Editing Open Kidney Surgery (section)

=== IVC Thrombectomy ===

* '''Usually, IVC thrombectomy is accompanied by radical nephrectomy and regional lymph node dissection'''
*'''<span style="color:#ff0000">Classification of IVC thrombi</span>'''

{| class="wikitable"
|'''Thrombus level'''
|Incidence rate in RCC
|Proportion of thrombi
|'''Cranial extent of thrombus'''
|'''Management of tumour thrombus'''
|-
|'''0'''
|12%
|65%
|'''Confined to renal vein'''
|'''Radical nephrectomy'''
|-
|'''I'''
|2%
|10%
|'''Within 2 cm of renal vein ostium'''
|'''IVC milking, partial IVC occlusion,'''

'''ostial cavotomy'''
|-
|'''II'''
|3%
|15%
|'''Below hepatic veins'''
|'''Complete IVC mobilization/control,'''

'''infrahepatic cavotomy'''
|-
|'''III'''
|1%
|5%
|'''Between hepatic veins and diaphragm'''
|'''Complete occlusion: suprahepatic'''

'''IVC clamping, infrahepatic'''

'''cavotomy'''

'''Partial occlusion: veno-venous'''

'''bypass, infrahepatic cavotomy'''
|-
|'''IV'''
|1%
|5%
|'''Above diaphragm'''
|'''Deep hypothermic arrest, infrahepatic cavotomy, right atriotomy'''
|}

* See [https://www.researchgate.net/figure/Classification-of-tumor-thrombus-level-according-to-the-Mayo-staging-system-Level-0_fig1_257812494 graphic representation] of thrombus level

==== Pre-operative considerations ====
* '''<span style="color:#ff0000">Anticoagulation</span>'''
** Patients with kidney cancer are at increased risk of pulmonary embolism as a result of malignancy-associated hypercoagulability and venous thrombus embolization.
**'''<span style="color:#ff0000">Intravenous or low-molecular-weight heparin should be started as soon as tumor thrombus is detected</span>'''
***Potential benefits (3):
***#Reduce risk of pulmonary embolism
***#Tumour thrombus shrinkage
***#Bland thrombus shrinkage and/or prevention
***Evidence supporting the use of preoperative anticoagulation is limited
***Temporary suprarenal IVC filters are also an option for patients with level 0, I, and II tumor thrombi. However, suprarenal IVC filters are not recommended because of the risk of contralateral renal and hepatic vein thrombosis, the risk of provoking embolization, and the impediment that these devices can pose to future IVC thrombectomy.
*'''<span style="color:#ff0000">Preoperative angioembolization'''
**'''<span style="color:#ff0000">Can be considered to attempt to shrink the thrombus and facilitate surgery''' 
**Indications (4):
**#Caval thrombi appears to invade the IVC
**#Thrombus is associated with a bleeding kidney
**#When deep hypothermic arrest is planned since the patency of the coronary arteries can be simultaneously assessed with angiography
**#Thrombus invades the intrahepatic or suprahepatic veins and cannot be excised
**#*Angiographic infarction of the blood supply to the tumor thrombus can help shrink a large thrombus to a more manageable size, potentially avoiding the need for bypass or extensive mobilization of the liver.
**In ≈1/3 of cases, tumour thrombi have an independent blood supply arising from the renal artery and/or aorta.
**Timing
***Optimal timing for angioembolization is unknown but at most centers, when undertaken, it is usually performed 1 day prior to surgery.
** Complications
*** Iatrogenic pulmonary embolization of the tumor thrombus when angiography is performed; however, this risk appears to be minimal.
*** Ischemia-related flank pain
*** Tumor lysis syndrome
*'''Multidisciplinary Approach'''
**Urologists who do not routinely handle the IVC and aorta should consult a vascular surgeon for level II and III thrombi to aid in vena caval control and reconstruction.
**Consultation with a cardiothoracic surgeon preoperatively for all level III and IV thrombi is essential, since access to the mediastinal compartment for vascular bypass and thrombus removal may be required.
**Involvement of a cardiologist or cardiac anesthesiologist is essential for level II to IV thrombi to allow for intraoperative TEE.
***'''<span style="color:#ff0000">Intraoperative use of transesophageal echocardiography (TEE) for level II to IV thrombi is recommended given the risk of intraoperative thrombus detachment and the possibility of interval thrombus growth in the period immediately preceding surgery.'''

