164: Resection of Patients with Superior Vena Cava Syndrome

Thoracic surgeons are routinely involved with patients with superior vena cava obstruction (SVCO) and on occasion are called upon to resect the superior vena cava (SVC) in the course of treatment. This chapter will summarize overall management principles, indications for SVC resection, the proper patient evaluation with coordination of care, intraoperative considerations, and postoperative care principles to ensure a successful outcome.

General thoracic surgeons serve the patient with SVCO in three ways. First and most commonly they are involved in the workup and diagnosis of the patient who presents with the spectrum of SVCO symptoms and a chest mass on radiographic studies. Second, a patient with severe symptoms from SVCO will need expedient management of life-threatening symptoms. Similar to approaching the patient with esophageal cancer a “Captain of the Ship” is needed in both above situations which often will require the coordination of care of a multidisciplinary team (oncology, radiation oncology, interventional radiology, pathology) and nonoperative means of treatment will often be utilized (radiation, chemotherapy, stenting, thrombolytic therapy). Last, the thoracic surgeon may be called upon to resect the SVC for benign or malignant disease.

When called upon to evaluate the patient with SVCO the thoracic surgeon should classify the patient by severity of the SVCO symptoms, achieve an expedient tissue diagnosis, coordinate the care of the multidisciplinary team of physicians, and evaluate if there is any role for therapeutic surgical intervention especially if the patient has a diagnosis of non–small-cell lung cancer (NSCLC), thyroid/thymic cancer, or germ cell neoplasm.

Approximately 35% of SVCO patients will be asymptomatic or have only mild symptoms of head and neck edema and cyanosis. Moderate-to-severe symptoms will be seen in 60% of patients manifested by increasing degrees of cerebral edema resulting in visual disturbances, headache, laryngeal edema, and diminished cardiac reserve. Patients will present with life-threatening symptoms 5% of the time.¹

See proposed grading system for superior vena cava syndrome (Table 164-1).

As proposed by Detterbeck, patients with grade 4 symptoms require a venogram, urgent stenting, and possible thrombolytics. Patients with grade 1, 2, and 3 symptoms require tissue diagnosis and multidisciplinary discussion to decide on treatment modality based on particular tumor response to a specific modality. Surgery is usually considered for NSCLC, thymoma, thymic carcinoma, or a residual germ cell mass. Chemoradiotherapy is the mainstay of treatment for patients with small-cell lung cancer, lymphoma, or germ cell tumor. Supportive care only may be indicated for patients with treatment refractory tumors or poor performance status.

See treatment algorithm of superior vena cava syndrome (Table 164-2).

Indications: Malignancy is the most common (90%) cause of SVCO usually due to bronchogenic carcinoma (>50% cases) with mediastinal lymphomas or germ cell neoplasms accounting for the rest.² Occasionally, patients with SVCO of a benign etiology (sarcoidosis, histoplasmosis, fibrosing mediastinitis, iatrogenic thrombosis) may benefit from venous reconstruction to establish flow from the superior venous system to the right atrium.^3,4

When approaching the patient with a malignant tumor involving the SVC, complete resection of all diseases should be the goal. Overall, patients should have acceptable ECOG performance status of 0 to 1 because of the potential moderate morbidity associated with surgery. For patients with a diagnosis of lung cancer, acceptable pulmonary functions on the higher end of normal are required because of the extent of resections and possible need for sacrifice of the phrenic nerve.⁵ Right-sided lung cancers with SVC involvement require a lobectomy at the minimum, and sleeve resection or pneumonectomy is often required.

Preoperative Evaluation and Imaging

Goals are to obtain a tissue diagnosis, establish the proper stage of disease, facilitate planning of the vascular reconstruction if needed, and predict the ability to achieve a complete (R0) resection.

Core-needle biopsy (CT or US guided), mediastinoscopy,^6,7 mediastinotomy bronchoscopy, EBUS, EUS, and VATS biopsies can all be utilized to confirm the diagnosis and lymph node or other sites of potential metastatic involvement. Fusion PET-CT can focus on areas of potential metastatic sites.

