Intracaval Tumors

WILLIAM C. FAUST

JOHN A. LIBERTINO

A unique feature of renal cell carcinoma (RCC) is its predilection to involve venous structures. Tumor extension can grow intraluminally along the renal vein and propagate into the inferior vena cava (IVC) up to and including the right atrium and occurs in 4% to 10% of cases. Although this does worsen the prognosis, if tumor spread has not occurred to the lymph nodes or otherwise metastasized, these tumors can be controlled surgically using a variety of approaches.

STAGING

In 2010, the American Joint Committee on Cancer published updated guidelines on RCC staging. In those guidelines, as pertains to intracaval tumors, pathologic T3a lesions are those that involve the renal vein or its segmental branches or invades renal sinus or perirenal fat. Pathologic T3b lesions are those that involve the IVC with the most proximal extent below the diaphragm, and T3c lesions are those that extend above the diaphragm. These classifications were modified according to research that showed that proximal extent of tumor thrombus had significant effect on cancer-specific survival (1) and has since been confirmed in larger multi-institutional studies (2).

Various other surgical staging systems have been proposed to define the extent of tumor thrombus and aid in surgical planning including the Neves system, the Novick system, and the Hinman system. At our institution, the Neves system is found to be a rationally organized and commonly used. It is broken down by level of cephalad extent of tumor (Fig. 4.1).

DIAGNOSIS

Preoperative imaging is critically important to plan the surgical approach and determine the need for cardiopulmonary bypass prior to resection. A variety of modalities exist to accurately diagnose the extent of tumor thrombus. Three-dimensional multiplanar computerized tomography can provide not only information about the extent and level of tumor thrombus but also the presence of collateralizations, lumbar venous anatomy, renal arterial anatomy, local surgical staging, and anatomic factors. Magnetic resonance venography is another useful technique routinely used to evaluate venous thrombus involvement (Fig. 4.2A-C). Transthoracic and transabdominal ultrasound can also be useful in patients who cannot undergo abdominal imaging. Finally, for patients undergoing renal artery angioembolization prior to resection, traditional inferior venacavography can be performed simultaneously. This, however, has limited benefit for evaluating the cephalad extent in cases of complete occlusion of the IVC.

PREOPERATIVE ANGIOEMBOLIZATION

Renal artery embolization has evolved over the years from initially a palliative procedure to a preoperative adjunct to resection of locally advanced renal tumors. Preoperative renal angioinfarction facilitates dissection of the renal tumor as a result of local tissue edema from hypoxia and tissue necrosis. It also limits the amount of manipulation on the renal vein prior to resection because the vein may be transected prior to controlling or occluding the renal artery. It has been postulated that preoperative angioinfarction may decrease the extent of tumor thrombus while minimizing venous collateralization (3). It is the practice of the senior author to routinely perform preoperative angioembolization prior to surgical resection for RCC with venous thrombus involvement.

SURGICAL APPROACH

Surgical approaches to intracaval tumor thrombi are subject to extent of IVC involvement, body habitus, prior surgical history, and surgeon comfort. The goal of any surgical approach should be to maximize exposure of the great vessels and involved renal tumor. Tumors that involve the renal vein only typically can be managed with a thoracoabdominal incision in a fashion similar to organ-confined tumors. For right-sided infrahepatic tumors, a thoracoabdominal approach can still be used and provides adequate exposure of the infrahepatic IVC. Left-sided infrahepatic, all retrohepatic, and all supra-diaphragmatic IVC tumor thrombi are approached using an upper abdominal chevron incision with the addition of either a median sternotomy or more recently a mini-access right fourth rib parasternal incision to access the right atrium and supra-diaphragmatic IVC.

After induction of general anesthesia and intubation intraoperative monitoring is performed by placing a right internal jugular central venous MAC two-lumen catheter. Through this, a Swan-Ganz pulmonary artery catheter is introduced and floated into the pulmonary artery. Two large-bore peripheral intravenous lines are placed and if peripheral access is poor, a second 9Fr central venous catheter is placed in the contralateral great vessels. A Belmont Rapid Infuser is available in cases of large volume blood loss, and two Cell Saver devices are used to recycle blood products.

Prior to incision, transesophageal echocardiography is performed to evaluate for tumor thrombus propagation that would necessitate cardiopulmonary bypass. Accurate intraoperative hemodynamic monitoring is critical during the procedure, especially when using cardiopulmonary bypass.
Another useful device for intraoperative monitoring is the real-time electrical impedimetric monitoring of blood coagulation factors, which allows for continuous resuscitation of blood loss and coagulopathy by anesthesia.

