Treatment of Renal Cell Carcinoma

## **Chapter 4**

## The Three-Dimensional Virtual Surgical Simulation and Surgical Assistance for Optimizing Robotic Partial Nephrectomy

*Shuji Isotani*

## **Abstract**

Robot-assisted partial nephrectomy (RAPN) has been accepted as the standard treatment recommended for relatively small renal mass or even the T2 renal carcinoma in experienced hospitals as Nephron Sparing Surgery. To obtain better RAPN surgical outcomes, the understanding of surgical anatomies such as the position of intrarenal structure and the positional relationship of each structure should be detailed in a three-dimensional (3D) manner. The 3D virtual surgical simulation for partial nephrectomy based on the image segmentation method with high-resolution CT can provide the 3D anatomical details of the renal tumor focusing on their relationships with the arterial and venous branches as well as with the intrarenal portion of the urinary collecting system. This imaging application is also used as image guidance during the surgery, and it indicated that it provides the improvement of clinical outcomes such as the duration of hospitalization, transfusion, and major postoperative complications as well as conversion to radical nephrectomy or open partial nephrectomy. In this chapter, we describe the basics of the 3D imaging assistance methods for partial nephrectomy and the benefit of 3D virtual surgical simulation in optimizing the outcome of the RAPN.

**Keywords:** partial nephrectomy, robot-assisted partial nephrectomy, segmentation, 3D surgical simulation, image-guided surgery

### **1. Introduction**

The number of stage 1 renal cell carcinoma has shown a significant increase in this decade. This trend was been brought by the improved modality of the screening imaging technology, such as ultrasound or CT imaging. The surgical treatment has been recognized as the standard surgical procedure for the treatment of early-stage renal cancer. Nephron sparing surgery (renal function-preserving surgery) has become the recommended treatment option for small-diameter renal tumors (small-diameter renal cancer) [1]. Comparing the oncological results after radical nephrectomy and partial nephrectomy, the outcomes of both surgical methods are equivalent; in addition, partial nephrectomy provides better preservation of renal function [2]. With

partial nephrectomy, it may be considered lower the risk of cardiovascular and metabolic sequelae that would eventually turn into better overall survival for the patient comparing radical nephrectomy [3–5]. Therefore, at present, Nephron sparing surgery is positioned as the standard treatment for T1 small-diameter renal cancer. Partial nephrectomy is preferred for the following T1a tumors, and partial nephrectomy is recommended for T1b tumors between 4 and 7 cm, if possible [1, 6, 7]. Robot-assisted partial nephrectomy (RAPN), in particular, with the high-resolution 3D stereoscopic view and with multiple joints in robotic arms has been reported to have better treatment results than open surgery and laparoscopic surgery, such as preservation of function and reduction of perioperative complications [8, 9]. Today, at high-volume centers, the indication for partial nephrectomy has been gradually expanding with the robot-assisted procedure for selectedT2 cases. With increased tumor size and stage, PN becomes more challenging surgery, it may result in a higher risk of perioperative complications such as severe blood loss, urinomas, and arteriovenous fistulas. These are known as "Risk benefit trade-offs between partial and radical nephrectomy", so it was recommended that PN indication for large tumor should be considered more selective, and specific for patient and tumor factors [7, 10].

#### **Figure 1.**

*The comparison of two-dimensional (2D) images of CT with axial (a), coronal (b), and sagittal (c) images and 3D CT volume rendering image (d).*

#### *The Three-Dimensional Virtual Surgical Simulation and Surgical Assistance for Optimizing… DOI: http://dx.doi.org/10.5772/intechopen.108773*

Partial nephrectomy is a procedure that cuts into the blood-rich renal parenchyma, requiring complete excision of the tumor and precise repair of damaged renal structures. It was demonstrated that the degree of difficulty varies depending on the patient factors such as comorbidities or anatomical factors, and operators skillset and the learning curve is relatively long comparing other urological operations [9–12]. Due to the complexity of surgical procedure, it is considered that presurgical evaluation and surgical planning are quite important for each case. Surgeons should understand the surgical anatomy of the target kidney and tumor, especially, the position of renal structure, and the positional relationship of each structure should be known in order to optimize the surgical technique and achieve better surgical outcomes [10]. For a detailed understanding of the relationship of the hilum to the anatomy, it has previously been performed using two-dimensional (2D) image data (coronal, sagittal, and axial images) of computed tomography (CT) volume rendering for evaluation of these anatomical factors (**Figure 1a**–**c**) [13, 14]. Surgeons had to use their cognitive abilities to simulate the anatomy of the kidney and tumor as three-dimensional information while referring to those 2D images. For experienced urologists, it was probably easy to recall 3D information from 2D images; however, it is unclear whether all urologists can accurately reproduce the detailed anatomy and its complexity. Since 2012, there have been many reports to describe the befit of 3D CT volume rendering images for partial nephrectomy as the surgical support (**Figures 1d** and **2a**) [13].

However, only by the 3D-CT volume rendering, it was difficult to extract the urinary system or renal vein ant tumor at the same time, and it also enables to perform the volumetric analysis. To overcome the difficulties of 3D-CT volume rendering, one imaging technique called "segmentation" was developed as the image processing method (**Figure 2b**).

The segmentation process identifies the position information of each part of the organ and extracts one organ as a segment. Because the intrarenal anatomical structures of the kidney can be opaqued or removed as 3D models, interactive anatomical evaluation can be performed. It becomes possible to visualize the physical structure [15]. Since 2015, the Department of Urology, Juntendo University, has been using segmented

#### **Figure 2.**

*The comparison of 3D CT volume rendering image (a) and 3D segmented image (b). With 3D CT volume rendering image, it is difficult to distinguish renal organs at one glance. The 3D segmentation makes it easy to recognize the renal organs. This imaging process developed one step further to "image understanding" by recognizing organs as 3D images volume matrix.*

3D images based on preoperative CT images to understand the anatomical complexity of renal tumors in RAPN and has been useful in preoperative planning [15, 16]. Furthermore, this imaging technology can also be used for surgical navigation during surgery and is extremely useful as an image reference during the actual surgery.

In this chapter, I will discuss the imaging technique for optimizing Robotic Partial Nephrectomy in surgical simulation and surgical assistance using 3D virtual surgical simulation.

## **2. Renal anatomical structures and 3D Segmentation**

As mentioned earlier, at the partial nephrectomy, the surgeon cuts into the bloodrich renal parenchyma and removes the tumor and repairs damaged renal structures without hemorrhage and urine leakage. During all these processes, the surgeon needs to understand the detailed anatomy of the vasculature (renal artery and renal vein), urinary system, renal cyst, tumor(s), and other structures within or surrounding the kidney (**Figures 2b**, **3** and **4**).