The surgeon must have complete understanding of the venous anatomy involved, in particular the site and extension of venous obstruction, the presence of proximal thrombosis, the degree of venous collateralization (complete or incomplete), and the site where the proximal graft anastomosis can be made. Besides initial workup with plain chest roentography a chest CT scan with contrast, magnetic resonance venography,⁸ or superior vena cavography (simultaneous injections through both upper limbs)² can delineate the exact location of venous obstruction, collateralization present, presence of proximal thrombosis, confirm patency of the jugular and axillary veins if needed, and identify sites of proximal graft anastomosis.

ECHO is often useful to assess biventricular function, confirm that there is no thrombosis with extension into the right atrium, and assess for any degree of tricuspid regurgitation. Brain CT or MRI should be done to rule out metastatic disease or any intracranial pathology that may increase brain edema during SVC cross clamping.

When there is no metastatic disease on preoperative staging, an R0 resection is thought possible, and the patient has an acceptable performance status, the patient should be offered resection. A carefully thought-out operation planned in advance will go a long way to insure success and minimize SVC clamp times if needed.

A double-lumen endotracheal tube is useful in obtaining better exposure of the operative field through one-lung ventilation. A Foley catheter is placed to monitor urine output. Electrocardiographic monitoring is standard and especially helpful if inadvertent clamping of the SA node is done. Radial arterial line monitoring is needed to track and manipulate mean arterial pressures to maintain adequate central perfusion. A venous pressure line in the forearm, antecubital fossa, or right internal jugular can monitor the pressure in the cephalic territory and help in assessing the arterial-venous brain parenchymal gradient. In addition to the usual upper extremity vascular access, large bore lower extremity access should also be available if caval clamping is required. Temporary inflow occlusion tolerance will be facilitated by intravascular fluid expansion. Vasoactive agents can also be used once volume status is optimized.

See intraoperative checklist (Table 164-3).

Surgical approach to the tumor is based on location of the mass in question, involvement of associated structures besides the SVC, and degree of vascular exposure needed. Bronchogenic tumors usually require a right thoracotomy through the fifth intercostal space, which allows access to the right hilum, SVC, and RA. Control of the left brachiocephalic vein can be difficult through this approach unless an extended hemiclamshell incision is added. Patients with an anterior mediastinal mass will be approached through a median sternotomy as this provides access to both brachiocephalic veins, innominate vein, SVC, right atrium, and entire anterior mediastinum. The incision also can be extended into the neck if needed.

Clamping of the SVC can result in an increase of cranial venous pressure by 40 mm Hg.⁹ To maintain cerebral perfusion reverse Trendelenburg positioning, volume expansion, vasoconstrictive agents, and hyperventilation to reduce vasogenic cerebral edema should be utilized. Intravenous heparin sodium (50–100 units/kg) should be given 5 to 10 minutes before any vascular occlusion. The cava should be clamped proximal to the azygos vein if possible to preserve collateral circulation and to reduce cerebral edema. The surgeon must avoid clamping the cavo-atrial junction to avoid injury to the SA node.

Once operative exposure is obtained with visualization of the tumor and appropriate isolation of vascular structures, the surgeon can evaluate his preoperative assessment and confirm the extent of resection based on involvement of the SVC by tumor. Tumors that involve less than 30% of the SVC can be handled with a tangential resection and primary repair through use of a side-biting vascular clamp. Reconstruction can be done with 4-0 prolene running suture. Closure of up to 50% of the cava can be done without hemodynamic consequence.

Tumors with 30% to 50% involvement of the SVC may best be served by resection of the SVC and patch repair Figure 164-1. Bovine pericardium or autologous pericardium has been used with success.^10–13

Tumors with greater than 50% involvement of circumference of the SVC will require complete resection and reconstruction (Figure 164-2A–E). PTFE-ringed Gore-Tex (W.L. Gore and Associates, Flagstaff, Arizona) is the most commonly used material for reconstruction today, mainly because of its ease of use and ability to avoid compression. Cryopreserved arterial allograft, spiral saphenous vein, and pericardial tubes have all been reported as possible conduits.^9,10,14,15

Dartevelle proposes that SVC revascularization can be classified into four options: truncal, solitary to the left brachiocephalic vein, solitary to the right brachiocephalic vein, or rarely to both brachiocephalic veins. The proximal conduit anastomosis in SVC revascularization should be performed to the side that is technically easiest and has the most viable blood flow with ligation of the contralateral side in almost all cases. Endovascular staplers facilitate division of the cava and major venous branches.