FIGURE 4.1 Classification of venous tumor thrombus extension—level I renal vein, level II infrahepatic IVC, level III retrohepatic IVC, and level IV supradiaphragmatic IVC. (Adapted with permission from Wang GJ, Carpenter JP, Fairman RM, et al. Single-center experience of caval thrombectomy with renal cell tumor extension into the inferior vena cava. Vasc Endovascular Surg 2008;42(4):335-340. Copyright © 2008, SAGE Publications.)

For tumor thrombus at or above 2 cm below the hepatic vein confluence, cardiopulmonary bypass and deep hypothermic cardiac arrest are routinely used to ensure a bloodless field in resecting these tumors. Although this approach is associated with risks of systemic anticoagulation and central nervous system impairments, it is the opinion of the senior author that these risks are justified to provide adequate access of the cephalad portion of tumor thrombus to prevent embolization or inadvertent disruption of the caval-atrial junction in milking techniques.

Infrahepatic Inferior Vena Cava Thrombus

The patient is positioned in the supine position with arms extended at 90 degrees. After induction of general anesthesia and placement of anesthetic intraoperative monitoring device, a Foley catheter is placed and the abdomen from the xiphoid to pubis is clipped free of hair and prepped with 2% chlorhexidine ChloraPrep solution from the lower rib cage to the pubis.

For right-sided tumors, a thoracoabdominal approach is used. For left-sided tumors, a chevron incision is made from the tip of the 11th rib to the tip of the contralateral 11th rib. For both right- and left-sided tumors, the initial portion of the procedure is controlling the IVC with limited manipulation to
prevent possible dissemination of tumor thrombus. The peritoneum is entered, and the ascending colon and hepatic flexure are mobilized medially along the line of Toldt. The duodenum is kocherized exposing the right renal vein and IVC. A Bookwalter retractor is the used to provide maximal exposure. A series of short body wall retractors are placed at the 9 o’clock, 6 o’clock, and 4 o’clock position of the wound to retract oblique musculature, subcutaneous tissue, and skin. The duodenum and colon are retracted medially by using a malleable retractor with a moistened laparotomy pad. The liver is retracted cephalad either using a Harrington retractor or malleable retractor with laparotomy pads. Care must be taken to avoid damage to the porta hepatis.

FIGURE 4.2 A: Contrast-enhanced upper abdominal computerized tomography with thrombus seen in renal vein. B: Preoperative cavogram demonstrating filling defect at the T10 level consistent with tumor thrombus in a patient with a large right renal mass. C: Coronal and sagittal magnetic resonance imaging scan demonstrates tumor extending to the level of the diaphragm (left) and further into the right atrium (right).

The IVC is then exposed. The cephalad extent of tumor thrombus is palpated with care to prevent embolization from overzealous palpation. The right gonadal vein is identified and ligated between silk ties to prevent troublesome back bleeding during cavotomy and thrombectomy. For tumor at the junction of the renal vein and IVC or with a small caval extension, a DeBakey clamp is applied to the IVC, the thrombus removed, and the IVC is reconstructed (Fig. 4.3A-D). With larger caval extension, circumferential dissection of the IVC as well as the right and left renal vein is carried out so as to provide for placement of Rummel tourniquets. Lumbar veins as well as minor hepatic veins are identified and ligated to prevent back bleeding. Many times, renal angioembolization will produce an inflammatory response that precludes the need for arterial mobilization, and ligation of the renal artery is deferred until after IVC thrombectomy is performed. Complete occlusion of the renal artery is confirmed, however, by visually inspecting the renal vein as well as palpating the renal artery for persistent flow. If any doubt exists regarding the completeness of arterial occlusion, then renal artery dissection must take place prior to cavotomy to prevent unnecessary bleeding.

Once adequately exposed, Rummel tourniquets are placed on the cephalad extent of the IVC, the contralateral renal vein, and caudal portion of the IVC (Fig. 4.4A-C). They are the occluded in rapid succession in the order of cephalad, vein, and caudal. An anterior longitudinal cavotomy is performed using curved scalpel followed by Potts scissors. This incision follows a curvilinear tract to incorporate the ipsilateral renal ostium, which will be removed en bloc with the complete specimen. The thrombus is then freed from the caval wall using Penfield neurosurgical spatulas. Any areas of caval wall invasion must be resected. If <50% of caval wall is involved, this may then be closed primarily. In cases where >50% of the wall is involved, then reconstruction using either synthetic polytetrafluoroethylene vascular patch or with a variety of bioprosthetic or autologous materials (pericardium, saphenous vein graft, bovine pericardium). The IVC is gently flushed with

heparinized saline and evaluated for any residual fragments. The cavotomy is closed with continuous 4-0 polypropylene sutures. The inferiormost Rummel tourniquet is released first to flush the cava of blood and limit the risk of air embolus.

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