In general, the renal artery is reaching from the main renal artery to the segmental artery, the interlobar artery, the arcuate artery, and the interlobular artery branch to the glomerulus. The anatomical distribution of renal arteries is divided into five segments including an apical, upper, middle, lower, and posterior segmental artery. Because each artery does not have adequate collateral circulation, the ligation of the segmental artery causes irreversible ischemia in that area of blood supplied by teach segmental filed [10, 13, 17].

This anatomical feature allows the surgeons to segmental resection only by segmental ischemia at the partial nephrectomy. All segmental branches arise from the anterior segmental artery, except for the posterior segmental branch, which arises from the posterior segmental artery. However, there are some anatomical variations are known in the distribution of the renal arteries. In the variation, the lower renal segmental artery may arise from the main renal artery. Also, there may an accessory artery also known as multiple renal artery or duplicate renal artery that arises from the

#### **Figure 3.**

*At the segmentation process, renal anatomical structures the anatomical structures (aorta, renal artery, IVC, renal vein, kidney, urinary system, tumor, and other structures within or surrounding the kidney) are extracted from a different phase CT data using image recognition algorithm.*

*The Three-Dimensional Virtual Surgical Simulation and Surgical Assistance for Optimizing… DOI: http://dx.doi.org/10.5772/intechopen.108773*

**Figure 4.**

*3D structural images are combined together into one 3D image with registration technology. The extracted anatomical structures can change their transparency of the structural image for the easiest understanding, also organ volume such as tumor volume or renal volume can be calculated.*

abdominal aorta directly and does not pass through the renal hilum [10]. The multiple renal arteries are regarded as the persistent embryonic lateral splanchnic arteries. The renal artery originally had multiple supply vessels from the aorta to the mesonephros during embryogenesis, but during the development process, two or more supply vessels remained on one side. The frequency of these duplicated renal arteries is estimated at 15% [10]. These anatomical variations of renal arteries have a great impact on actual partial nephrectomy surgery. If the surgeons know the detailed information about the anatomical distribution of the renal artery and operation time can be shortened and become safer and more reliable. The segmental clamping technique is one of the promising procedures to reduce the renal ischemic damaged area to preserve renal function. For effective segmental arterial clamping, the surgeon needs to identify the renal target artery in a 3D manner to get the essential ischemia damage for the resection of the tumor. Gill et al. reported super-selective arterial clamping in 2012 as the anatomical partial nephrectomy [18]. They used 3D segmentation to get the semitransparent tumor and renal arterial branches remain opaque. The 3D segmentation made it possible to see interrelationships of tumor vis-à-vis intrarenal segmental arterial branches, and such anatomical detail was necessary to operate on challenging tumors. The 3D segmentation is a medical image-aided tool that provides localization and assessment of organ size and shape. Kidney segmentation involves identifying the location information of each part of the kidney from high-definition CT, etc., and extracting one organ as a segment (**Figure 3**). The original computational 3D segmentation tool in developed in Japan in 2012 for the liver extraction tool and has been applied to the kidney in 2014 by Komai et al. [19]. In the past few years, 3D segmentation analysis for renal surgery has been applied in many countries, and it has been reported in some literature [19–24]. Today, with the computational algorithm, it is relatively easy to extract blood vessels from arterial phase CT imaging data. The renal arteries below 2 mm diameter and renal vessels are able to 3D segmentation by image recognition algorithm using the computer automatically. Also, the renal parenchymal and cortical regions can be extracted by the computational calculation with imaging software automatic tracing the edge of each kidney from CT images. The various image recognition algorithms were reported by researchers [19–24]. In addition, not only the blood vessels but also the renal tumor, the ureter, or the renal pelvis can be extracted automatically by using image recognition algorithms from the urography phase.

By combining extraction of the liver, bone, and body wall, now the surgeon can virtually reproduce all organ imaging required for performing the renal surgery by himself (**Figure 4**). The 3D segmentation processing improved medical imaging one step further to "image understanding," in other words "imaging diagnosis" by recognizing organs as 3D images volume matrix. By performing 3D segmentation processing, the 3D map of the kidney organs can be produced as the computational volume data. Since it is the computational volume data, it is possible to modify the visualization interactively and calculate the image volume easily. The anatomical structures can be seen by changing the transparency of the structural image, and each organ volume such as tumor volume or renal volume is calculated. In addition, image processing such as measuring and comparing the volume and cutting out the surroundings at a certain distance is possible.

## **3. 3D-virtual surgical simulation and 3D-image guided surgery**

The idea of simulating surgery using medical images has been examined for a long time; however, it has rapidly progressed and spread in this decade.

The reason for this progress is the improvement in computational power used for image processing and the development of 3D image-processing software. They have become more powerful and cheaper than before, and they have come to be offered as affordable medical equipment. The 3D-virtual surgical simulation consists of the following four steps [1]. The first step is acquiring CT DICOM data and importing the imaging data to the image-processing software [2]. The second step is the

*In the surgical simulation, the surgeon can simulate the width of the resection margin size and resection method. Setting the cut surface with an optimal tumor margin with (a) resection margin; 1 mm, (b) resection margin; 5 mm, (c) resection margin; 10 mm. The surgeon can predict the involvement of the urinary collecting system or vascular system on the cutting surface by surgical simulation. The simulated resection volume and residual parenchymal volume can be calculated by CT volumetry.*

### *The Three-Dimensional Virtual Surgical Simulation and Surgical Assistance for Optimizing… DOI: http://dx.doi.org/10.5772/intechopen.108773*

segmentation of the renal structures (renal artery and renal vein, urinary system, renal cyst, tumor, and other structures within or surrounding the kidney) from a different phase of CT data, by imaging software (**Figures 3** and **4**) [3]. Then we perform 3D-virtual surgical simulation using the imaging software. With the software, we can simulate the two different resection methods, the enucleation technique and wedge resection technique, with any surgical margin size setting (**Figure 5**, Video 1). In the enucleation setting, the surgeon can simulate the width of the resection margin size for virtual enucleation. At the wedge resection setting, the surgeon can perform the simulation with setting by both the cut angle and resection margin for virtual resection. We can predict the involvement of the urinary collecting system with surgical simulation. If the urinary collecting system appeared on the planned cut surface, it means that the urinary collecting system was involved in the resection field, and the surgeon needs to decide to cut the collecting system or gently peel away it from the tumor. The imaging software also can calculate each resection volume based on CT volumetry and residual parenchymal volume of the healthy kidney [4].

The final step is the assessment of the arterial supply area for selective clamping. It is the computational approximation of vascular territories based on Voronoi decomposition. With this computational 3D Voronoi decomposition, renal arterial territories were calculated according to each arterial branch as the central point of the blood-supplied segment (**Figure 6**, Video 2).