* '''Surgical approach'''
**'''Tailored to the level of IVC thrombus. In general:'''
*** '''Level I thrombi are isolated by a Satinsky clamp''' and are thus readily addressed
*** '''Level II thrombi require sequential clamping''' of the caudal IVC, contralateral renal vasculature, and cephalad IVC along with mobilization of the relevant segment of the IVC and occlusion of lumbar veins. The renal ostium is then opened and the thrombus is removed, all in a bloodless field.
*** '''Level III thrombi may require mobilization of the liver and exposure of the intrahepatic IVC''' to allow the thrombus to be mobilized caudad to the hepatic veins, and venous isolation can then proceed as for a level II thrombus.
*** '''Level IV thrombi have traditionally been managed with cardiopulmonary bypass and hypothermic circulatory arrest'''
**** '''A hypocoagulable state follows when coming off the pump following hypothermic circulatory arrest. This is associated with increased risks of cerebrovascular accident and myocardial infarction'''
**** Hypothermic circulatory arrest is still the preferred approach in complex cases but some centers are now trying to avoid it
*** When tumor thrombus invades the wall of the vena cava, aggressive resection of the involved cava and attainment of negative surgical margins are required to minimize the risk of recurrence. IVC grafting or reconstitution is required in some instances.

==== Level 1 vena caval thrombectomy ====

* '''Can usually be treated in a similar fashion to level 0 thrombi by reducing the thrombus into the renal vein'''
**Usually, level I thrombi are partially occlusive, are nonadherent, and do not require extensive IVC dissection or any form of bypass. 
* '''Surgical plan'''
**Position: anterior midline or anterior subcostal
**'''Step-by-step'''
***Position a self-retaining retractor
***Medialize the colon and develop the anterior pararenal space
***'''Identify and expose the great vessels and the renal hilum'''
***'''Identify and ligate the renal artery''' 
****Renal artery can be ligated in the intera-ortocaval region, if right-sided, or para-aortic if left-sided
****Take care care not to manipulate the renal vein or IVC too much. 
****Secure the renal artery with 0 silk ligature or a large clip. 
****Ligating the renal artery early will help reduce the blood flow to the kidney and minimize the amount of potential blood loss.
***'''Gently mobilize the kidney outside the renal fascia, divide the ureter, and dissect the IVC above the right renal vein.'''
****Some groups mobilize the kidney after the thrombectomy is complete, in order to minimize the risk of embolization, while others mobilize the kidney first followed by thrombectomy
***Identify and secure the contralateral renal vein, suprarenal IVC, and infrarenal IVC with vessel loops.
****To help with temporary ligation of these vessels, 3- to 6-inch portions of an 18-Fr red rubber catheter are passed through the vessel loop and used as Rummel tourniquets.
*****While this degree of vascular control may not be necessary for all level I thrombi, it is prudent to have adequate vascular control if there is any doubt about the extension of the level of thrombus.
****Starting cranially, the IVC is gently pinched closed, and then the Rummel tourniquets are applied so that the infrarenal IVC, contralateral renal vein, and suprarenal IVC are closed in that order. 
***'''Using the left hand, milk the IVC toward the ostium of the renal vein. Place a C-shaped Satinsky vascular clamp around the ostium of the renal vein''' partially occluding the IVC, ensuring that the thrombus is located within the jaws of the clamp before complete closure. 
****Palpate the IVC for evidence of any other thrombus.  
****Suction and two sponge sticks (to compress the IVC if necessary) are readied and laparotomy sponges are placed around the renal vein to collect any spillage of tumor thrombus after opening of the renal vein. 
***'''Incise the renal ostium circumferentially using a scalpel or fine-tipped Metzenbaum or Potts scissors.''' 
***'''Extract the thrombus''' by gentle downward traction on the renal vein.
****A gauze is wrapped around the renal vein stump and secured with a silk ligature to prevent tumor spillage. 
***Dissect medial and other remaining attachments of the kidney 
***Deliver specimen 
*** '''Inspect the IVC for evidence of residual thrombus'''
***'''Close the IVC defect with a running closure using a 4-0 Prolene suture''' on a BB vascular needle.
****Prior to tying the knot, ask anesthesia to apply positive airway pressure, then pinch the infrarenal IVC closed and release the Satinsky clamp. Allow 5 to 10 mL of blood to escape from the caval defect to flush out any residual thrombus fragments and debris before pulling the suture tight and tying the closure.
***A regional lymphadenectomy is performed, irrigating the wound copiously with sterile water. 
***Consider placement of a closed suction catheter to monitor for bleeding. 

