Management of acute intra-operative thromboembolism in renal cell carcinoma.

Renal cell carcinoma (RCC) is the most common malignant tumor of the kidney and has got association with inferior vena cava (IVC) extension in 5-10% of the patients. In this case report, we present a case of a 22-year- young female who was posted for radical nephrectomy and tumor thrombectomy to remove the thrombus extending up to IVC- right atrium junction. The surgical procedure was complicated by intraoperative thromboembolism during tumour manipulation. Continual Trans esophageal monitoring helps in early diagnosis of thromembolic event. Immediate diagnosis and awareness of clinical management in such circumstances contribute to a decrease in the associated morbidity and mortality.

INTRODUCTION

Intra-operative thromboembolism always remains a fearful complication in a patient with renal cell carcinoma (RCC) with thrombus. Tumor disruption and pulmonary embolization are a rare but known complication seen in up to 5.4% of resections of RCC with inferior vena cava (IVC) involvement.[1] Our case report highlights prompt diagnosis and resuscitative measures to be taken during embolism of IVC thrombus and the role of intra-operative transesophageal echocardiography (TEE). After taking written and informed consent from the patient, we wish to report this experience.

CASE REPORT

A 22-year-old female with body mass index 20.2 kg/m2 presented with chief complaints of right flank pain and hematuria for 8 weeks. Her general and systemic examination was unremarkable. The patient had RCC in the lower mid pole of the right kidney with invasion into right renal vein, IVC and extended up to cavo-atrial junction. Transthoracic echocardiography revealed normal biventricular contractility and a thrombus in the right pulmonary artery (RPA).

The surgical procedure involved radical right nephrectomy, followed by IVC thrombus and RPA embolectomy under cardiopulmonary bypass (CPB). General anesthesia was planned. Monitoring including oxygen saturation, electrocardiogram, invasive blood pressure, end-tidal carbon dioxide (EtCO2), temperature, central venous pressure (CVP), and TEE were applied. An 11 Fr. sheath was also introduced in the right internal jugular vein along with CVP catheter. Initial TEE examination showed a thrombotic mass extending from the right renal vein up to the IVC-right atrium (RA) junction [Figure 1] and an isolated organized thrombus in the RPA. Cardiac chambers were free from any thrombus [Figure 2]. A mid-line thoracoabdominal incision was given and during the ligation of renal vein there was a sudden fall in blood pressure, rise in CVP, increase in airway pressure, and a fall in EtCO2. TEE examination showed sudden appearance of thrombus in the RA, extending across the tricuspid valve (TV) into the right ventricle (RV) during the diastolic phase, and almost completely obstructing the flow across the TV. The patient was immediately put in a head down position and fraction of inspired oxygen was increased to 100%. Intravenous fluids and intermittent boluses of injection phenylephrine (50 mcg) was administered to support hemodynamics. Meanwhile, emergency CPB was instituted after systemic heparinization and achieving activated clotting time of >480 s. The patient was cooled to a temperature of 18°C. Fogarty catheter, introduced via a longitudinal incision near the main pulmonary artery bifurcation, into the left pulmonary artery and the fresh thrombus was removed. The RPA was opened near the superior vena cava and both fresh and organized thrombus was retrieved. Thrombus from RA was removed directly. The IVC was almost clear of thrombus except in one portion of intrahepatic IVC, revealed by intra-operative TEE [Figure 3]. The remnant IVC thrombus was approached from the RA end and was extracted by removing it from below the hepatic IVC. Thrombus was removed during intermittent low flow state of 10 min duration. Weaning from CPB was initiated after gradual re-warming. Intra-operative TEE confirmed that there was no residual thrombus. After weaning from CPB, TEE showed mild tricuspid regurgitation with severe pulmonary artery hypertension (with peak RV systolic pressure of 68 mmHg). Injection milrinone was added to the on-going infusion of injection nitroglycerine, injection adrenaline, and injection dobutamine. Patient was shifted to Intensive Care Unit. Trachea was extubated the next morning and patient was shifted toward after weaning from vasoactive infusions on postoperative day 2.

Figure 1

Transoesophageal echocardiography probe in the distal esophagus and turned to right bringing the inferior cavo-atrium junction into view. The image shows the extension of tumor thrombus up to the cavo-atrial junction

Figure 2

A mid esophageal right ventricular inflow-outflow view showing the right atrium and right ventricle devoid of any tumor thrombus

Figure 3

A transgastric view showing remnant thrombus in the intrahepatic portion of inferior vena cava

DISCUSSION

The venous system is involved in around 5–10% cases of RCC.[2] Our case is unique in a way that presurgery pulmonary artery embolism has rarely been reported with RCC.[3] Majority of published case reports are of intra-operative pulmonary artery embolization during resection of the primary tumor[45] which unfortunately happened in our case too. RCC with level I or II thrombus extension can be managed without CPB support as proximal and distal control can be taken to prevent thrombus migration during manipulation. Median sternotomy may be necessitated for thrombus extension level-III or IV or if embolization into PA is present presurgery. Primary median sternotomy was done before hand because the thrombus extension was level-III with right PA embolization and the primed CPB circuit was kept ready.

A high degree of alertness is warranted during the period of renal manipulation and renal vein ligation, and preparedness for the worst-case scenario.[6] The common approach for level-IV thrombus is to go on CPB after nephrectomy.

These patients are prone to excessive bleeding due to raised venous pressure and therefore adequate venous access is important in the event of rapid transfusion. Blood and blood products must be ensured beforehand. Cell saver devices are important can minimize the need for blood transfusions. However, cell saver use is controversial in oncologic surgery with the risk of metastatic spread. E'lias et al.[7] in their study showed no risk of metastatic spread and can be used in cases where excessive bleeding is expected.

In our case, during the renal vein ligation there was hemodynamic instability with sudden fall in the EtCO2 and an increase in airway pressures, all clinically indicating thrombus embolism, which was clearly evident on TEE. TEE also showed us a ball-valve thrombus effect, with the thrombus obstructing TV; so Trendelenburg position was done. Trendelenburg position resulted in migration of the thrombus away from TV, resulting in some improvement in hemodynamics, and given enough time to go on emergency CPB. The importance of intra-operative TEE in such surgeries is clearly supported[1689101112131415] in medical literature and apart from helping in diagnosing thrombus embolization, TEE also helps in performing a comprehensive evaluation of residual thrombus if present after surgery.[1]

This case primarily highlights the prompt diagnosis, preparation, and awareness of resuscitative measures in a case of renal tumors with IVC thromboembolism and the advantage of TEE.