For the 3D-image guided surgery, we connect the imaging software to the da Vinci system through digital video interface (DVI) input ports (**Figures 5** and **6**). We can see the real-time 3D-image surgical simulation on the surgeon's console of the da Vinci surgical system as the reference, using TilePro multi-input display. Initially, the surgeon's console display of the da Vinci shows the endoscopic view. In the use of TilePro, the images of 3D-image surgical simulation simultaneously appeared just

#### **Figure 6.**

*The vascular territory (light green area) belonging to the selected targeted artery (light green arrow) branch is shown in a color-coded 3D model. The patient had five right renal arteries and a 2.5 cm tumor on the lateral side of the mid-renal pole. Vascular image analysis was performed to identify to know which artery supplied the tumor. Vascular analysis revealed that the second renal artery (light green arrow) is the only target artery to supply the tumor and 3 mm resection margin, so in this case, surgery was performed with a selective clamping technique on the targeted second artery only (the light green point was target point). The operation was safely completed without the need for an additional vascular clamp or blood loss.*

below the standard endoscopic view (**Figures 7**–**9**), and the surgeon refers to their surgical plan to execute the same operation as they planned. The surgeon can identify the renal structures by manipulating the image in real-time 3D imaging; it allows the

#### **Figure 7.**

*The real-time 3D-virtual surgical simulation can be seen in the TilePro multi-input display on the surgeon's console of daVinci surgical system through digital video interface (DVI) ports on the backside. The simulated surgical plan in 3D volume-reconstructed images with key anatomical structures became available. The surgeon can identify the anatomical structure with ultrasound to complete the planned surgery correctly.*

#### **Figure 8.**

*The 3D-virtual surgical simulation determined that the resection area of the tumor (blue area), tumor (pink area), and regional ischemic area (brown area) by the selective arterial clamping at the third branch of the left renal artery (yellow dot), which was located below the left renal vein.*

*The Three-Dimensional Virtual Surgical Simulation and Surgical Assistance for Optimizing… DOI: http://dx.doi.org/10.5772/intechopen.108773*

#### **Figure 9.**

*A surgeon's console display with an endoscopic surgical view (top) and 3D-virtual surgical simulation (bottom) to identify the targeted vasculature after a renal hilum dissection. The top shows the actual surgical field, the renal arterial branches were already exposed at the second to third branch beyond the left renal vein. The bottom shows a real-time 3D-virtual surgical simulation image adjusted to the surgical field.*

surgeon to find the key anatomical structures and cutting angle to adjust in the real operation field.

The Clinical benefit of the 3D-virtual surgical simulation and surgical assistance. Since 2014, there are some supportive publications reported about the 3D-virtual surgical simulation using this segmentation technology for RAPN from Japan. In 2014, Komai et al. demonstrated the surgical planning and surgical simulation by 3D segmented images for open partial nephrectomy [19]. In addition, in 2015, Isotani et al. reported that the 3D-virtual surgical simulation was able to provide the identification of tumor-specific renal arterial supply, prediction of collecting system opening, and prediction of postoperative renal function. They concluded that this imaging technique might suggest to the surgeons the best adjusted surgical margin size and arterial clamping point by virtual simulation [15]. Ueno et al. demonstrated that segmentation methods showed the prediction of urinary tract opening and the position of the opening as useful preoperative information [25]. Isotani et al. demonstrated in the video report in 2017, they showed the 3D-virtual surgical simulation and surgical assistance allowed for preserving renal function by minimizing the excision margin and limiting the ischemic area [16]. In 2016, Bernhard et al. reported their clinical experience with the 3D printing kidney models made from 3D-virtual surgical simulation with segmentation technology [26]. They demonstrated that this imaging technology also facilitate patients' pre-surgical understanding of their kidney tumor and surgery. As for the surgical outcomes, from Italy, there are some reports using the same segmentation technology. In 2018, Porpigli et al. showed that the 3D-virtual surgical simulation of the kidney with segmentation seems to promote selective ischemia to help in avoiding the global ischemia of the kidney compared to 2D CT [27]. In his report, he noted that in 90% of patients with 3D-virtual surgical simulation, the intraoperative management of the renal pedicle was performed as preoperatively planning, even though, in 39% of the group without 3D simulations group, the renal arterial pedicle management was intraoperatively changed [27].

In 2019, Porpigli et al. also showed that 3D-virtual surgical simulations were more precise than 2D standard imaging for evaluating the surgical complexity for partial nephrectomy. They showed a better perception of tumor depth and its relationships with intrarenal structures by 3D-virtual surgical simulation and resulted in predicting postoperative complications [28]. Additional supportive papers were reported by Bianchi et al. and Schiavina et al. in 2020 [22, 23]. However, even with the highfidelity 3D simulation imaging, there was an absence of support for this imaging technology, which had a significant shortening effect on the total operation time or WIT (warm ischemic time) until 2021. Kobayashi et al. demonstrated in 2020 that the 3D surgical navigation system using the 3D-virtual surgical simulation showed preserving of renal parenchyma in robot-assisted partial nephrectomy, and it might contribute to improvement in postoperative renal function [29].

In 2021, Michiels et al. reported the significant benefit of 3D-virtual surgical simulation with segmentation in decreased warm ischemia time and reduced serious complications with the increased proportion of selective clamping. However, at the same time, they showed that the total operation time had been longer than without the 3D surgical simulation [20]. The longer operation time was due to the requirement of dissection of segmental arterial branches with risk of vascular injury. They concluded that the 3D-virtual surgical simulation and intraoperative guidance, the perioperative medical and surgical management may account for better clinical perioperative outcomes. These published articles supported that 3D-virtual surgical simulation may play an important role to refine patient counseling, surgical decision-making, and pre-and intraoperative planning for RAPN, and it helps to achieve precision surgical strategies and techniques according to the individual patient's anatomy.

#### **4. Future development and options**

Many articles suggested that by using 3D-virtual surgical simulation, the surgeon could have some benefit for Robotic partial nephrectomy. These surgical techniques, which combined with 3D-virtual surgical simulation and intra-op surgical navigation, *The Three-Dimensional Virtual Surgical Simulation and Surgical Assistance for Optimizing… DOI: http://dx.doi.org/10.5772/intechopen.108773*

may allow "Precision Surgery" to preserve renal function by minimizing the excision margin and limiting the ischemic area [16].

The future additional developments with 3D-virtual surgical simulation are the augmented reality (AR) in different surgical interventions [23] or registration of the 3D-virtual surgical simulation such as touch-based registration [19]. Even these some challenging articles have been reported, the accurate registration methods still have several problems or limitations to clinical usage [19]. No group has achieved that fully automated registration with noninvasive way during the current surgical RAPN workflow with quantitatively accessed registration accuracy. The future additional developments with 3D-virtual surgical Also, further areas may contain the automated segmentation method of the renal organs and incorporation of topological organ changes or tissue deformation by the human body status. Because it is known that the kidney has been moving up 10 mm cephalad and 11 mm medially in the flank position, and the respiratory motion makes the shifting the kidney in left-right, anteriorposterior, and cephalad-caudad directions.

These limitations suggested that ideally real-time registration methods to enhance the accuracy are required with endoscope data, updated with intraoperative ultrasound or touch-based registration [19].