==== Level II vena caval thrombectomy ====

* Surgical plan (for left-sided tumor)
**Position: anterior midline and chevron incisions provide the best access for left-sided tumors associated with tumor thrombi in the IVC.
***'''Exposure for a tumor thrombus associated with a left-sided tumor is more difficult since the IVC is best accessed from the right retroperitoneum.''' 
****Both the right and the left colon have to be mobilized to get adequate exposure. 
**Medialize the left colon and develop anterior pararenal space. 
**Identify and ligate the left renal artery near its origin close to the aorta. 
**Identify and ligate the adrenal, lumbar, and gonadal branches of the left renal vein. These branches are often dilated and friable and occasionally contain thrombi. 
**Mobilize the kidney outside the renal fascia and divide the ureter. 
**Medialize the right colon, small bowel, and duodenum
**Develop the right anterior space
**Expose the great vessels.
**Carefully dissect the IVC to its bifurcation, ligating the right gonadal vein on its anterior surface.
***To gain 2 to 3 cm of extra infrahepatic IVC exposure, accessory hepatic veins are ligated to the caudate lobe (this is an optional maneuver).
**'''Obtain vascular control sequentially in the following order:'''
**#'''Ligate the ipsilateral (left) renal artery'''
**#'''Clamp the infrarenal IVC'''
**#'''Clamp the contralateral (right) renal vein'''
**#'''Clamp the suprarenal IVC'''
**##Optionally, one can clamp the contralateral renal artery to prevent renal engorgement while the venous outflow is temporarily clamped. 
**###More of an issue for left-sided tumors since unlike the left kidney, the right kidney does not have significant venous collateralization to shunt blood when the right renal vein is clamped. 
**##While obtaining vascular control, one must be very gentle to avoid dislodging the thrombus. 
**##Ligate and divide the lumbar veins, as required. 
**##Prior to clamping, some may use 0.5 mg/kg of intravenous heparin to prevent clamp-related thrombotic complications. This may increase bleeding and some do not routinely heparinize our patients.
**'''Excise the renal vein ostium circumferentially excised and extend the incision superiorly onto the anterior surface of the IVC using Potts scissors.''' 
***Use a Penfield dissector to carefully extract the tumor thrombus from the IVC. 
***Lumbar veins can be a source of troublesome bleeding at this stage and should be ligated or sutured as needed
**'''Remove the gross tumor thrombus and kidney en bloc.'''
**'''Irrigate IVC lumen with heparinized saline (100 units/mL) and inspect the intima for signs of caval invasion.''' Any suspicious areas should be biopsied or resected. 
**'''Close the caval defect with a running 4-0 Prolene suture.''' 
***'''The IVC lumen can be safely narrowed to about 50% of its preoperative size without requiring special measures.''' 
***'''Prior to tying the knot, the infrarenal clamp is released''' and 5 to 10 mL of blood is allowed to seep from the cavotomy to clear the IVC of air and debris. 
***'''After tying the suture, the contralateral renal vein clamp is released followed by the suprarenal IVC clamp.'''
* '''<span style="color:#ff0000">When performing right radical nephrectomy with tumor thrombectomy, the suprarenal IVC can be resected, but only if the left renal vein has been ligated distal to its venous tributaries (i.e., gonadal, lumbar, and adrenal veins). This will allow the left renal vein to drain through these tributaries. Given the lack of venous tributaries on the right side, the suprarenal IVC should not be resected for a left-sided tumor unless one provides alternative venous drainage for the right kidney with autotransplantation or a saphenous vein graft to the splenic, portal, or inferior mesenteric vein.</span>'''
* Regional lymphadenectomy is performed, consideration is given to leaving a closed suction drain, and the wound is irrigated and the incision closed.

