**9. Other developments and issues**

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

With regard to dealing with the IVC intraoperatively is one of the difficulties of IVC throm-

Indications for vena caval interruption include invasion of the venous walls, severe adhesion of the tumor to the vascular endothelium, complete occlusion of the vena cava, and the presence of distal thrombus [21, 39, 40]. In addition, the texture of the cancer thrombus is one of the influencing factors. With regard to preoperative imaging, the IVC in line with the indications of interruption and accompanied by sufficient collateral circulation, meanwhile, without serious cardiac, hepatic, and renal insufficiencies can be completely cut off. IVC venography and intraoperative ultrasound can help determine the disjointed lumina, which enables protection of the established collateral circulation trunk. IVC interruptions include complete and partial vena caval resections with reconstruction. Based on our experience, for right tumors, the height of the tumor thrombus, which is below the secondary hepatic portal, linear cutters are used to successively cut off the proximal, distal, and left renal veins of the tumor thrombus (**Figure 1I**). With regard to right tumor thrombus above the secondary hepatic portal, or left tumor thrombus above the level of the right renal vein and combined with distal thrombus, the vena cava can be resected partially. Methods for right thrombectomy include cutting off the lumina of the IVC below the secondary hepatic portal and reconstructing the lumina of the IVC above the secondary hepatic portal. The left thrombectomy procedure is resecting the lumina of the IVC below the level of the right renal vein and reconstructing the lumina of the IVC above the level of the renal vein.

Meanwhile, IVC interruption is safe and feasible during vena caval thrombectomy [39, 40], and the establishment of collateral circulation can avoid severe hemodynamic disorders. Different strategies of interruption ought to be generated preoperatively based on the height of tumor thrombus, tumor side, degree of vena caval obstruction and invasion, and establish-

Vena cava tumor thrombus with thrombosis is common. The prevalence of thrombosis gathered by the Urological Department of Chinese PLA General Hospital is 19.2%. Thrombosis, at the same time, is not found within the renal venous tumor thrombus; all thrombosis occurred in the vena cava tumor thrombus. Among them, vena caval thrombi were all located on the right, the thrombus was located in the distal end of the tumor thrombus, and the distal thrombus could reach the bifurcation of the iliac vessel. Preoperative MRI can help determine the

**8. IVC tumor thrombus with thrombosis and treatment** 

**7. Indications and strategies of intraoperative IVC interruption**

bectomy. There necessity of reconstruction after IVC resection is still controversial.

azygos, which might interfere with the surgery.

204 Evolving Trends in Kidney Cancer

ment of collateral circulation.

location and length of the thrombus.

**recommendations**

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 be conducted.

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

Finally, although RCC invades the venous system to form tumor thrombus, the tissue components between the primary tumor of the kidney and the tumor thrombus has a large difference. Meanwhile, heterogeneity exists in primary RCC and tumor thrombus, which may be the reason why primary tumor and tumor thrombus response to preoperative targeted therapy was asynchronous, and drugs among different patients respond differently. Therefore, the research of heterogeneity between primary RCC and venous tumor thrombus may find a more effective therapeutic target and drug for the reduction of tumor thrombus level, which can provide the basis for selecting appropriate patients for neoadjuvant targeted therapy preoperatively.

**Acknowledgements**

(2014AA020607).

**Author details**

, Liangyou Gu†

Songliang Du, Xu Zhang\* and Xin Ma\*

Cheng Peng†

**References**

115-132

2011;**37**(5):422-428

2013;**82**(1):136-141

†

**Conflict of interest**

This work was supported by the People's Republic of China and the National High Technology Research and Development Program ("863" Program) of China: the screening and clinical validation of characteristic protein biomarkers in renal cancer based on a large-scale biobank

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

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

207

, Luojia Yang, Baojun Wang, Qingbo Huang, Dan Shen,

The authors have declared that they have no conflict of interest.

Hospital/Chinese PLA Medical Academy, Beijing, P. R. China

the vena cava. Journal of Urology. 2002;**3**(1):37-43

These authors contributed equally to this work.

\*Address all correspondence to: urologist@foxmail.com and xzhang@foxmail.com

Department of Urology/State Key Laboratory of Kidney Diseases, Chinese PLA General

[1] Chen WQ et al. Cancer statistics in China. CA: A Cancer Journal for Clinicians. 2016;**66**(2):

[2] Hatcher PA et al. Surgical management and prognosis of renal cell carcinoma invading

[3] Parra J et al. Oncological outcomes in patients undergoing radical nephrectomy and vena cava thrombectomy for renal cell carcinoma with venous extension: A single-centre experience. European Journal of Surgical Oncology. The Journal of the European Society of Surgical Oncology & the British Association of Surgical Oncology.

[4] Haferkamp A et al. Renal cell carcinoma with tumor thrombus extension into the vena

[5] Kaushik D et al. The impact of histology on clinicopathologic outcomes for patients with renal cell carcinoma and venous tumor thrombus: A matched cohort analysis. Urology.

cava: Prospective long-term followup. Journal of Urology. 2007;**177**(5):1703

## **10. Future perspectives**

Open IVCTE is still a standard surgery for RCC with IVC thrombus. With the development of laparoscopy and robotic technology in recent years, the safety and feasibility of robotassisted laparoscopic IVC thrombectomy have been investigated at several centers. Those successful experiences mark that such surgery tends to enter the era of mini-traumatic surgery. Considering the complexity of the patient and the high complication rates, multidisciplinary cooperation and detailed preoperative assessment will play an important role in surgical decisions in future. Some new or mature techniques will also provide a basis for the surgical strategies, including artificial blood vessel, augmented reality, transesophageal echocardiography, IVC venography, and so on. From a safety perspective, IVCTE is still a challenging technology. Only a hospital with skilled laparoscopic and mature surgical team is recommended. Preoperative TMT is expected to shrink the IVC thrombus and reduce the complexity of the surgery. However, prospective investigations are required in the future.

#### **11. Conclusions**

RCC tends to invade the venous system and form venous tumor thrombus in 4–10% of patients. Surgical treatment is the standard therapy for these patients; however, postoperative complications include hemorrhage, thrombotic shedding, and other risks. Because of the huge population and relatively backward treatment concepts, the proportion and number of patients with advanced RCC in China are significantly higher than those in developed countries, such as Europe and the United States. With regard to patients with RCC and tumor thrombus, the strategies for diagnosis and treatment are mostly based on open surgery. Several clinic-related strategies are no longer suitable for current laparoscopic and robot-assisted mini-traumatic surgeries owing to the development of surgical techniques and improvement of auxiliary equipment. With regard to the tumor thrombus, a series of retrospective and prospective studies are needed to be conducted, which would enable to solve some difficulties and issues in the course of diagnosis and treatment, to improve the clinical strategies of diagnosis and treatment of patients with RCC and tumor thrombus ulteriorly, and to provide our clinical work with more powerful reference and basis.