#### **5. Conclusion**

Imaging surgery simulation in partial nephrectomy is useful for evaluating the difficulty of surgical procedures and for navigation during surgery planning and surgery, especially those using segmentation imaging technology. It is expected that such image processing technology will become more convenient and practical. In addition, image processing technology is expected to be incorporated and integrated into robot functions.

#### **Additional video materials**

Additional video materials referred to in this chapter can be downloaded at: https://bit.ly/3EDIo7Q.

## **Author details**

Shuji Isotani Department of Urology, Graduate School of Medicine, Juntendo University, Bunkyo, Tokyo, Japan

\*Address all correspondence to: s-isotani@juntendo.ac.jp

© 2022 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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## **Chapter 5**

## Recent Advances and New Perspectives in Surgery of Renal Cell Carcinoma

*Congcong Xu, Dekai Liu, Chengcheng Xing, Jiaqi Du, Gangfu Zheng, Nengfeng Yu, Dingya Zhou, Honghui Cheng, Kefan Yang, Qifeng Zhong and Yichun Zheng*

## **Abstract**

Renal cell carcinoma (RCC) is one of the most common types of cancer in the urogenital system. For localized renal cell carcinoma, nephron-sparing surgery (NSS) is becoming the optimal choice because of its advantage in preserving renal function. Traditionally, partial nephrectomy is performed with renal pedicle clamping to decrease blood loss. Furthermore, both renal pedicle clamping and the subsequent warm renal ischemia time affect renal function and increase the risk of postoperative renal failure. More recently, there has also been increasing interest in creating surgical methods to meet the requirements of nephron preservation and shorten the renal warm ischemia time including assisted or unassisted zero-ischemia surgery. As artificial intelligence increasingly integrates with surgery, the three-dimensional visualization technology of renal vasculature is applied in the NSS to guide surgeons. In addition, the renal carcinoma complexity scoring system is also constantly updated to guide clinicians in the selection of appropriate treatments for patients individually. In this article, we provide an overview of recent advances and new perspectives in NSS.

**Keywords:** renal cell carcinoma, zero ischemia, partial nephrectomy, tumor enucleation, renal carcinoma complexity scoring system

### **1. Introduction**

With the development of screening techniques, increasing numbers of renal tumors are being diagnosed at an early stage without clinical symptoms [1]. Surgical resection remains the cornerstone of renal cell carcinoma (RCC) treatment [2]. Recent studies have shown that renal sparing techniques, such as partial nephrectomy (PN), achieve a comparable tumor prognosis and significantly improve perioperative morbidity and mortality. And guidelines from multiple urological associations recommend PN as the standard of care for early renal cell carcinoma [3, 4]. With the development of laparoscopic nephron-sparing surgery (NSS), urological surgeons

strive to shorten the renal warm ischemia time (WIT) and preserve more renal parenchyma while removing tumor tissue. In order to preserve more renal parenchyma, laparoscopic renal tumor enucleation and renorrhaphy technique including deepsutures running the base of the defect, precise vesselsuture ligation, and no renorrhaphy at all have been developed [4]. In order to shorten the renal warm ischemia time, there are some surgical methods, such as microwave ablation/radio frequency ablation/laser/hydro-jet-assisted zero-ischemia laparoscopic partial nephrectomy (LPN), selective renal artery occlusion/embolization-assisted zero-ischemia laparoscopic partial nephrectomy, unassisted zero-ischemia laparoscopic partial nephrectomy and zero-ischemia laparoscopic renal tumor enucleation, and zero-ischemia laparoscopic partial nephrectomy by re-suturing [5]. Preoperative three-dimensional visualization technology of renal vasculature is increasingly used to implement multiple zeroischemic approaches in laparoscopic nephron-sparing surgery [6].

The Mayo Clinic thrombus classification is widely used to describe levels of inferior vena cava tumor thrombus and is significant to guide the operation for renal cell carcinoma with venous thrombus in the open era [7]. But in the minimally invasive surgery era, Prof. Zhang et al. summarized a large number of surgical experiences of renal cell carcinoma with venous thrombus and put forward the "301 classification" system [8]. The system based on anatomical landmarks in which one grade corresponds to one surgical strategy improves surgical choice in the treatment of renal cell carcinoma with venous thrombus.

In this article, we summarize the various new surgical methods for renal cell carcinoma and describe the advantages and disadvantages of each of these methods. Moreover, we provide an overview of the latest research on RCC surgery and new scoring system which would help physicians to better personalize surgical treatment for patients.

## **2. Introduction of assisted zero-ischemia surgery**

With increasing evidence indicates warm ischemia time (WIT) can have significant impact to minimize the loss of renal function after partial nephrectomy (PN), scientists are committed to reducing warm ischemia time, even achieving zeroischemia surgery. Techniques trying to achieve zero ischemia are as follows.

#### **2.1 Selective renal artery embolization technique**

#### *2.1.1 Methods*

DSA superselective target artery embolization was performed in the interventional operating room 1 to 12 hours before surgery. Seldinger puncture method was used to insert F5 arterial catheter through the right femoral artery, and Yashiro catheter was used to perform renal artery angiography, superselected to the renal tumor supply artery, injected embolic agent, and then angiography was performed again to understand the embolization effect. Then laparoscopic partial nephrectomy with zero ischemia was performed [9].

#### *2.1.2 Results*

At 3-month and 1-year follow-up, the median increase of serum creatinine levels was 0.3 mg/dL and 0.24 mg/dL, respectively, and the median decrease of split renal

function was 9% and 5%, respectively. The median tumor size was 4.2 cm (range, 2.5 to 6.5 cm). The median operative time was 62 minutes (35–220 minutes), the median blood loss was 150 ml (20–800 ml), and the median hospital stay was 3 days (2–12 days). None of the patients had end-stage CKD [10].

#### *2.1.3 Complications*

Complications are urinary tract infection, pulmonary infection, postoperative incision infection, postoperative intestinal obstruction, pelvic effusion and lower extremity venous thrombosis, as well as complications after superselective arterial embolization (low back pain, fever, infection, local hematoma), etc.

#### *2.1.4 Advantages and limitations*

With this technique, bleeding can be effectively stopped during surgery and the survival of the remnant kidney tissue can be maximized. The disadvantages of this technique are as follows. Firstly, superselective artery embolization is not successful in about 20% of cases, which is negatively correlated with the RENAL score. Especially in the face of large and endogenous tumors, the use of DSA to superselectively embolize the tumor to supply the artery needs more theoretical support [10]. Secondly, superselective arterial embolization can lead to edema and gangrene in the area of hand surgery, which brings difficulty to correctly distinguish normal tissue from tumor tissue. It is necessary to be vigilant all the time; otherwise, the tumor is easy to rupture and the positive rate of surgical margin will increase. For beginners, adequate surgical margin should be ensured from the tumor body. Thirdly, the use of iodine contrast and hemostatic agents could lead to contrast medium-induced nephropathy [11].