==== Level III-IV vena caval thrombectomy: intra-abdominal approach ====

* Pre-operative planning
**Operating room should be set up for possible cardiopulmonary bypass (CPB), including deep hypothermic arrest. 
**Intraoperative TEE 
***Should be available to measure the cranial extent of the thrombus and to monitor the thrombus for fracture and embolization. 
***Cardiac function is evaluated with TEE so that the anesthesiologist can appropriately manage the patient’s hemodynamics.
* '''The key decision for level III thrombi is whether to attempt an intra-abdominal thrombus extraction with complete hepatic mobilization or use a combined intrathoracic/intra-abdominal approach with bypass.''' 
**This decision can only be made intraoperatively, after the renal artery is ligated, the liver is mobilized, and the IVC is exposed and evaluated. 
**It is preferable to clamp the IVC below the hepatic veins, since the venous return from the liver is significant. 
**As a rule of thumb, patents with free-floating partially occlusive thrombi will not tolerate suprahepatic clamping very well and should probably undergo bypass. Contrarily, patients with completely occlusive thrombi will typically have developed extensive collateral venous drainage networks and therefore tolerate clamping much better. 
**Occasionally, a level IV thrombus can be milked into the abdomen through a small diaphragmatic incision and treated intra-abdominally. 
**It is crucial that IVC control not compromise the operation since bleeding and hypotension can lead to an incomplete tumor resection, a result that is universally fatal. 
* Surgical plan
**Position: anterior midline incision for level III and IV thrombi; a chevron incision with added sternotomy can also be used. 
**Expose the right kidney and great vessels, as described for a level I thrombus
**Ligate the right renal artery is ligated in the interaortocaval area. 
**Dissect the infrahepatic IVC is gently. 
**Isolate the infrarenal IVC and left renal vein and Rummel tourniquets are placed around them.
**Mobilize the liver
***Ligate and divide the ligamentum teres, the remnant of the obliterated left umbilical vein that is located at the lower free border of the falciform ligament. 
***Divide the falciform ligament up to the upper border of the liver where it branches into the coronary ligament on the right and the left triangular ligament on the left. 
***Divide the superior layer of the coronary ligament with scissors or electrocautery, taking care not to injure the liver or the IVC, which is located just behind the ligament in the bare area of the liver. Division of the superior layer of the coronary ligament continues along the right border of the liver until it forms the right triangular ligament (the fused superior and inferior layers of the coronary ligament), which should also be divided. Mobilization of the right lobe of the liver is completed by dividing the inferior layer of the coronary ligament, the attachment that ties the liver to the diaphragm, upward toward the IVC.
***The left triangular ligament is divided anteriorly and hepatic mobilization is completed by dividing the posterior aspects of the left triangular ligament toward the IVC. The right lobe of the liver can now be safely and gently rotated toward the midline so that the IVC can be evaluated on the posterior surface of the liver. For tumors of the left kidney, it may be necessary to divide the diaphragmatic attachments of the spleen so that it can be rotated toward the midline with the pancreas without being traumatized.
**'''Develop the plane between the posterior surface of the liver and the anterior surface of the IVC.''' 
***The help of a hepatic surgeon with this portion of the procedure should be considered. 
***This plane contains venous branches from the liver that are divided into upper and lower groups. 
****The most important group is the upper group that contains the right, middle, and left hepatic veins, the principal outflow from the liver, and therefore cannot be divided. Tumor thrombus can extend into these veins and they must be carefully inspected and cleared of any thrombus during thrombectomy. Obstruction of these three veins leads to the Budd-Chiari syndrome. 
****The lower group of hepatic veins (the accessory hepatic veins) drain blood principally from the caudate lobe (with a small contribution from the right lobe) and can be safely divided. The accessory hepatic veins are ligated with 2-0 silk and the plane between the IVC and the liver is developed. 
***Additionally, the lumbar veins are ligated with 2-0 silk and the plane between the IVC and the posterior abdominal wall is developed. '''The IVC should now be fully mobilized.'''
**'''Create a  window in the lesser omentum and encircle the porta hepatis''' (also called the portal triad or hepatic pedicle)''', which contains the portal vein, common hepatic artery, and common bile duct, with a Rummel tourniquet.''' 
***Clamping the porta hepatis (the Pringle maneuver) is necessary to prevent massive blood loss if the IVC is clamped above the major hepatic veins. 
***Clamping the IVC above and below the hepatic veins while performing a Pringle maneuver is called total hepatic vascular occlusion. 
***If the IVC is clamped below the major hepatic veins and the accessory hepatic veins are ligated, the Pringle maneuver may not be necessary. 
***Under normothermic conditions, the porta hepatis can be clamped for up to 60 minutes, although a clamping time of 20 minutes or less is preferred since ischemic hepatic injury and portal vein thrombosis can ensue. Another complication of the Pringle maneuver is splenic engorgement and rupture as a result of backup of venous drainage from the splenic vein, which normally empties into the portal vein.
**'''Determine the resectability of the tumor and thrombus is using TEE and a thorough intraoperative assessment of the anatomy.''' 
***'''If the thrombus is below the hepatic veins or can be milked below these veins, it is usually safe to proceed without bypass.''' 
***'''If the thrombus involves the hepatic veins or extends above the liver, bypass is often required.''' 
**The IVC is occluded above the liver and thrombus and the patient’s hemodynamic response is observed over 2 to 5 minutes. 
***Clamping the suprahepatic IVC results in a 60% reduction in cardiac preload, an increase in peripheral vascular resistance of 80%, an increase in heart rate of 50%, a drop in cardiac output of 40%, and a drop in mean arterial blood pressure of 10% to 20%. If the cardiac output drops more than 50% or the mean arterial blood pressure drops more than 30%, the patient will not tolerate suprahepatic IVC clamping. Options for managing this situation include bypass (our preference) and clamping of the supraceliac aorta. 
***If the IVC clamping trial is tolerated and the thrombus can be removed in less than 30 minutes, it is safe to proceed with the intra-abdominal procedure.
**'''In sequence, the infrarenal IVC, the contralateral (left) renal vein, the porta hepatis, and the suprahepatic IVC are clamped.''' 
***For left-sided tumors, the right renal artery should be clamped prior to the right renal vein since there is no good collateral venous drainage for the right kidney. 
**'''Incise the ostium of the right renal vein is circumferentially and extend the incision toward the intrahepatic IVC.'''
***The incision should be large enough to permit extraction of all of the tumor thrombus and careful inspection of the intima of the IVC. 
**'''Excise the thrombus and kidney.''' 
***With the help of a Penfield dissector the IVC is cleared of adherent thrombus. 
****If involved with tumor that cannot be scraped away, the IVC should be completely or partially resected and reconstructed (see below).
***A Fogarty balloon catheter (Edwards Lifesciences Corporation, Irvine, CA) or 20-Fr Foley catheter can be used as an embolectomy catheter if the thrombus is out of reach.
**Close the IVC is closed as described for level II thrombus. The hepatic ligaments are tacked back into place to prevent torsion of the liver. 
**A regional lymphadenectomy is performed and a closed suction drain is inserted.