Truncal: Truncal replacement requires a tumor-free zone on both brachiocephalic veins. Once proximal (brachiocephalic vein confluence) and distal (cavo-atrial) control is obtained, the involved segment is removed. A straight (not ringed) PTFE graft (#14 –20) is used for reconstruction. Sizing of the conduit is variable and can be done visually at the time of resection. A 5-0 prolene is used to perform the proximal (SVC to graft) anastomosis, and then the distal (graft to atrial) anastomosis. Before tightening down the distal anastomotic sutures the proximal clamp is released, the graft is flushed with heparinized saline, and deaeration is done.

Left brachiocephalic vein: A ringed PTFE graft (#12 –14) is used to prevent kinking. Minimal dissection should be done on the left brachiocephalic vein trunk to prevent rotation. This usually requires a long portion of graft that should be tailored in a gentle curve to prevent kinking after the sternotomy is closed. Sequence of anastomosis and deairing is as previous. The distal anastomosis can be done to the distal caval stump, atrial appendage (clear any muscle chords), or atrium proper.

Right brachiocephalic veins: Once again a ringed PTFE graft (#12 or #14) is used. The direction of the graft is vertical, so kinking risks are minimal. The proximal anastomosis can be difficult because the resulting right brachiocephalic stump can be very short.

Both brachiocephalic veins: This is the rarest of reconstruction situations. It is technically more demanding and because of the competing blood flows it has the highest chance of graft thrombosis. It is reserved for the patient who has already had resection of either the right or left internal jugular vein from thyroid cancer surgery. Y-grafts should be avoided because of the increased thrombogenicity of Gore-Tex to Gor-Tex surfaces. The right limb should be anastomosed to the SVC stump and the left limb to the right atrium.

See summary of SVC reconstruction options (Table 164-4) and diagram (Fig. 164-1).

The surgeon must be prepared along with his team for dealing with hemodynamic compromise when clamping the SVC and its major tributaries. The steps in dealing with this would be well discussed during the surgical “time out” as a safety briefing at the beginning of the case. The degree of obstruction of the SVC predicts the potential deleterious cascade of events that can ensue if clamping of the SVC is required. Patients with complete SVCO may have little hemodynamic compromise once the SVC is clamped because of the extensive collateral circulation that will maintain blood flow back to the heart. In this situation the “clamp and go” technique will usually suffice. With adequate intravascular volume and pressor agents inflow occlusion for over 30 minutes should be well tolerated without hemodynamic compromise or sequelae of cerebral edema. Conversely, clamping the SVC in patients with partial SVCO may result in decreased cardiac inflow and outflow, increased venous pressure in the cephalic territory, and changes in the cerebral arterial-venous gradient leading to brain ischemia and intracranial bleeding. When SVC clamping results in unstable hemodynamics, clamp times over 60 minutes are anticipated, or the SVC needs to be clamped below the azygos vein shunting (external vascular shunting or internal vascular shunting) should be considered.⁵ Warren et al., have advocated either an external or internal shunt for such occurrences.¹⁰ An external vascular shunt can be inserted through proximal and distal SVC 4-0 prolene purse-string sutures (Fig. 164-3). A partial or complete resection of the SVC can be accomplished without interrupting venous return to the heart using these techniques. An internal shunt can be placed through a right atrial 4-0 prolene purse-string suture (Fig. 164-4). The shunt is maneuvered to the level of the innominate veins. Venous tapes can be secured to establish SVC isolation while shunting the venous return into the right atrium. It is critical that the shunt be maintained at the proper depth and orientation to maintain venous return to the heart. Drawbacks of shunting are their potential for thrombosis and the cluttering of the operative field making the distal anastomosis difficult. The use of cardiopulmonary bypass has been described in the literature but appears to be rarely needed. Indications may be when an extremely prolonged clamp time is anticipated, massive bleeding is encountered during the course of resection, extended resection of cardiac structures are planned, or unanticipated need for SVC resection discovered at the time of operation. This last instance is a situation that should be avoided at all costs as “being prepared” is an absolute for these cases.

To complete an R0 resection often times other structures besides the cava are involved necessitating resection. If a mediastinal tumor involves both sides of the chest, the surgeon should work from left to right to gain exposure for caval resection and reconstruction. The remaining right-sided portion of the tumor resection can then be completed. For right-sided bronchogenic tumors (especially those involving the carina or main PA) caval resection and reconstruction is usually done first followed by the pulmonary resection. Care must be taken to avoid bacterial seeding of any graft material during pulmonary resection.