### **2.2 Selective renal artery occlusion technique**

### *2.2.1 Methods*

Nohara T and colleagues first introduced the concept of this technique in 2008 as a modified form of anatrophic partial nephrectomy [12]. First, the feeding branch of the tumor was determined by angiographic assessment or computed tomography angiography (CTA). During the operation, secondary or even tertiary renal arteries were isolated and vascular clips were used to control the renal segment arteries in the tumor area, and the renal segment arteries were isolated and blocked. The tumor and surrounding renal parenchyma were completely resected 0.5 to 1.0 cm from the tumor margin.

## *2.2.2 Results*

Compared with total renal artery occlusion partial nephrectomy, the operation time and warm ischemia time were longer, and the intraoperative blood loss was more, and the differences were statistically significant (P < 0.05). One month after operation, the serum creatinine and urea nitrogen of the group undergoing superselective renal artery occlusion were lower than those of the group undergoing total renal artery occlusion, and the differences were statistically significant (P < 0.05) [11].

#### *2.2.3 Complications*

The injury of renal vein, renal pelvis, and ureter is a common complication when the renal artery is separated. As for postoperative complications, hematuria is usually caused by inadequate suture of renal pelvis and calyces during operation.

#### *2.2.4 Advantages and limitations*

It can not only provide a bloodless surgical field of view but also minimize the risk of ischemic injury and effectively protect renal function. Since only the branch of renal artery in the tumor area is blocked, the requirement of blocking time will be relaxed, which can allow more time for tumor resection and suture. However, compared with the main renal artery occlusion, the operation time is longer, the wound caused by vascular separation is larger, and the intraoperative bleeding is more [13].

#### **2.3 Laser-assisted technique**

#### *2.3.1 Methods*

The frontal laser fiber was used for vaporesection between 20W and 25W in all cases. The laser has the ability to coagulate and vaporize or cut, depending on the distance of the tip of the fiber from the tissue being resected (5mm or 1–2mm, respectively). After complete resection, the tumor was extracted through an endoscopic specimen bag via the 12- to 15-mm laparoscopic port [14].

#### *2.3.2 Results*

It is a good way to achieve minimally invasive surgery, helps to reduce bleeding in the case of complete tumor removal, and reduces the rate of positive margins [14].

#### *2.3.3 Advantages and limitations*

Carbon dioxide (CO2) laser was the first laser used in clinical practice for partial nephrectomy. However, when neodymium-doped yttrium aluminum garnet (Nd:YAG) laser operated at 1064 nm (a 532-nm version exist for lithotripsy), it has a deeper length of tissue penetration (up to 1 cm) than CO2 laser. Nd:YAG laser revealed promising results with excellent cutting and coagulation properties, but the deeper tissue penetration increased the risk of damage to healthy kidney tissue [11]. The newer thulium:yttrium-aluminum-garnet (Th:YAG) laser was first introduced into clinical practice in 2005. It has a wavelength of 2013 nm in continuous wave mode and could offer complete absorption of laser energy in water, providing superior vaporization and hemostatic properties than those of other lasers, which means the laser allows both excellent coagulation and vaporization/ cutting capabilities [15].

However, laser coagulation and vaporization create a problematic smoke plume that can obscure direct operative vision during resection, as well as the laser does not have the ability to seal larger arterial vessels greater than 2.0mm. Therefore, the potential for bleeding increases with deeper endophytic tumors [16].

*Recent Advances and New Perspectives in Surgery of Renal Cell Carcinoma DOI: http://dx.doi.org/10.5772/intechopen.109444*

#### *2.3.4 Complications*

Severe carbonization sometimes will be produced because of difficulty in control [16].

#### *2.3.5 Advance*

An ideal laser setup should provide accurate and adequate tissue cutting and ablation without causing carbonization, splattering, or excessive smoke. In that case, the operator could avoid the necessity for irrigation and vision would be improved during resection. In addition, in such an ideal setup, hemostasis should be completed safely even in larger blood vessels without suture or additional hemostatic agents. Finally, the ideal laser for the operator should be fast and easy to use [16].

## **2.4 Radio frequency ablation (RFA)-assisted technique**

### *2.4.1 Methods*

After opening the renal fascia, the renal artery was identified and suspended. Fat was removed from the tumor and surrounding tissue. The tumor location was determined by direct vision and laparoscopic ultrasonography. Before RFA, all tumors were biopsied using a 22-gauge TruCore®. To avoid additional puncture, the electrode was introduced through the abdominal wall or a laparoscopic trocar. Intraoperative ultrasonography was used to guide electrode insertion and monitor ablation, which could ensure thermal energy cover the tumor base. RFA was performed for 1 to 3 cycles for 6 to 12 minutes each depending on tumor size and depth [17].

#### *2.4.2 Indications*

The median tumor size was 3.2 cm (2.8–3.9), and the majority (73.1%, n = 133) were exophytic in more than 50% of cases [17].

#### *2.4.3 Results*

Xiaozhi Zhao reported that the glomerular filtration rate did not differ before versus 12 months after radio frequency ablation-assisted surgery, and 3-year cancer specific, cumulative, and progression-free survival was 100%, 97.3% and 96.4%, respectively [17].

#### *2.4.4 Advantages*

As the mass with a rim of normal parenchyma is coagulated with RF energy, minimal blood loss and good visualization were achieved during tumor excision. It can also prevent or delay the decline of renal function to the maximum extent [18].

## *2.4.5 Limitations/complications*

When comes to disadvantages, the first is an increased risk of positive surgical margins due to the difficulty in identifying the tumor margin. For another, the placement of electrodes and the thermal penetration could be complicated by calyceal injury, urinary leakage, and venous injuries. In contrast, the incidence of urinary leakage seems to be higher than that of traditional nephron-sparing surgery (NSS) or tumor enucleation (TE) [18, 19].

## **2.5 Microwave ablation (MWA)-assisted technique**

## *2.5.1 Methods*

After the tumor was localized and dissected, 1 to 3 cycles of MWA were performed lasting 2 to 8 min depending on the tumor size and depth. Zero-ischemia NSS can be achieved using the MWA-TE technique by placement of the MWA electrode to create a relatively avascular plane [5, 20].

## *2.5.2 Indications and contraindications*

For the patients with a single, sporadic, unilateral, organ-confirmed and pathologically diagnosed renal cell carcinoma were included in the study of microwave ablation-assisted technology [14]. And the patients with multiple tumors on ipsilateral kidney, collecting system or renal vein invasion, previous renal surgery history of the operative kidney, or with other renal diseases (such as renal calculi, glomerular nephritis, etc.) are not suitable [5].

## *2.5.3 Results*

In a 3-year follow-up of 100 patients who underwent laparoscopic partial nephrectomy (LPN), Moinzadeh et al. reported overall survival (OS) of 86%, cancer-specific survival of 100% and recurrence-free survival (RFS) of 100%. A recent study of microwave ablation-assisted tumor enucleation for renal cell carcinoma shows no significant difference between preoperative, postoperative, and latest eGFR [21]. And the OS of 3- and 5-year was 99.6% and 98.4%, respectively, and RFS was 98.2% and 95.8%, respectively. Microwave ablation-assisted zero-ischemia laparoscopic technology is considered to be a viable and effective nephron-sparing surgical technique for selected renal tumors, with a low perioperative complication rate and promising mid-to-long-term oncological and functional outcomes [5].

