Vena Caval Involvement by Renal Cell Carcinoma Surgical ... - NCBI

Vena Caval

Involvement by

Renal Cell Carcinoma

Surgical Resection Provides Meaningful Long-Term Survival

DONALD G. SKINNER, M.D., T. RAND PRITCHETT, M.D., GARY LIESKOVSKY, M.D., STUART D. BOYD, M.D., and QUENTIN R. STILES, M.D. In 1972 we first reported that vena caval extension by tumor thrombus was a potentially curable lesion provided that complete removal could be achieved. We have developed a technique for safe removal of extensive vena caval thrombi extending up to the right atrium without the need for cardiopulmonary bypass or hypothermic cardioplegia. Cardiopulmonary bypass, however, is advocated for some type III thrombi, but the addition of the pump and heparinization compounds the magnitude of the procedure. We use a right thoracoabdominal approach for tumors arising from either kidney with vascular isolation of the vena cava from its insertion into the right atrium to the iliac bifurcation. From 1972 to 1988, 56 patients ranging in age from 31 to 76 years were evaluated and 53 underwent radical nephrectomy with en bloc vena caval tumor thrombectomy. Of these patients, 21 had subhepatic caval thrombus extension (level 1); 24 had extension into the intrahepatic vena cava (level 2), and 8 had thrombi extending into the heart (level 3). Overall 1-, 3-, and 5year survival was 56%, 34%, and 25%, respectively. Crucial to survival was complete surgical excision. Successful extirpation of all apparent tumor was possible in 75% of the patients in this series. With an expected 5-year survival rate of 57% for those without metastatic disease to other organs, we continue to advocate an aggressive optimistic approach for patients if there is no preoperative evidence of metastatic disease.

ENAL CELL CARCINOMA has a natural tendency to expand into the areas of least resistance as well as to directly invade contiguous structures or metastasize via the regional lymph nodes or hematogenously. Direct extension of renal cell carcinoma into the vena cava has been found in 4% to 10% of patients undergoing nephrectomy to treat cancer.",2 In 1972 it was recognized that venous extension by tumor thrombus was a potentially curable lesion provided that complete reR5

Presented at the 109th Annual Meeting of the American Surgical Association, Colorado Springs, Colorado, April 10-12, 1989. Correspondence and reprint requests to: Donald G. Skinner, M.D., Professor and Chairman, USC Medical Center, Department of Urology, 2025 Zonal Avenue, GH 5900, Los Angeles, CA 90033. Accepted for publication: April 14, 1989.

From the University of Southern California Medical Center, Department of Urology, Department of Surgery, Division of Cardiothoracic Surgery, Los Angeles, California

moval could be achieved.3 Between 1972 and 1983 we treated 25 patients with vena caval tumor thrombus secondary to renal cell carcinoma. We used a technique for safe removal of extensive vena caval thrombi extending up to the right atrium without the need for cardiopulmonary bypass or hypothermic cardioplegia. We reported our clinical review and surgical technique for these 25 patients in 1986.4 Since treating those 25 patients, we have evaluated 32 more patients with renal cell carcinoma with extension into the vena cava. In this report we (1) present the clinical review of the 53 patients we have treated by radical nephrectomy and vena caval tumor thrombectomy for renal cell carcinoma; (2) update our follow-up on the original 25 patients; and (3) discuss changes in our management technique based on improvements in technologies and lessons learned from our more recent experience.

Materials and Methods From 1972 to 1988, 64 patients with vena caval tumor thrombus were evaluated. Thrombi in seven patients were secondary to Wilms' tumor, adrenal cortical carcinoma, transitional cell carcinoma, or leiomyosarcoma, while in 57 patients the thrombi were secondary to renal cell carcinoma. Of these patients, 56 were considered operative candidates and underwent surgical exploration. The charts were reviewed retrospectively. Preoperative Evaluation Patient age ranged from 31 to 76 years, with an average age of 59 years. There were 35 men and 21 women. He-

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performed as part ofthe preoperative evaluation. The patients were divided into three groups according to the level of the vena caval tumor thrombus: level 1-21 patients with tumor thrombus extension below the insertion of the hepatic veins; level 2-24 patients with tumor thrombus extension within the intrahepatic vena cava but not into atrium; and level 3-8 patients with intra-atrial tumor thrombus extension (Fig. 1). As with our previous report, this anatomic grouping of patients based on the cephalad extent of the thrombus determined the operative approach.4 Forty-three patients had no evidence of metastatic disease before operation and 13 patients had metastatic disease diagnosed before operation by CT. Results