==== Level III-IV vena caval thrombectomy: combined intra-abdominal and intrathoracic approach ====

* Level III thrombi that cannot be removed intra-abdominally and most level IV thrombi are managed with a combined intraabdominal and intrathoracic approach. 
*Pre-operative planning
**A cardiothoracic surgeon needs to participate with the planned operation.
*Surgical plan:
**Thoracoabdominal, chevron laparotomy with sternotomy, and anterior midline laparotomy with sternotomy incisions can be used to provide access to the chest and abdomen
**Abdominal portion of the case is identical to the intraabdominal approach described above. 
**Once the abdominal phase is completed, the cardiothoracic surgeon is called to the operating room and a median sternotomy is performed. The pericardium is opened and the right heart exposed. Often, mobilization of the liver and IVC is easier once the sternotomy is completed.
**Obtain bypass using one of the techniques described below. 
**Once on bypass, the ostium of the renal vein is circumferentially excised, the incision is extended cranially on the IVC, and the thrombus is extracted. 
**A right atriotomy is usually performed to help remove the suprahepatic thrombus. 
**The atrium and IVC are then closed. 
**The patient is taken off bypass and thoracotomy tubes and closed suction abdominal drains are placed. 
**The hepatic ligaments are tacked back into place to prevent torsion of the liver and regional lymphadenectomy is performed.