## *2.5.4 Advantages*

MWA causes coagulated cell necrosis by inducing friction of water molecules. Compared to RFA, MWA is more effective for the ablation of larger tumors due to its heat generation mechanism. In clinical practice, we found that MWA has the advantages of higher intratumoral temperature and higher tissue ablation volume in a shorter ablation cycle than RFA [5, 20–22].

### *2.5.5 Limitations/complications*

It carries the risk of affecting the diagnostic accuracy of the cut edge [5].

## **2.6 Hydro-jet-assisted technique**

### *2.6.1 Methods*

Hydro-jet-assisted minimally invasive partial nephrectomy (MIPN) is performed by blunt dissection and dissection of the renal parenchyma using extremely thin, high-pressure water flow. The spread of tumor cells may be caused when hydro-jet dissection is performed for malignant diseases.

## *2.6.2 Results*

Gao and colleagues performed hydro-jet-assisted minimally invasive partial nephrectomy.The average operation time was (103.2 ± 24.5)min, the average intraoperative blood loss was (250.3 ± 80.6) ml, the average perirenal drainage tube induration was (6.3 ± 2.6) days, and the average postoperative hospital stay was (8.3 ± 1.6) days [23].

### *2.6.3 Complications*

The spread of tumor cells may be caused when hydro-jet dissection is performed for malignant diseases [24].

#### *2.6.4 Advantages and limitations*

Water jet uses the kinetic energy of water to separate the human tissue, without any thermal damage, and will not cause damage to the important organs and surrounding tissues [25]. Water jet, with high tissue selectivity and protection, can achieve the purpose of accurate protection of blood vessels, nerves, and canals and reduce the possibility of accidental injury [23].

However, compared with other methods, the cutting speed of water jet is relatively low. Meanwhile, in the process of cutting with water knife, a large amount of water waste liquid will be produced, which may affect the observation of surgical field and the judgment of cutting surface [11].

## **3. Introduction of unassisted zero-ischemia surgery**

#### **3.1 Unassisted zero-ischemia partial nephrectomy**

## *3.1.1 Methods*

To obtain a bloodless field and, consequently, to perform precise tumor excision and renal reconstruction, contemporary partial nephrectomy (PN) techniques typically need hilar clamping, which necessarily imposes ischemic and reperfusion injuries upon the kidney [26]. The unassisted zero-ischemia PN technique aims to reduce or even eliminate these injuries and preserves renal function [27].

In 2011, Gill et al. introduced "Zero-Ischemia" partial nephrectomy as a new technique to perform minimally invasive partial nephrectomy (MIPN) with selective renal artery clamping. Firstly, to precisely guide the clamping of tumor-supplying branches, the feeding branch for the tumor is identified by angiographic evaluation or computed tomography angiography (CTA). Then followed is the microdissection of renal arterial branches. The hilar vessels should be preemptively prepared before the meticulous microdissection and clip ligation of the tertiary or quaternary renal arterial branch which dedicatedly supplies the tumor or the tumor-bearing segment of the kidney [26]. Related clinical studies have been carried out and suggested that selective renal artery clamping can achieve no inferior or even better effect than hilar clamping [28, 29].

Though the selective clamping technique reduces the ischemic renal injury, the ischemic area of selective renal artery clamping is still larger than the tumor area. In addition, it is necessary to dissect tertiary or quaternary renal arteries, prolong the operation time, and increase the stimulation of renal arteries. PN without clamping any artery called off-clamping technique aims to optimize this shortcoming. The operation is similar to on-clamping PN. The renal artery needs to be dissected and marked, but will not be clamped. Renal tumor and part of the kidney are dissected. Then the tumor is resected 0.5-1 cm away from the tumor edge without blocking the renal artery. The renal parenchyma is sutured continuously with inverted thorn thread, or bipolar electrocoagulation is given to stop bleeding and cover the hemostatic material. Drainage tube is indwelled after examination of no active bleeding [30].

#### *3.1.2 Indications and contraindications*

The indication for the application of zero-ischemia PN is not clear. Based on the indications and contraindications of on-clamping PN, the location, number, growth pattern (endogenous/exogenous), and intrarenal size of the tumor are the main factors to consider in operating this technique.

Zero-ischemia PN appears suited for medially located, whether in hilar, central, or polar sites. The medially located tumor or its bearing segment of the kidney is typically supplied by a dedicated secondary, tertiary, or quaternary branch [26]. However, tumors with dense or adherent perirenal fat or short segmental arteries may not be suggested to perform selective arterial clamping [31].

The application of off-clamping remains controversial. Whether under laparoscopic or robotic assist, unacceptable bleeding caused by off-clamping will lead to unclear visual field and difficult to complete high-precision surgery. Thus, off-clamping is limited to the tumors with favorably anatomical features (i.e. small, superficial, exophytic) and technically relatively easy [26].

#### *3.1.3 Results and complications*

The ideal goal of PN is to achieve Trifecta, that is, complete resection of the tumor ensures negative surgical margin, maximum preservation of normal nephron function, and avoidance of short-term and long-term complications. The negative surgical margin is the most important one [32].

In the study reported by GILL, SHAO, and NG, all patients who performed zero-ischemia PN achieve negative surgical margins [26, 28, 33]. In the study reported by SMITH and THOMPSON, the positive rate of tumor surgical margin is not significantly different between zero-ischemia PN and on-clamping PN [34, 35]. The study from WSZOLEK et al. tends to highly selective renal artery clamping can reduce

#### *Recent Advances and New Perspectives in Surgery of Renal Cell Carcinoma DOI: http://dx.doi.org/10.5772/intechopen.109444*

the positive rate of the surgical margin, but the local recurrence rate and the 5-year survival rate in postoperative follow-up are similar [36].

Complications of zero-ischemia PN are similar to those of on-clamping PN due to the similar operation method. The study from WSZOLEK and THOMPSON revealed that on-clamping PN has a higher urine leakage rate and hemorrhage rate than zeroischemia PN, but the results have no significant statistical significance [35, 36].

#### *3.1.4 Advantages and limitations*

That zero-ischemia PN is suited for anatomically favorable tumors results in on-clamping PN having a wider scope of application than zero-ischemia PN. During zero-ischemia PN, the increase in blood loss leads to unclear visual field and more difficult operation. The dissection of the tertiary or quaternary renal arterial branch prolongs the operation time.

But the ischemia time and area are reduced. It helps preserve more renal parenchyma and protects renal function. What's more, for patients with cardiovascular complications, potential renal dysfunction, or old age, ischemia may lead to greater injury, so zero-ischemia technology has a comparative advantage [26].

