A bi-institutional retrospective review was performed for patients undergoing right radical nephrectomy and en bloc resection of IVC and TT between 2006 and 2021. Only patients with obstructing thrombus levels II-IV were included. Cranial extent of tumor was defined per our own classification for level III11, and the classification by Neves and Zincke was used for level II and IV thrombus.12 Level III thrombi were classified as level IIIa (retrohepatic), level IIIb (hepatic), level IIIc (suprahepatic, infradiaphragmatic), or level IIId (supradiaphragmatic, infra-atrial) (Figure 1).11
After extensive evaluation and cardiology clearance, informed consent was obtained for right radical nephrectomy and thrombectomy with or without IVC reconstruction with possible cardiopulmonary bypass (CPB). CPB was planned in advance for cases of level IV thrombus with a large intra-atrial component, although the cardiothoracic team was on standby for all cases. Data collected included patient demographics; tumor characteristics including size, TT level, pathology, grade, and stage; intra-operative factors such as estimated blood loss (EBL), blood transfusions, use of CPB; complications; length of stay; and survival. Pre-operative creatinine was recorded, as was creatinine on day of discharge, and at 6 and 12 month follow-up. When creatinine result was not available for the exact follow-up time point (6 or 12 months), the value at the time closest to the intended time was used, so long as it was in a 3 month window (thus for 6 month follow-up, 3-9 month creatinine could be included, and 9-15 month creatinine for 12 month follow-up). All procedures described in this report were in accordance with the ethical standards of the University of Miami Miller School of Medicine and Hospital General Universitario Gregorio Marañón Institutional Review Boards and the Helsinki Declaration (as revised in 2013)
Following the technique previously described by Ciancio et al.,1− 3,11,13 a modified Chevron or J-shaped Makuuchi incision were used to gain abdominal access. A liver surgery self-retaining retractor (Rochard or Omni-Tract®) was used in every case to create enough space at the level of diaphragmatic domes to further facilitate the approach to the suprahepatic segment of the IVC.
The right renal artery was identified, ligated and divided by creating a posterior plane of dissection or at the level of inter-aortocaval sulcus.13 After its division, the collateral venous circulation collapsed, making the remaining dissection easier to perform. The liver was completely mobilized off of the IVC, with the only remaining structural attachments being the major hepatic veins (Piggyback liver mobilization) and the liver hilum.1–3, 13 A plane was then created between the IVC and posterior abdominal wall to obtain circumferential control of the IVC. At this level, the engorged small tributaries (often confused for lumbar vessels) needed to be properly identified and ligated to prevent significant bleeding and to facilitate stapling of the IVC.
If TT extended to or above the diaphragm, the central tendon of the diaphragm was dissected to the supra-diaphragmatic area, until the intra-pericardial IVC was fully exposed (Figure 2). The dissection was circumferential so that the intra-pericardial IVC could be completely encircled below or above the confluence into the right atrium (RA). The RA was gently pulled beneath the diaphragm and into the abdomen. If more exposure of the RA was required, the central tendon of the diaphragm could be incised at the midline, allowing the pericardium to be exposed, and a pericardiotomy could be performed. Use of intra-operative transesophageal echocardiography (TEE) was critical to delineate the cranial extent and mobility of the tumor thrombus during dissection of the retrohepatic IVC, supra-diaphragmatic IVC and RA, and to confirm that there were no pulmonary artery emboli or TT extending into the RA. In addition, the intra-operative TEE acted as a guide during application of the vascular clamp onto the RA (if needed for proximal control due to extent of TT), making sure that the clamp excluded tumor and that the coronary sinus was not obstructed.
In cases of level IV thrombi with large intra-atrial component not fully accessible from the abdominal field, the use of CPB was considered necessary and planned in advance. For this purpose, a midline sternum incision was used. Cannulation was performed in a standard fashion through the right atrium, right femoral vein, and distal ascending aorta (Figure 3). Proximal aortic clamping and additional cannulation was used for plegic solution administration when required. The type and parameters of CPB utilized was discretional upon the criteria of the cardiothoracic team involved and do not represent a constant along the study period since a historical series is reported. Overall, CPB shifted from deep hypothermic under cardiac arrest to normothermic beating heart during the study period.
Once the liver and IVC were completely mobilized via the Piggyback technique, vascular clamps were placed in the infra-renal IVC, followed by the left renal vein. The TT was then milked below the major hepatic veins, and the IVC was clamped without the need of Pringle maneuver. If the TT was bulky, not freely mobile, and could not be milked downward out of the intra-pericardial IVC, Pringle maneuver was performed to temporarily occlude blood inflow to the liver. For level IV thrombi requiring bypass, thrombus was removed through a RA incision performed after CBP was initiated. Once the bulky atrial component was removed, the remaining proximal thrombus was pushed downwards and removed through the cavotomy, ensuring complete thrombus removal and full patency of the major hepatic veins ostia. The cavotomy was sutured closed in its proximal segment and the IVC was stapled just below the major hepatic veins, and distal to the tumor thrombus caudal end (Figure 4). The left renal vein was either stapled or oversewed. At the end of the resection, TEE was repeated to rule out any pulmonary artery emboli or piece of TT left behind.