* '''Bypass techniques for IVC surgery'''
** '''Bypass should be considered in patients in whom the IVC cross-clamping trial causes significant hypotension, as well as in patients in whom there is preoperative cardiac or hepatic dysfunction, contralateral renal dysfunction, or portal venous hypertension, and when there is major intraoperative bleeding that is difficult to control.'''
** '''Venovenous bypass'''
*** '''Involves shunting the venous blood from below the renal veins to the venous return of the heart with the aid of a pump'''
*** '''Advantage'''
****'''Least invasive bypass technique for IVC thrombi;''' can be done without opening the chest, unlike traditional cardiopulmonary bypass.
*** 2 main options are available for infrarenal cannulation: 
****Percutaneous approach through the femoral vein
****Direct intraoperative approach through the IVC just above its bifurcation. 
*****When cannulating the IVC, it is important to position the tip of the cannula as far from the tumor thrombus as possible to avoid dislodging it, which can cause a massive pulmonary embolism, and to avoid aspirating and recirculating tumor cells.
*** Several options are available for delivering the shunted blood back to the heart: a percutaneous approach via the internal jugular vein, a cutdown approach to the brachial/axillary vein, and a direct intraoperative approach through the right atrium.
** '''Cardiopulmonary bypass +/- deep hypothermic arrest'''
*** '''Cardiopulmonary bypass can be performed with or without deep hypothermic arrest.''' 
****'''Cardiopulmonary bypass with deep hypothermic arrest involves stopping the heart and starting bypass, cooling the patient to 16° C to 18° C, and draining all of the blood from the patient.''' 
*****Advantages
******Can be used in cases in which the thrombus cannot be milked below an intrapericardial IVC clamp
******No need to clamp the aorta or porta hepatis or to ligate as many lumbar and hepatic veins since blood flow to these structures is no longer present. However, all vessels that have been traumatized or transected must be controlled since they will bleed once the patient is taken off bypass. 
******Absence of active blood flow allows for complete inspection of the IVC and hepatic veins, thereby aiding in achieving a complete thrombectomy. 
******Risk of embolization during thrombectomy is lower.
******'''Purpose of deep hypothermic arrest is to reduce organ metabolism, allowing for greater duration of absence of blood flow'''
*******At normothermia, brain injury occurs after approximately 4 minutes of circulatory arrest. Most patients tolerate 30 minutes of deep hypothermic circulatory arrest without significant neurological dysfunction. Above 60 minutes, the majority of patients will suffer irreversible brain injury.[https://academic.oup.com/bjaed/article/10/5/138/274654]
*****Disadvantage
******Very invasive
***** Surgical plan:
******Mobilize the kidney and dissect IVC. 
******The cardiothoracic surgeon performs the sternotomy, opens the pericardium, and exposes the heart and its vessels. 
******Heparin-bonded cannulae are placed in the infrarenal IVC and the right atrium to collect venous blood and a cannula is placed into the aortic arch for outflow. 
******The patient is heparinized and bypass is started. 
******The aorta is clamped and cardioplegia solution is administered. 
******The temperature of the recirculated blood is dropped to 10° C to 14° C and the patient is cooled for 15 to 30 minutes until a core temperature of 16° C to 18° C is reached. 
*******Intraoperative electroencephalography should be performed to determine when the brain has been adequately cooled. 
******When sufficient cooling has been achieved, the perfusion pump is stopped and 95% of the patient’s blood volume is drained into the pump reservoir. 
******Tumor thrombectomy should be performed as fast as possible, taking great care to ligate all potential bleeders. 
*******If the resection is taking longer than anticipated, the surgeon should consider allowing a 10-mL/kg/min trickle of blood to flow to the organs or using retrograde cerebral perfusion.
******If the patient has known coronary artery disease, coronary artery bypass can be performed at the same time. 
