**6. Strategies and indications of IVC venography**

**4. Preoperative targeted therapy**

Retrohepatic and closer (level II) or above (level III)

the second porta hepatis (liver vein) yet

infra-diaphragm

202 Evolving Trends in Kidney Cancer

method.

**Location of IVC thrombus Surgical strategy** Retrohepatic but inferior to the FPH 1. Ligating some SHV

Retrohepatic and between the FPH and hepatic veins 1. Ligating more SHV

IVC = inferior vena cava; SHV = short hepatic vein; FPH = first porta hepatis.

Although mini-traumatic surgery has been applied in patients with RCC and tumor thrombus, level III and IV tumor thrombus might have lethal complications, including hemorrhage, thrombotic shedding, etc. The operative mortality and overall morbidity rates of postoperative complication of patients with tumor thrombus patients have been reported up to 5–10% and 38%, respectively [21]. Moreover, as tumor thrombus level advanced, the morbidity of perioperative periodical complications is higher accordingly. With regard to patients with level III and IV tumor thrombus, surgical strategies usually involve thoracotomy, dealing with retro- or superohepatic IVC, and establishing extracorporeal circulation, which can be

**Table 2.** Changes of techniques for robot-assisted retro- or supero-hepatic vena caval tumor thrombectomy in our

Superohepatic (level IV) 1. Thoracoscopic atriotomy for cutting atrial part of the

2. Retracting but not liver mobilization

2. Mobilizing the right lobe of the liver.

2. Establishing cardiopulmonary bypass

superodiaphragm IVC

1. Mobilizing both the right and left lobes of the liver 2. High proximal control of superohepatic IVC 3. Clamping of the FPH Simultaneously

3. Performing IVC tumor thrombectomy after Clamping the

3. Not clamping FPH

thrombus

With the targeted molecular therapy (TMT) of rising, TMT has been widely acknowledged as the most effective treatment for advanced RCC, particularly for patients with metastatic RCC. In recent years, targeted drugs have been reported to be applied in preoperative adjunctive therapy for tumor thrombus because of its high success rate in the treatment of advanced RCC [22, 23]. The purpose of administering target drugs was to lessen the height of tumor thrombus or shrink the primary lesions or metastases, which may enhance the safety and feasibility of surgical intervention. The results of some retrospective observations with a small sample present diversities [24–26]. After preoperative TMT, 44–76% of the patients' IVC tumor thrombus had shrinkage in different degrees, with tumor thrombus degradation averaging approximately 20%. Cost and colleagues reported a retrospective outcome from a sample of 25 patients, wherein three patients (12%) had a reduction in the thrombus degradation, and one patient (4%) had an increase [25]. As a result of first-class evidence deficiency, this therapeutic regimen has not been recommended by the guidelines. Thus, further prospective investigations with a larger number of patients are needed to overcome the limitations.

achieved with the assistance of hepatobiliary and cardiovascular surgeons.

Sufficient preoperative imaging data is requisite for successful thrombectomy. However, several problems in the imaging diagnosis of IVC tumor thrombus still exist: Type-B ultrasound has difficulty in accurately diagnosing abnormal changes owing to numerous interferences. Magnetic resonance imaging (MRI) and computed tomography cannot effectively reflect the collateral circulation, and cannot define the degree of occlusion [35]. Therefore, more effective means are required to supplement these three routine examinations. IVC venography can observe the thrombus occlusion through the lateral position, which enables to maximize a rich data of tumor thrombus preoperatively and to make a more accurate surgical plan.

IVC venography has been widely used in the diagnosis of Budd-Chiari syndrome and other diseases [36]. There are still more applications in renal cancer with IVC tumor thrombus yet. Some studies reported that <15% of cases of patients with cancer thrombus would use IVC venography, and some researchers previously thought that the inspection might have falsepositive or false-negative results. Meanwhile, there is a risk of emboli-induced pulmonary embolism or tumor embolus exfoliate diffusion. Therefore, performing IVC venography routinely is not recommended [37, 38].

However, with the improvement of radiographic technique in recent years, the safety of IVC venography has been observably improved, and this method may define the formation of collateral circulation of the vena cava and help develop a thrombectomy strategy, which has unique diagnostic advantages. Hence, conducting a new study for IVC venography is necessary. Based on our experience, we speculate that the following patients may be a candidate for IVC venography: (1) RCC with IVC tumor thrombus; (2) clearance of the tumor thrombus plane; (3) definition of the degree of occlusion; (4) existence of collateral circulation, which may affect intraoperative vascular resection; (5) detection of the variation of the communicating branches of vena cava, such as the variation communicating between IVC and vena azygos, which might interfere with the surgery.

Preoperative anticoagulation therapy is recommended for patients with thrombosis, and medication should be administered from the diagnosis of tumor thrombus and thrombus. Low-molecular heparin is recommended for anticoagulation therapy, withdrawing drugs 24 h preoperatively, maintaining the international normalized ratio of 2–3, and anticoagulation therapy is continued for 48 h postoperatively and maintained for 6 months, except for the following: patients with tumor or tumor thrombus who did not undergo complete resection; those with metastasis; needs for systemic treatment; and patients with pulmonary embolism. Pre- and postoperative placement of the vena cava stent is not recommended only if the patient has pulmonary embolism and contraindications of anticoagulation therapy [41, 42]. Preoperative imaging examinations are required for patients with extensive thrombosis at the distal end of the tumor thrombus [43]. IVC interruption is recommended, which prevents embolization caused by thrombus shedding, for patients who meet the indications and pos-

Surgical Strategy for the Management of Renal Cell Carcinoma with Inferior Vena Cava Tumor Thrombus

http://dx.doi.org/10.5772/intechopen.73294

205

Besides the previously mentioned issues, some problems need to be solved in the field of RCC with tumor thrombus. First, whether the tumor thrombus is invading the venous walls is an important issue in diagnosis and treatment process to decide on the preoperative surgical strategies. Furthermore, it may also relate to postoperative survival. However, because the diagnostic criteria of imaging and pathology are currently insufficient, further studies should

Second, the survival of patients with RCC and venous thrombus postoperatively was significantly worse than those with localized RCC, particularly in patients with preoperative distant metastases. For IVC tumor thrombus, particularly patients with level III–IV tumor thrombus, the perioperative risk and mortality are higher. At the same time, although some patients completed the radical resection of tumor, survival after surgery is still less than 6 months. Therefore, for patients with high surgical risk or short life expectancy, the necessity for surgery deserves further discussions. The prognosis of patients with RCC and venous tumor thrombus, at present, lacks the preoperative predicting models particularly related to imaging features. The study of preoperative imaging characteristics of tumor thrombus and biological behavior of the tumor and the prognosis of patients may provide some guidance for preoperative choice of treatment.

Augmented reality (AR) is a real-time technology to calculate the location and angle of the camera images and add corresponding images. The goal of this technology is to set the virtual world in the real world and interact with it on screen [44]. Based on individual anatomy, the AR and computer system have been used in partial nephrectomy as a new technology *in vivo* and *in vitro* [45–47]. To overcome the problem of soft tissue and organ shift, Teber and colleagues reported a new navigation approach added to endoscope that was used in laparoscopic partial nephrectomy [47]. The study showed that the new AR tracking system proved to be effective, with a reasonable margin of error and a time to match each other. In addition, combining pre- or intraoperative imaging features with real-time endoscopy will simplify and increase the accuracy of laparoscopic surgery [47]. Thus, AR combined with three-

dimensional vision has a great application value in robotic surgery in the future.

sess sufficient collateral circulation.

be conducted.

**9. Other developments and issues**
