Nozomu Tanji md phd, Department of Urology, Ehime University School of Medicine, Shitsukawa, Tohon-city, Ehime 791-0295, Japan. Email: firstname.lastname@example.org
Aim: The application of cardiopulmonary bypass to atrial involvement represents an important advance that has improved the safety and technical efficacy of a difficult surgical undertaking. Our experiences of the management of extended thrombi into the right atrium in patients with retroperitoneal malignancy using a cardiopulmonary bypass were discussed.
Methods: Data were reviewed for five patients (two men and three women; mean age, 60.4 years; range, 49–79 years) with retroperitoneal tumors displaying intracardiac tumor extension. Tumors originated in the right kidney in four patients, and in left adrenal gland in one patient. Cardiopulmonary bypass was used in all cases.
Results: Mean total blood loss was 6059 mL. Mean operative time was 14.7 h. No intra- or postoperative complications due to surgical technique were encountered, and no significant bleeding occurred during incision of the inferior vena cava or after removal of tumor thrombus. The follow-up period ranged from 3 to 20 months with a mean of 12.6 months. Of the five patients, three died of metastatic diseases, one died of liver dysfunction and one remains disease free as of 18 months postoperatively.
Conclusions: Our experience indicates that this procedure can be safely used for atrial involvement. Although superior long-term survival cannot be shown yet, favorable early results and a lack of perioperative complications were identified.
Retroperitoneal malignancies, such as renal cell carcinoma (RCC) and adrenocortical carcinoma, can extend into the inferior vena cava (IVC). Tumors may extend as far as the right atrium in a small number of the cases.1 Spread of the tumor may lead to infarction of the lungs or other organs. Moreover, tricuspid atresia, caused by extension into the right ventricle through the right atrium, may be fatal.
As caval invasion in the case of adrenocortical carcinoma is quite rare, prognosis in such cases remains unclear. The review of 29 cases by Hedican and Marshall shows a 5-year survival rate of <10%.2 In patients displaying non-metastatic RCC with involvement of the IVC, 5-year survival rates range between 18% and 68% after complete surgical resection.3,4 Whereas some studies have suggested that the risk of metastases and early death is increased in patients with more cephalad extension of IVC thrombi,5,6 Bissada et al.7 reported that 38% of patients with intracardiac tumor extension and no metastases were alive with no evidence of disease after appropriate surgical resection. Poor results of non-operative treatments have prompted us to attempt radical operations, as complete removal of the tumor thrombus probably provides the only chance of cure.
Radical operations for tumor extension into the right atrium require careful planning.3 Traditionally, a thoracoabdominal approach with median sternotomy to provide adequate exposure and vascular control, and cardiopulmonary bypass has been used. Application of cardiopulmonary bypass to atrial involvement represents an important advance that has improved the safety and technical efficacy of a difficult surgical undertaking.
We describe herein our experiences with the management of extended thrombi into the right atrium in five patients with retroperitoneal malignancies, using a transthoracoabdominal approach with cardiopulmonary bypass.
Data were reviewed for five patients (two men, three women; mean age, 60.4 years; range, 49–79 years) who presented with retroperitoneal tumors displaying intracardiac tumor extension (Table 1). Tumors originated in the right kidney in four patients, and in the left adrenal gland in one patient. Level of vena caval involvement was preoperatively determined using imaging studies including ultrasonography of the IVC, echocardiography and magnetic resonance imaging. Accurate assessment of the cephalad extent of thrombus inside the right atrium using these imaging studies confirmed almost complete occlusion of the IVC lumen, but provided no evidence of vessel-wall invasion by tumor thrombus. In all patients, detailed preoperative studies were performed to evaluate cardiac, renal and respiratory status.