Patient positioning for resection of renal cell carcinoma with caval extension. Note that the patient's right side is adjacent to the ipsilateral edge of the operating table. A seventh or eighth rib-excising incision is used to provide adequate cardiac exposure. (Reproduced by permission from: Skinner D, Lieskovsky G, eds., Diagnosis and Management of Genitourinary Cancer. Philadelphia: W.B. Saunders, 1988. p. 697). FIG. 1.

vena

maturia was present in 37% of patients. Symptoms or signs of vena caval obstruction were present in 41% of patients. A varicocele was noted in 34% ofthe men. Fiftythree patients underwent radical nephrectomy with complete removal of the vena caval tumor thrombus. The tumors were on the right side in 34 patients and on the left side in 19 patients. All patients since 1982 had preoperative computed tomograms (CT) of the abdomen. All patients underwent an inferior vena cavagram or magnetic resonance imaging (MRI) to evaluate the vena cava. Superior vena cavography or echocardiography was performed if there was inferior vena caval occlusion or if the uppermost extent of the venous tumor thrombus was unclear on MRI.5 Arteriograms were not routinely

Ofthe patients, 56 had surgical exploration and 53 underwent radical nephrectomy with en bloc vena caval tumor .thrombectomy. Three patients with known metastatic disease and debilitating symptoms secondary to vena caval obstruction were found to be inoperable. The surgical approach used was the same as we have reported before.4 The patient is placed in the modified right thoracoabdominal position, regardless of from which side the tumor arises (Fig. 1). The surgical maneuver necessary for vena caval isolation and thrombus removal are depicted in Figure 2. Three ofthe eight patients with intra-atrial involvement required cardiopulmonary bypass to facilitate tumor extraction from the atrium. Of the 43 patients with no known preoperative metastases, 17 were found, during operation, to have metastatic disease, but complete resection of all tumor was possible in 40 patients. Of those 17 patients found to have metastatic tumor intraoperatively, 8 (47%) had lung involvement, 5 (29%) had involvement of contiguous viscera, 2 (12%) had liver metastases, and 2 (12%) had mediastinal involvement. Thirteen of these 17 patients had CT preoperative scans that failed to show the liver or contiguous visceral involvement. Using our surgical technique, a Pringle maneuver is necessary for level 2 and level 3 tumors and contralateral renal ischemia is necessary for all three levels. Our average liver and renal warm ischemia time was 14 minutes and ranged from 8 to 20 minutes. Vena caval ligation or clipping with a nonocclusive clip to prevent thromboembolism was performed in 17 patients (32%). Intraoperative complications included three deaths: two due to exsanguination, and one due to a massive tumor pulmonary embolus. The average blood loss was 5466 cc, with an average replacement of ten units (range, 1 to 70 units). The mean blood loss for left-sided tumors was 6620 cc and for right-sided tumors it was 4800 cc (Table 1).

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The mean blood loss for level 3 was 10,063 cc, compared cc for levels 1 and 2, respectively (Table 1). For the 22 patients with evidence of vena caval obstruction, the mean blood loss was 6664 cc, compared to 4587 cc for those without evidence of vena caval obstruction. Of the eight level 3 patients, three required cardiopulmonary bypass to extract the atrial tumor thrombus. Two of these patients underwent successful tumor extraction with blood losses of 7500 and 9000 cc. The third patient died from intraoperative exsanguination. There were four other perioperative deaths due to sepsis and multiple organ system failure, yielding an operative mortality rate of 13% (7 of 53 patients). The other patients had a median postoperative hospital stay of 12 days (range, 5 to 58 days). Postoperative complications occurred in 41% of patients and included hepatic dysfunction 11%, renal failure requiring temporary dialysis (8%), sepsis (8%), pancreatitis (2%), arrhythmia (2%), prolonged ileus (2%), adrenal insufficiency (2%), and pleural effusion (2%). to 4575 cc and 4675

Pathologic Findings Of the 53 patients who underwent radical nephrectomy and tumor thrombectomy, histologic examination revealed 28 patients with clear cell type, 21 with clear cell and granular cell, and 4 with spindle cell type renal cell carcinoma.

