of “growth factor” (air knot).



  • Selection of an iliocaval conduit. Autogenous vein grafts in the abdomen are prone to compression; therefore the use of ePTFE grafts is preferred for iliocaval replacements, with preservation of as many graft rings as feasible, even in the region of the beveled anastomosis.



  • Avoiding graft torsion at the hepatic veins. When the retrohepatic IVC requires replacement, the tendency is to cut the graft too long. This is avoided by measuring the length of the graft needed with the lungs maximally inflated and then deflated before cutting the graft to length. In addition, the graft is cut with the liver or the liver remnant rotated to its normal position to avoid torsion at the hepatic veins. If the upper graft anastomosis is at the level of the hepatic veins, the suprahepatic clamp is best secured in a supradiaphragmatic extrapericardial position so that the vein cuff does not slip through the clamp ( Fig. 56-6 ). Manipulation of stiff grafts can be difficult, so a parachute suture technique may be helpful.


Mar 13, 2019 | Posted by in VASCULAR SURGERY | Comments Off on Surgical Reconstruction of the Inferior Vena Cava and Iliofemoral Venous System
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