For all patients with renal tumors, the renal artery was embolized using a steel coil 1 day before the operation. The surgical approach involved a thoracoabdominal incision in all cases. First, the heart was exposed by cardiothoracic surgeons. Next, the retroperitoneal vessels were exposed and the renal arteries secured. Regional lymphadenectomy was not performed in any cases. The kidney was isolated outside the envelop of Gerota's fascia. Liver and IVC mobilization techniques were important to achieve successful thrombus removal. Intraoperative ultrasonography of the hepatic veins was valuable in patients with suspected intrahepatic tumor extension. If the tumor extended into the hepatic vein, partial hepatectomy was considered. The ascending aorta, right atrium and superior vena cava were then cannulated after systemic heparinization. Subsequent cannulation of the right femoral vein was performed through a small inguinal incision to obtain additional venous drainage. Cardiopulmonary bypass was performed next, without circulatory arrest or cooling of the patient (Fig. 1). The bypass circuit (SIII; Stockert, Munich, Germany) was associated with vacuum-assisted venous drainage with a released valve, providing a negative pressure of 20–40 mmHg in the venous line. Vascular control was achieved by clamping the infrarenal and intrapericardial IVC and the contralateral renal vessels. The hepatic artery and portal vein were clamped as well to reduce bleeding from the hepatic veins. The renal artery was ligated in the proximal position of the coil after gentle retraction of the ipsilateral renal vein. Tumor thrombus was extracted by simultaneous atrial and caval approaches, and removed along with the kidney. The IVC was irrigated, inspected and cleared of residual neoplastic tissues before closure. If removal of more than half of the IVC wall was needed, a polytetrafluoroethylene patch-graft was anastomosed to the remaining IVC with a running 4–0 polypropylene cardiovascular suture. Finally, sequential removal of the vascular clump, arrest of cardiopulmonary bypass, decannulation, vascular suture, administration of protamine sulfate and hemostasis were accomplished.
Of the five patients, four presented with symptoms such as general fatigue, macrohematuria, or dyspnea on effort, and two displayed signs including foot edema related to vena caval obstruction. All patients underwent complete extraction of thrombus from the IVC. Consequently, the plane between the thrombus and the intima was easily identified and the thrombus could be gently freed from the IVC wall and extracted whole. Mean total cardiopulmonary bypass time was 72 min (range, 50–130 min) and weaning from bypass was uneventful (Table 2). No significant bleeding was noted during incision of the IVC or after removal of the tumor thrombus. Mean total estimated blood loss was 6059 mL (range, 1550–12 200 mL). Mean volume of transfusion was 29.2 U (range, 20–40 U). Mean operative time was 14.7 h (range 9–22 h). No intra- or postoperative complications due to surgical technique were encountered. Postoperative respiratory function remained normal.
Pathological examination revealed clear cell carcinoma in the four renal tumors, and adrenocortical carcinoma in the adrenal tumor. Symptoms and signs that were apparent preoperatively all resolved. Mean follow up was 12.6 months (range, 3–20 months). Of the five patients, three died of metastatic diseases, one died of liver dysfunction and one remains disease free as of 18 months after surgery.
The surgical approach to retroperitoneal tumor extending into the right atrium is challenging. Non-metastatic tumors are potentially curable provided complete removal of cancerous tissue can be achieved. The presence of intracaval tumor extension does not affect any independent prognostic value in cases of RCC,8 whereas previous investigations have suggested that cephalad extent of tumor thrombus exerts a substantial impact on clinical prognosis.5 In addition, dissection of tumor thrombus extending into the right atrium reportedly results in significant therapy-related mortality.5 However, the lower frequency of peri- and postoperative complications and improved long-term survival following extracorporeal circulation have been reported.8,9 Some reports advocate the use of cardiopulmonary bypass to facilitate removal of tumor thrombus, particularly tumor thrombus extending into the right atrium.10,11 Important goals are to minimize bleeding and prevent pulmonary embolism of the thrombus, which can have disastrous and often fatal consequences. Cardiopulmonary bypass can be safely used, allowing atrial and IVC thrombectomy to be performed in a bloodless and clearly visible operative field within a safe time interval. Resection can easily include parts of the vessel wall if infiltration is present. Some authors have advocated profound hypothermia and circulatory arrest in patients.10,11 However, we achieved satisfactory visualization and excision using cardiopulmonary bypass without hypothermia or circulatory arrest, avoiding potential renal, hepatic, neurological or septic complications associated with circulatory arrest.
Use of liver and IVC mobilization techniques helps to achieve additional exposure and enables the surgeon to have excellent control of the IVC, thus minimizing blood loss, and allowing the IVC to be opened both below and above the liver so that tumor thrombus is removed as effectively as possible in a bloodless field.
However some concerns exist with regard to possible dissemination of carcinoma cells by means of extracorporeal circulation. This problem of possible dissemination remains controversial. In addition, disadvantages include a comparatively more invasive procedure due to the need for sternotomy, in addition to the need for cardiopulmonary bypass equipment and the assistance of thoracic surgeons.
In conclusion, our experience indicates that this procedure is relatively safe. Although superior long-term survival cannot be shown yet, favorable early results including improvement of symptoms such as general fatigue or loss of appetite after surgery and a lack of perioperative complications were identified. Further experience is necessary to evaluate whether this method can actually improve prognoses in such cases. Anyway, the surgical challenges inherent in resecting intracardiac extension of retroperitoneal malignancies require close cooperation between the urologist and gastrointestinal or cardiovascular surgeons.