Pathologic staging of these 53 patients showed that 9 had no evidence of spread outside the kidney, 9 had invasion into fat alone, 8 had spread into nodes, and 27 patients had metastatic disease. Survival

The 53 patients with vena caval tumor extension have been followed for 6 to 116 months, with a median followup of 62 months. Our original 25 patients4 (who are included in this series) have all been followed for more than 5 years. Table 2 shows the actuarial Kaplan-Meier 5-year survival rates for all 53 patients and the actual 5-year survival rates for the first 25 patients in this series.6 Of the 53 patients, 46 (87%) lived to be discharged from the hospital, and 40 (75%) had complete excision of all grossly recognized tumor. Several factors show an impact on survival: the level of the vena caval tumor extension, the extent of local tissue involvement, whether a complete excision of all tumor was possible, and the presence ofmetastatic disease. The 5-year actuarial survival rates for level 1, 2, and 3 tumors were 35%, 18%, and 0%, respectively. These correspond closely to the 5-year actual survival rates of 42%, 20%, and 0%. While one of our level 3 patients is alive with metastatic disease at 50 months, we have had no 5-

FIG. 2. Surgical maneuvers necessary for a safe and effective method of removing all tumor thrombus. For tumors with levels 2 and 3 extension, a vertical pericardiotomy is performed; the phrenic nerve is avoided and a Rumel tourniquet is applied loosely around the intrathoracic inferior vena cava at this level. The superior mesenteric artery is isolated and occluded with a soft Fogarty vascular clamp. The inferior mesenteric artery is similarly occluded. Two Crafoord vascular clamps are placed on the porta hepatis, after which the Rumel tourniquets on the distal vena cava, the contralateral renal vein, and finally the intrathoracic cava are tightened, isolating the vena cava from all venous inflow except for pooled blood within the hepatic system. For left-sided tumors, a soft Fogarty vascular clamp is placed on the right renal artery, thus obviating the need to occlude the right renal vein. (Reproduced by permission from: Skinner D, Lieskovsky G, eds., Diagnosis and Management of Genitourinary Cancer. Philadelphia: W.B. Saunders, 1988. p. 699).

year survivors to date. In the absence of metastatic disease to other organs, the presence of perinephric fat or nodal involvement is comparable to the intrarenal neoplasm with vena caval extension. The 5-year actuarial survival TABLE 1. Mean Estimated Blood Loss (cc) by Tumor Side and Level Side

Right Left

Total

Level 1

Level 2

Level 3

Total

4800 (34) 6621 (19) 5466 (53)

2773

3966

(12)*

(17)

6777

4575

6400 (7) 4675

12,100 (5) 6600 (3) 10,063

(21)

(24)

(8)

(9)

* ( ) are number of patients in each group.

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SKINNER AND OTHERS TABLE 2. Five-Year Survival Rate (%)

All Patients Level 1 Level 2 Level 3 - fat, - nodes + fat + nodes Stage III Stage IV Complete resection

Right Left + IVC obstruction - IVC obstruction

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idence of inferior vena caval obstruction had similar 5year survival rates of 28% and 29%, respectively.

Number of Patients

Actuarial*

Actual

53 21 24 8 9 9 8 26 27 40 34 19 22 31

29 35 18 0 40 47 60 47 0 34 23 44 28 29

28 42 20 0 38 50 33 41 0 33 26 33 33 23

(25)t (12) (10) (3) (8) (6) (3) (17) (8) (21) (19) (6) (12) (13)

* By method of Kaplan and Meier.6 t ( ), number of patients followed for 5 years.

rates for those patients with negative perirenal fat and nodes, positive perirenal fat, and positive nodes were 40%, 47%, and 60%, respectively. These are similar to the actual 5-year survival rates of 38%, 50%, and 33%. When all three of these "local" stages are grouped together, these patients had a 5-year actuarial and actual survival rate of 47% and 41%, respectively. Of the 40 patients in whom complete excision of all grossly recognized tumor was accomplished, the 5-year actuarial and actual survival rates were 34% and 33%, respectively. However if a complete resection of all grossly apparent tumor was impossible, only 8% were alive at 1 year, with the longest survivor living only 19 months. For those patients without metastatic disease recognized before operation, the 5-year actuarial and actual survival rates were 32% and 33%, respectively. For those 13 patients with metastatic disease diagnosed before operation, three were unresectable and ten underwent radical nephrectomy with resection of the vena caval tumor thrombus, but only five had a complete resection of all grossly apparent tumor. Of these ten patients, the median survival was 4 months and the longest survivor lived 13 months. More than one half of our 53 patients (27) had metastatic disease apparent at time of surgery. None of these patients lived 5 years, but the actuarial and actual 1-year survival rates were 37% and 26%, respectively. Of these 27 patients with metastatic disease, 13 underwent complete resection of all apparent tumor and had a mean survival of 9 months (the longest survival was 21 months). Whether the tumor was right sided or left sided did not predict survival. While the difficulty of surgically excising a left-sided tumor was increased, the 5-year actual survival rates for left- and right-sided tumors were 33% and 26%, respectively (Table 2). Those patients with or without ev-