#### **3.2 Unassisted zero-ischemia tumor enucleation**

#### *3.2.1 Methods*

For zero-ischemia tumor enucleation (TE), retroperitoneal fashion is typically accepted. The location of the tumor is determined according to the preoperative imaging data. The main renal artery needs to be isolated routinely. The resection initiated approximately 2 mm away from the tumor margin. After identifying the pseudocapsule, the surgeon took the pseudocapsule as an anatomic marker to enucleate the tumor from the surface to the bottom using blunt together with sharp dissection [37].

#### *3.2.2 Indications and contraindications*

Similar to PN, TE is mainly suitable for patients with lateral exophytic tumors with early stage, especially T1 renal cell carcinoma, and requires that the tumor has a pseudocapsule that has not been breached. Thus, for the endogenous tumor, the large intrarenal tumor, and the tumor have breached the pseudocapsule, zeroischemia tumor enucleation is not a suitable operation. In addition, the zero-ischemia technique should not be applied to patients with severe bleeding tendency or severe anemia. For T2 renal cell carcinoma, whether using this technique should base on the anatomical features and techniques of surgeons.

#### *3.2.3 Results and complications*

The curative effect of simple enucleation (SE) of renal tumors provides a reference for zero-ischemia tumor enucleation. For localized renal cell carcinoma, there is no significant difference in the positive rate of surgical margin, local recurrence rate, and survival rate between SE and PN [2]. Minervini reported a case of 127 patients who performed robot-assisted SE with a median follow-up of 61 months. There was no recurrence in situ [38]. The 10-year tumor-specific survival rate of SE was 97% [39].

Complications of zero-ischemia enucleation include postoperative bleeding, urinary fistula, short-term and long-term decline of renal function caused by reduced renal parenchyma, and postoperative infection.

#### *3.2.4 Advantages and limitations*

Compared with PN, TE preserves more renal parenchyma to ensure better renal function but has a smaller scope of application due to the oncological and anatomical requirements [37].

Compared with off-clamping TE, the incidence of CKD of zero-ischemia TE is lower [40], and the reduction rate of postoperative GFR is lower [28]. The indexes such as creatinine in the zero-ischemia TE are also better than those in off-clamping TE [18]. But the intraoperative blood loss was higher.

#### **3.3 Sequential preplaced suture Renorrhaphy technique**

#### *3.3.1 Methods*

The method of this surgery was firstly described in 2013 by Emad et al. [41]. It is roughly the same as minimally partial nephrectomy in the process before tumor resection. Notably, sequential preplaced suture renorrhaphy technique is to excise the renal tumor between the tumor edge and the suture replaced through the tissue adjacent to the tumor and modifying placement of the suture real time until the mass is completely excised.

#### *3.3.2 Indications and contraindications*

Similar to other zero-ischemia minimally invasive partial nephrectomy surgeries, sequential preplaced suture renorrhaphy technique is mostly applicable to patients who require eliminating warm ischemia urgently, such as those with solitary kidneys or multiple tumors. As for the size and location of the tumor, it is practical for treating RCCs with small tumor sizes, especially whose diameter is smaller than 3 cm and which are exophytic and peripheral renal tumors. In other words, this technique is limited for treating hilar located tumors.

#### *3.3.3 Results and complications*

The results of this surgery were not worse than other MIPNs. There did not exsit a statistically significant difference between preoperative and 12-month postoperative creatinine and eGFR values [42]. As shown in a previous study [41], median estimated blood loss (EBL) was 192.5 mL while median operative time was 160 minutes, which were similar to other zero-ischemia surgeries. What is more, according to the postoperative pathology findings in multiple investigations, almost all of the tumors treated with it had negative surgical margins and were completely eliminated. After the surgery, postoperative ileus, blood transfusion, and deep vein thrombosis were the main postoperative problems. Another study found the average operating duration was 75 minutes and a 60-ml average blood loss [43]. All 14 cases had negative surgical margins, and there was no postoperative bleeding or urine leakage after surgery. There were no signs of recurrence on a follow-up CT conducted 1–6 months after surgery. However, results of this surgery still need long-term follow-up.

#### *3.3.4 Advantages and limitations*

Compared with other surgeries which need warm ischemia, it avoids renal ischemia reperfusion injury and preserves more renal function. Compared to other straightforward excision without hilar clamping, it improves visibility as a result of less bleeding and helps to excise less normal parenchyma and thereby minimize nephron loss. Moreover, suture placement can be more precisely adjusted in real time, which increases resection precision and lessens the likelihood of a positive margin.

The limited application of this method is to treat tumors with hilar locations. Besides, prepositioning the suture will compress and deform the tumor bed, making tumor removal challenging or erroneous. We still need more sample sizes and longer time to follow-up to verify its effectiveness and oncologic safety during the process of implementation [11].

## **4. Application of the three-dimensional visualization technology of renal vasculature**

The arterial blood supply of renal cell carcinoma is diversified. Generally speaking, the main renal artery is the main blood supply artery for renal tumors. However, extrarenal blood supply arteries often participate in tumor angiogenesis, playing a very important role in tumor blood supply [44, 45]. Borojeni found that about 26 patients had multiple renal segmental arterial blood supply through renal arteriography of 60 patients with stage T1 renal carcinoma [46].

In recent years, with the development of minimally invasive technology and the implementation of the concept of "zero ischemia," laparoscopic partial nephrectomy more often uses selective renal artery clamping. High-selective clamping of the segmental artery which irrigated the tumor can not only obtain good effect of blocking tumor blood supply but also effectively reduce the renal warm ischemia time of patients and reduce the risk of surgery. Francesco Porpigilia et al. studied 52 cases of robot-assisted partial nephrectomy and showed that compared with the control group, the preoperative hyperaccuracy three-dimensional (HA3D) reconstruction technology can accurately display the course and surrounding structures of renal tumor-related renal segment branches, thus improving the success rate of clamping renal tumor-related renal artery branches during operation [6].

As an imaging tool of digital medical technology, three-dimensional visualization uses computer image processing technology to process CT or MRI image data through the workstation, import the data into the three-dimensional visualization imaging software system for segmentation, fusion, calculation, rendering and other operations, and build a three-dimensional model. The model can describe and explain the precise location, spatial anatomy, shape and volume of target lesions, related organs and vascular systems from multiple angles and in an all-round way and can provide clinicians with intuitive visual experience and full quantitative information. It is of high value for accurate preoperative diagnosis, planning of individualized surgical programs, and prediction of surgical risks. Further studies have shown that threedimensional visualization can clearly display the number, size, branching pattern, shape, and positional relationship with renal tumors of the aberrant renal arteries, thereby helping the surgeon to determine the anatomical shape of renal blood vessels and the location of ectopic blood vessels before surgery and provide accurate guidance intraoperative operation [47].

## **5. Advances in renal carcinoma complexity scoring systems**

Currently available nephrometry scores can arbitrarily be grouped into those based on a visual anatomical assessment of a renal mass and those based on a mathematical assessment.