****** Once the IVC and right atrium are repaired, warm blood is reinfused from the pump reservoir and cardiopulmonary bypass is restarted. 
******Hemostasis is performed while the patient warms to 37° C over the next 30 to 45 minutes. 
******Once the heart has restarted pumping, bypass is stopped, the cannulae are removed, and protamine sulfate is administered.
******'''<span style="color:#ff0000">Most common difficulty associated with hypothermia and circulatory arrest is hemorrhage associated with platelet and clotting factor dysfunction</span>'''
*******Fresh frozen plasma, platelets, and packed red blood cells should be available to administer. 
******Thoracostomy tubes and closed suction abdominal drains are inserted.
*** Alternatives to CPB may include venovenous bypass and extensive liver mobilization
* '''<span style="color:#ff0000">Patching, replacing, and interrupting the IVC</span>'''
** '''<span style="color:#ff0000">Patch Cavoplasty</span>'''
*** '''<span style="color:#ff0000">If the IVC lumen is expected to be < 50% of its original size, a patch cavoplasty is necessary to prevent IVC stenosis and thrombosis-related events</span>'''
*** Autologous and bovine pericardium, polytetrafluoroethylene (PTFE), collagen-impregnated Dacron (DuPont, Wilmington, DE), and autologous saphenous vein are materials that can be used for patch cavoplasty.
** '''Vena caval replacement'''
*** In situations when a circumferential section of IVC has been removed or if a vena cava defect is too large for simple patching, vena caval replacement is necessary
*** Typically, PTFE grafts are used to replace the IVC, although others have described spiraled saphenous vein, superficial femoral vein, and tubularized pericardium as options
*** '''Postoperatively, low-dose intravenous heparin or a reduced dosage of low-molecular-weight heparin is given.''' Once the patient’s bowel function has recovered, lifelong oral warfarin is used with a target INR of 2 to 3.
* '''IVC filtration and permanent interruption for bland thrombus'''
** Occasionally, a patient with an infrarenal bland thrombus requires management at the time of tumor thrombectomy.
** For bland thrombus that is limited to the pelvic veins, intraoperative placement of an infrarenal vena cava filter is indicated.
** For bland thrombus that diffusely involves the infrarenal IVC, the optimal management is permanent interruption of the IVC. 
***Necessary intraoperative care is required to preserve the collateral lumbar venous drainage, since these vessels provide a “release valve” for the impaired caval blood flow. 
***Options for permanent interruption of the IVC include serrated vena cava clips (e.g., Adams-DeWeese clip, Moretz clip), cross stapling with a vascular GIA stapler (Covidien Ltd., Mansfield, MA), suture plication, and suture ligation.
* '''<span style="color:#ff0000">Perioperative complications</span>'''
** '''Air embolism'''
*** Potentially lethal
*** Risk of air embolism can be significantly reduced by releasing the caudal IVC clamp first and allowing air and some blood (5 to 10 mL) to escape from the IVC repair site prior to removing the cranial clamp.
** '''Acute PE'''
*** Tumor and bland thrombus can embolize during and after surgery. Minimizing intraoperative manipulation of the kidney and IVC before vascular control helps reduce the likelihood of acute thrombotic pulmonary embolism.
*** If respiratory distress is encountered during surgery, strong consideration should be given to prompt thoracotomy, pulmonary arteriotomy, and extraction of the thrombus.
** '''Massive hemorrhage'''
*** Major bleeding can occur during and after the surgery. If uncontrolled major bleeding occurs in a patient who is not on bypass, the surgeon should consider clamping the aorta above the celiac trunk or initiating deep hypothermic CPB
** '''Hepatic dysfunction'''
*** Temporary hepatic dysfunction, characterized by elevated transaminases and alkaline phosphatase, is common in patients with levels III and IV thrombi that require suprahepatic IVC clamping and/or bypass.
*** Liver enzymes typically peak 2 to 3 days postoperatively and slowly resolve thereafter.
** '''Organ ischemia'''
*** Cardiac ischemia is most common in patients undergoing suprahepatic IVC clamping without bypass.