Discussion Our experience with the management of these 53 patients who underwent radical nephrectomy with complete removal of the vena caval tumor thrombus represents the largest series reported to date. Since our review of the 25 patients we treated from 1972 to 1983, numerous reports of the successful management of this disease have been published.7'4 While most investigators now have an optimistic outlook, the magnitude and risks of this type of surgery remain high. The presenting signs and symptoms of our patients have not changed greatly over the past 16 years. Evidence of vena caval obstruction is apparent in about 40% of patients, with 30% to 40% of men having a varicocele on physical examination. Those patients with vena caval obstruction frequently have multiple large collateral veins in the abdominal wall, Gerota's fascia, the diaphragm, and in the colonic mesentery as new paths of venous blood return to the heart develop to bypass the caval obstruction. We still advocate preoperative anticoagulation of these patients with subcutaneous heparin until six hours before surgery to prevent sudden preoperative disseminated intravascular coagulopathy (DIC). At surgery it is not unexpected that these patients with extensive venous collaterals would have a higher mean blood loss (6664 cc versus 4587 cc). However an increased mortality rate was not seen in this group and in the 5-year actuarial survival ratio of those patients with vena caval obstruction versus those without was similar (28% versus 29%). To prevent pulmonary emboli, we used anticoagulation after operation, and DeWeese nonocclusive vena caval clips were placed across the infrarenal vena cava in those patients who had clots below the level of their tumor thrombus. Our preoperative evaluation still requires exact delineation of the cephalad extent of the tumor thrombus. While this can still be defined best by vena cavography, we now use MRI because it is noninvasive. The major advantages of MRI are that thrombosis versus patency in the vena cava can be determined without the use of an intravenous contrast agent and that MRI can acquire images of the vena caval tumor thrombosis in sagittal, coronal, and axial planes.5 Because MRI images are less exact in the beating heart, we use echocardiography, as well as superior vena cavography with cardiac angiography, if atrial involvement is expected. However with the further refinement of MRI and cardiac gating, the majority of these patients will no longer require these invasive venous catheterizations to determine the cephalad extent of the thrombus.

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While CT scanning and abdominal ultrasound can often accurately determine the extent of the thrombus, we do not rely on these studies alone. Although CT scanning is sometimes inadequate, we use it to stage all our patients. Of our patients, 13 had metastatic disease diagnosed before operation by the CT scan. The presence of known metastatic disease before operation prevents successful curative surgery. However surgery should be done in the patient if a single focus of metastatic disease can be completely excised or if it is intended to provide palliation. Those patients who have debilitating symptoms from vena caval thrombus can be provided with an improved quality of life for several months by excising the tumor. Because the median survival of those patients undergoing surgery with known metastatic disease before operation was only 4 months, the surgery should be considered only if the symptoms of vena caval obstruction are severely debilitating or if death is imminent without surgical intervention. Most patients with evident preoperative metastatic disease should not undergo an attempt at surgical resec-