Most of the scores are included in this group because they are based on an immediate visual evaluation. The RENAL and PADUA scores assess the location of the tumor, its percentage of penetration into the kidney, and its relationship with the renal sinus or urinary collecting system [48]. The Diameter-Axial-Polar (DAP) score determines the size of kidney mass and distance from two reference lines: axial and polar lines [49]. The Zonal Nearness-Physical-Radius Organization (NePhRO) score provides five parameters that mirror RENAL and PADUA scores. The difference is that it divides the kidney into three zones (zone 1: kidney parenchyma; zone 2: medullary and sinus; and zone 3: collecting system and hilum) and employs another dimensional scale to determine renal mass dimension [50]. Otherwise, the Renal Pelvic Score (RPS) deviates from the previously mentioned scores. Indeed, it evaluates the presence of an intrarenal or extrarenal pelvis referring to a sagittal line which passes through the kidney hilum [51]. The Surgical Approach Renal Ranking (SARR), a different score, has the same characteristics as the RENAL, PADUA, and Zonal NePhRO scores but offers a scoring system range from 0 to 4, rendering it possible to achieve a more precise stratification of renal masses [52]. The majority of scores take the tumor's longitudinal position into account; however, the Zhongshan score also takes into account the transversal tumor, which includes its lateral, central, and medial locations [53]. Recently, developments in the Simplified PAdua REnal (SPARE) nephrometry system has combined the key elements of both the nephrometry scores to create a maximum tumor size, exophytic rate, renal sinus involvement, and tumor rim location-based score [54]. The Arterial-Based Complexity (ABC) scoring system takes the order of vessels needed to be transected/dissected into account. The four scores (1, 2, 3S, and 3 H) evaluated are related to the neoplasm interaction with interlobular and arcuate arteries, interlobar arteries, segmental arteries, or in close proximity of the renal hilum, respectively [55]. The Peritumoral Artery Scoring System (PASS) is another score based on the vasculature [56]. Based on the number and diameter of the peritumoral arteries, this three-dimensional score assigns a complexity level to tumor dissection. The Mayo Adhesive Probability (MAP) score, in contrast to the scores stated above, assesses the perinephric fat thickness as a means to anticipate its adhesion to the kidney, which could result in a more complicated resection [57].

This category necessitates a thorough imaging examination and is based either on a mathematical or visual evaluation of the tumor. The first one, the Centrality Index (C-index), categorizes the complexity of the tumor according to the mathematical distance between the tumor and kidney center [58]. The Renal Tumor Invasion Index (RTII), which is the ratio of tumor invasion depth, is defined as the maximal distance that tumor invades into parenchyma and the parenchymal thickness of the kidney immediately adjacent to the tumor [59]. Both the tumor Contact Surface Area (CSA) and the Renal And Ischemia Volume (RAIV) use measurements of the mass radius and diameter. Additionally, the RAIV demands that the cross section of the resected and ischemized renal parenchyma be measured. [60, 61]. In a similar manner, the Zero Ischemia Index (ZII) shows the outcome of multiplying the tumor's depth in the kidney parenchyma by its diameter. [62]. The Coefficient,

#### *Recent Advances and New Perspectives in Surgery of Renal Cell Carcinoma DOI: http://dx.doi.org/10.5772/intechopen.109444*

Location, Anterior boundary, Multi-boundary, and Posterior boundary (CLAMP) score is the only used to determine the complexity of vascular. This three-dimensional (3D) imaging-based score assesses the anatomy of the arteries that supply the renal tumor. This instrument could estimate the effectiveness of segmental artery clamping [62].

The Mayo Clinic thrombus classification is widely used to describe levels of inferior vena cava tumor thrombus and is significant to guide the operation for renal cell carcinoma with venous thrombus in the open era [7]. But in the minimally invasive surgery era, Prof. Zhang et al. summarized a large number of surgical experiences of renal cell carcinoma with venous thrombus and put forward the "301 classification" system. The system based on anatomical landmarks in which one grade corresponds to one surgical strategy improves surgical choice in the treatment of renal cell carcinoma with venous thrombus. The right renal vein tumor thrombus was Level 0, and the surgical strategy was radical resection of the right kidney; left renal vein tumor thrombus can be divided into Level 0a and 0b according to whether it exceeds the superior mesenteric artery [8]. In 0a, radical resection of the left kidney is performed. In 0b, left renal artery embolism is performed before operation. First, the left renal vein and inferior vena cava are disconnected in the left lateral position, and then radical resection of the left kidney is performed in a different position. The inferior vena cava tumor thrombus below the first porta hepatis was level I, which did not need to turn over the liver, only needed to lift the liver and cut off 1–3 short hepatic veins. The level from the first porta hepatis to the second porta hepatis is level II, and it is necessary to turn the right hepatic lobe, without blocking the hepatic blood flow, and disconnect 2 to 5 short hepatic veins. The level from the second hepatic portal to the diaphragm is Level III, which requires turning the left and right hepatic lobes, and blocking the portal blood flow. During the operation, venous-venous bypass is performed according to the situation, and more short hepatic veins are cut off; Level IV is above the diaphragm [63]. Cardiopulmonary extracorporeal circulation should be established to block the superior vena cava and the inferior vena cava above the diaphragm. Thoracoscopic surgery should be performed to remove the atrial tumor thrombus and then block the hepatic portal vessels, and the distal inferior vena cava and its branches. For level 0 or 0a tumor thrombus, laparoscopic surgery is the first choice. For 0b or inferior vena cava tumor thrombus, robotic surgery is the first choice. If the tumor is large, has a complex surgical history, and the function of organs such as the heart is not complete, and it is necessary to shorten the operation time or establish venous bypass, open surgery is the first choice.

## **6. Conclusion**

Most cases of RCC have no clinical symptoms but are diagnosed accidentally. With the development of diagnostic technology, the incidence of patients diagnosed with RCC has increased rapidly over the past decades. For the majority of patients diagnosed with RCC, choosing the appropriate treatment is the primary means to improve their prognosis. Therefore, knowing the latest surgical progress and being familiar with the renal carcinoma complexity scoring system could help doctors design more individualized and appropriate surgical procedures for patients, allowing surgeons to preserve more renal parenchyma while fully removing the tumor.

## **Author details**

Congcong Xu1 , Dekai Liu2 , Chengcheng Xing2 , Jiaqi Du2 , Gangfu Zheng2 , Nengfeng Yu2 , Dingya Zhou<sup>2</sup> , Honghui Cheng2 , Kefan Yang2 , Qifeng Zhong2 and Yichun Zheng1,2\*

1 The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China

2 The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, China

\*Address all correspondence to: 2101090@zju.edu.cn

© 2022 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

*Recent Advances and New Perspectives in Surgery of Renal Cell Carcinoma DOI: http://dx.doi.org/10.5772/intechopen.109444*

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Section 3