Standard drains should be placed to promote lung expansion and a dry postoperative field with one caveat; any drains should not be in contact with the graft material to avoid seeding of bacteria on the conduit. A combination of a chest tube and Blake or Jackson-Pratt drain can be efficacious in this situation.

Anticoagulation started in the OR usually is not actively reversed with protamine. Heparin sodium is maintained in the postoperative period at 1 to 2 mg/kg. Once the chest drains are removed, the patient can be converted to oral agents (Coumadin). The more collateral venous circulation that has developed may induce a higher likelihood of graft thrombosis because of competitive flow. If graft thrombosis is suspected ultrasound or venography should be carried out to confirm and delineate any graft kinking or other technical error that would require a reoperation. More likely is a spontaneous thrombosis that can be treated by interventional radiology through catheter techniques, thrombolytics, and further anticoagulation.

The patient should be maintained in a 30 to 45 degree upright position. If a unilateral reconstruction was done to only one of the brachiocephalic veins, the contralateral arm should be elevated above the heart on pillows or a padded bedside table to decrease limb swelling.

Manipulation of the sinus node can result in postoperative sick sinus syndrome. Placement of a temporary or permanent pacemaker may be indicated.

Standard early ambulation and encouragement of pulmonary hygiene should be done as in any thoracic procedure along with DVT prophylaxis.

Review of the literature of resection for patients with SVCO of a malignant etiology shows a 5-year survival of 31% against a 9% operative mortality. The presence of metastatic N2 nodes has less favorable outcomes. Patients with malignant mediastinal tumors that cause SVCO historically do better than those with bronchogenic carcinoma that involves the cava.^11,16 See summary of results of SVC resection (Table 164-5).

Patients with SVCO can be best treated with a multidisciplinary approach to their evaluation led by a thoracic surgeon. Surgery with resection of tumor, SVC, and reconstruction is often indicated for malignant etiologies (NSCLC, thymoma, residual germ cell tumor). Optimal results are achieved in patients who can undergo an R0 resection of all known diseases. Superior vena caval resection and reconstruction techniques can help achieve this goal.

A 41-year-old male presented to the thoracic surgical services with grade 1 symptoms of SVCO (head and neck edema, mild cyanosis, plethora). An 8- × 14-cm mass was demonstrated on CT scan of the chest (Fig. 164-5). Core-needle biopsy was interpreted as a thymic carcinoid tumor. Because of concern with resectability and the acute nature of the SVCO he received cisplatinum-based chemotherapy for three cycles and mediastinal radiation to 4800 cGy.

The patient was then restaged after treatment with fusion PET/CT. No metastatic disease was found and surgical resection was planned. The patient had a median sternotomy done with isolation of the right and left brachiocephalic veins, innominate veins, and significant venous tributaries. The pericardium was widely opened exposing the SVC-RA junction. After dissection of the mass a caval resection would be required as planned preoperatively. A clamp and go technique was utilized without need for pressors after adequate volume expansion. After clamping the SVC and right and left brachiocephalic veins, the venous structures were divided with endovascular staplers. Brisk bleeding was found and controlled with oversewing after localizing to the azygos system which was adherent in the tumor mass. The right atrium was opened and cleared of chordae tendineae and a 14-mm ringed Gore-Tex graft was fashioned with a bevel and anastomosed with 4-0 prolene to the right atrial appendage. After checking this anastomosis for hemostasis the graft was fashioned in a gentle curve back to the left brachiocephalic vein and another 4-0 prolene anastomosis was completed, the graft deaired, and the clamps released (Fig. 164-6). No reversal agents were given. Heparin was maintained in the postoperative period and held prior to chest tube removal. The patient was converted to oral anticoagulation in the postoperative period after the chest tubes were removed on postoperative day 2. He was discharged home and had no evidence of disease until 14 months later when he presented with a symptomatic pericardial effusion and lung metastasis. He succumbed to metastatic disease in spite of salvage chemotherapy 18 months after resection.

The evolution of superior vena caval reconstruction techniques provides a valuable example of why thoracic surgeons need to constantly reevaluate our assumptions about locally advanced cancer. Evolving surgical techniques may offer options for patients whose disease was previously considered “inoperable.” Importantly, this reassessment must be made in the context of the individual patient's disease process and physiologic reserve.