tion. While our surgical approach has not changed for patients without extensive atrial involvement, our anesthetic technique has evolved over the past several years. We now advocate the use of vasodilation, IV hydration with a mixture of 5% albumen and lactated Ringer's solution in a ratio of 1:2, and hypotensive anesthesia. This anesthetic technique has been described.'5 The intraoperative monitoring of end tidal carbon dioxide level is routinely used by our anesthesiologist to detect the event of a pulmonary embolus quickly. While the salvage of a patient with an intraoperative embolus has been reported, we have not been so fortunate.'6 Our one patient with a clinically recognized intraoperative pulmonary embolus could not be resuscitated. The management of those patients with cardiac extension of the tumor thrombosis must be individualized. Numerous different methods of management have been reported. 7"10"1417-20 Although we did not advocate the use of cardiopulmonary bypass for these patients in our earlier report, we have found it necessary in three of eight patients with intra-atrial involvement. The increased risk of hemorrhage secondary to the required heparinization should not be underestimated. Due to this risk, we continue to avoid cardiopulmonary bypass in those patients with minimal atrial involvement. In these patients the atrial thrombus can be pushed back into the intrathoracic inferior vena cava via a small atriotomy through the atrial appendage so that the thrombus can be extracted in the same way as a level 2 thrombus (Fig. 2). The decision to perform cardiopulmonary bypass is made at the time that the intracardiac portion of tumor is explored with a finger inside the atrium (Fig. 3). If the tumor can be easily pushed

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./.? IG. 3. The cardiac surgeon can insert a finger through the atrial appendage and into the right atrium to ease the tumor thrombus out of the atrium at the time that the primary renal tumor and thrombus are simultaneously extracted from the abdominal vena cava. Once the thrombus has descended out of the atrium into the proximal inferior vena cava, a Rumel tourniquet is tightened around the inferior vena cava at its junction with the atrium. This maneuver provides proximal venous control, prevents intraoperative embolization, and obviates the need for cardiopulmonary bypass. (Reproduced by permission from: Skinner D, Lieskovsky G, eds. Diagnosis and Management of Genitourinary Cancer. Philadelphia: W.B. Saunders, 1988, p. 700).

back into the vena cava, a tourniquet around the vena cava and adjacent to the heart can be tightened to prevent embolization during extraction from below. If the tumor is bulbous in its intracardiac portion, requiring extensive manipulation to push it below the diaphragm, it is probably safer to use cardiopulmonary bypass to prevent embolization. The average blood loss of 5466 cc for our 53 patients is higher than the average of 3600 cc reported in our original 25 patients.4 The value is higher because we have treated patients with more extensive caval involvement. Four patients with extensive venous collaterals had estimated blood loss of more than 10,000 cc. Two of these patients died in the postoperative period. The average blood loss is higher with the higher level of vena caval involvement and is higher for left-sided tumors than rightsided ones (Table 1). This is probably due to the increased development of collateral veins. Also obstruction of the hepatic veins may depress hepatic function, producing a relative coagulopathy. In comparing the survival rates of our original 25 patients undergoing surgery between 1972 and 1983, the

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actual 5-year survival rates are very similar to those predicted by the method of Kaplan and Meier.6 For all 25 patients, both the predicted and actual 5-year survival rates were 28%. For those patients undergoing complete resection of all grossly recognized tumor, the predicted and actual 5-year survival rates were 36% and 33%, respectively.4 Thrombus level appears to be an important prognostic variable. Our level 1 patients had a 5-year survival rate of 35%, compared to only 18% for level 2 patients. None of the level 3 patients have lived 5 years. The extent of local disease does not appear to be an important prognostic variable as long as contiguous viscera are not involved. The patients with perinephric fat or nodal involvement had similar 5-year survival rates to those without (40% to 60%). However no patients with other organs involved survived 5 years. Of the 53 patients, 27 were found to have metastatic disease at the time of surgery, but 14 of these 27 had all grossly evident metastatic disease resected. Of the 43 patients without evidence of metastatic disease before operation, 17 were found to have metastatic disease at surgery. However complete resection of all grossly evident tumor was possible in 35 of the 43 patients without preoperatively diagnosed metastatic disease, and in five of 13 patients known to have metastatic disease before operation. Successful extirpation of all apparent tumor was possible in 75% of the patients in the series. With an expected 5-year survival rate of 34% for these patients and a survival rate of 47% for those patients without metastatic disease to other organs, we continue to advocate an aggressive, optimistic approach for these patients if there is no preoperative evidence of metastatic disease. References

4. 5.

6. 7.

8. 9. 10. 11.

12.

13. 14. 15.

16. 17.

18. 19.

1. Skinner DG, Vermillion CD, Colvin RB. The surgical management

of renal cell carcinoma. J Urol 1972; 107:705. 2. Keamey GP, Waters WB, Klein LA, et al. Results of inferior vena caval resection for renal cell carcinoma. J Urol 1981; 125:769. 3. Skinner DG, Pfister RF, Colvin R. Extension of renal cell carcinoma

DISCUSSION

DR. HAROLD C. URSCHEL (Dallas, Texas): I would like to commend Dr. Skinner for his pioneering work in this field, for his encouragement and assistance to us when we began our work here in the early 1970s and for an excellent presentation. My comments relate to nine patients we have treated with extension into the heart (Dr. Skinner's type 3): seven were renal cell, one was leiomyosarcoma, and one was adrenal cell carcinoma. We agree with and employ Dr. Skinner's general principles but we have evolved a slightly different technical approach. We use a midline sternotomy with a midline laparotomy because we believe it is quicker,

20.

Ann. Surg. September 1989

into the vena cava: the rationale for aggressive surgical management. J Urol 1972; 107:711. Pritchett TR, Lieskovsky G, Skinner DG. Extension of renal cell carcinoma into the vena cava: clinical review and surgical approach. J Urol 1986; 135:460. Pritchett TR, Raval JK, Benson RC, et al. Preoperative magnetic resonance imaging of vena caval tumor thrombus: experience with 5 cases. J Urol 1987; 138:1220. Kaplan EL, Meier P. Nonparametric estimation from incomplete observations. J Am Statis Assoc 1958; 53:457. Vaislic CD, Puel P, Grondin P, et al. Cancer of the kidney invading the vena cava and heart: results after 11 years of treatment. J Thorac Cardiovasc Surg 1986; 91:604. Giuliani L, Giberti C, Martocana G, Rovida S. Surgical management of renal cell carcinoma with vena cava thrombus. Eur Urol 1986; 12:1451. Emmott RC, Hayne R, Katz IL, et al. Prognosis of renal cell carcinoma with vena caval and renal vein involvement. Am J Surg 1987; 154:49. Hedderich GS, O'Connor RJ, Reid EC, Mulder DS. Caval tumor thrombus complicating renal cell carcinoma: a surgical challenge. Surgery 1987; 102:615. O'Donohoe MK, Flanagan F, Fitzpatrick JM, Smith JM. Surgical approach to inferior vena caval extension of renal carcinoma. Br J Urol 1987; 60:492. Neves RJ, Zincke H. Surgical treatment of renal cancer with vena cava extension. Br J Urol 1987; 59:390. Selli C, Barbanti G, Barbagli G, et al. Caval extension of renal cell carcinoma: results of surgical treatment. Urology 1987; 30:448. Libertino JA, Zinman L, Watkins E, Jr. Long-term results of resections of renal cell cancer with extension into inferior vena cava. J Urol 1987; 137:21. Viljoen JF, Thangathurai D. Anesthetic management in radical surgery for urologic malignancies. In Skinner DG, Lieskovsky G, eds. Diagnosis and Management of Genitourinary Cancer. Philadelphia: W.B. Saunders, 1988. pp. 595-600. Markham NI, Doyle PT. Prolonged survival following emergency pulmonary tumor embolectomy and subsequent nephrectomy. Br J Urol 1987; 59:484. Wilkinson CJ, Kimovec MA, Uejima T. Cardiopulmonary bypass in patients with malignant renal neoplasms. Br J Anaesth 1986; 58:461. Marshall FF, Reitz BA. Supradiaphragmatic renal cell carcinoma tumor thrombus: indications for vena caval reconstruction with pericardium. J Urol 1985; 133:266. Klein FA, Smith MJV, Greenfield LJ. Extracorporeal circulation for renal cell carcinoma with supradiaphragmatic vena caval tumor thrombi. J Urol 1984; 131:880. Sosa RE, Muecke EC, Vaugn ED, Jr, McCarron JP, Jr. Renal cell carcinoma extending into the inferior vena cava: the prognostic significance of the level of vena caval involvement. J Urol 1984; 132:1097.

associated with less pain, and allows concomitant bilateral resection of metastatic pulmonary nodules, which was necessary in three of our cases. For this particular subgroup we employ a double lumen endotracheal tube to facilitate collapse of the operated side alternately, just as we recommend for primary pulmonary resection with elective unilateral disease. The median sternotomy allows easy access to cardiopulmonary bypass, which we have chosen to use. We never push the tumor back from the chest with a finger. I don't think we see those cases that Dr. Skinner described, but with that technique we are worried about pulmonary emboli that would be inadvertent, or the dumb bell situation in which you couldn't possibly have done that anyway (three of our seven cases). We withhold the heparin until we have performed the ab-